Microfabrication by hot embossing and injection molding at LASTI
微加工技术
7.2 与生物芯片制备相关的微加工技术一提起“生物芯片”，人们很自然就会联想到近几十年来曾使我们的生产和生活发生重大变化的集成电路芯片，因此也常常把它理解为一种利用生物分子实现计算和数据处理功能的芯片。
的确有不少人在进行这种生物计算机的研究，但我们这里所说的生物芯片是指目前发展非常迅速的一项热门技术。
它与集成电路芯片有着本质区别：它处理的并不是电信号，也不具有运算功能，而是一种以生物分子为处理对象、执行生化分析检测的微型设备。
不过二者还是有很密切的联系，除了都有集成化、微型化、可对信号进行并行处理等特点以外，它们在制作工艺和材料方面也很相似。
生物芯片的制备所依赖的正是集成电路工业中应用十分成熟的光学光刻技术（photolithography）和微机电系统(Micro Electromechnical System, MEMS)及其他精密仪器加工中所采用的各种微细加工方法，如反应离子刻蚀(Reactive Ion Etching)、LIGA(Lithograghie, Galvanoformung und Abformung) 技术、激光切削/打孔（Laser Ablation/Drilling）、压模（Imprinting Method）, 微注塑（Microinjection Molding），热塑（Hot Embossing）等等[1]，在这里我们把它们统称为微加工（Microfabrication）技术。
简单地说，生物芯片是指能对生物分子进行快速并行处理和分析的厘米见方的固体薄型器件[2]。
按其结构及工作机理可将其分为微阵列芯片（Microarray chip）和微流体芯片(Microfluidic chip)两大类[3]。
微阵列芯片是将基因的片段（DNA或RNA）、蛋白质（如抗体）、细胞组织等生物样品，以微点样技术或其它技术固定在玻璃片等基片上制作形成的。
而微流体芯片则是微阵列芯片的延伸（有人将微阵列芯片称为第一代生物芯片，而将微流体芯片称为第二代生物芯片），它通过在玻璃、塑料、硅片等基底材料上加工出用于生物样品分离、反应的各种微结构以及用于液体样品输运和控制的微泵、微阀等器件，将生命科学中许多不连续的过程如样品制备、化学反应和分离检测等步骤移植到芯片中并使其连续化和微型化，以获得所谓的微型全分析系统（Micro Total Analytical System，μTAS）或缩微芯片实验室（Lab –on-a-chip）。
翻译 1
Mg-Al-Zn合金组织的晶粒尺在摩擦搅拌的依赖性弱搅拌处理的Y.N.王，a,b C.I.张，a C.J.李，a H.K.林a,c和黄祚芊a,*a材料科学与工程学院;纳米科学中心和纳米技术，国立中山大学圣大学，高雄804，台湾，中华民国b材料科学与工程学院，大连理工大学，大连116024，中国研究所c工研院南，工业技术研究院，台南县734，台湾，中华民国收到2006年4月25日;经修订的2006年5月18日;接受二零零六年六月七日可在网上二零零六年七月五日摘要在Mg-Zn-Al系合金热挤压加工通常表现出较强的粒度屈服应力的依赖。
然而，相同的摩擦搅拌处理的Mg-Zn-Al系合金的样品表现出弱得多的晶粒尺寸的依赖。
高施密特因子摩擦搅拌处理的样品在0.3左右，负责在的Hall-Petch关系的低参数。
关键词：镁合金;搅拌摩擦加工;纹理;晶粒尺寸的依赖镁合金已经吸引了运输车辆制造越来越大的兴趣，因为它们可以提供一个相当大的重量减少的结构。
然而，他们的延展性较差，由于在室温下的六边形结构可滑移系的数量有限，可能会限制其广泛应用。
另一方面，在镁合金的晶粒尺寸强化效率比以Al和其它合金高得多[1]，这意味着晶粒细化镁合金是更有利。
大量的研究集中在镁合金的微结构上的修改已经进行，以提高和控制的机械性能[2-12]。
在镁合金中，存在基础和非基础滑移系之间的临界剪切应力（CROSS）有很大差异[13]，这引起了严重的各向异性的机械性能。
其结果是，当变形镁合金具有强的晶体学织构在其微观结构，它们的机械性能显著由质地除了晶粒尺寸的影响[4-7,12,14]。
最近，研究搅拌摩擦加工（FSP）已经证明，有效的微观组织均匀化和细化可在镁基合金可以实现为严重的塑性变形和动态再结晶的结果。
已经发现该纹理具有强烈的不均匀分布沿着焊接工具的销柱表面基面的积累也带出，在搅拌区[8,15]。
有大量的报道[6,16-18]对晶粒尺寸和镁合金的基础上的Hall-Petch关系机械性能的关系之间的相关性。
Hot Embossing Microfabrication.ppt
Parametric study to determine number of cartridges
Heating Subsystem: Thermal Analysis (Cont..)
Appropriate zone configuration of heating cartridges for
Advantages of Hot Embossing System
Cost effective – Easy manufacturability. Time efficient – Fast process. Fabrication of high aspect ratio features. Bio-Compatible surfaces – Polymer substrates
Analysis
Forcing System used to provide embossing force.
Forcing provided by a Dual Column Floor Mounted Frame material testing system by Instron Corporation model 5800.
Heating Silicon & Polymer above glass transition temperature (Tg).
Applying load by pressing the silicon tool on polymer at certain embossing pressure.
Schematic Representation of Hot Embossing Setup
Hot Embossing Conceptual Solid Models
奈米压印(微影)技术简介PPT
何謂LIGA及目的
• LIGA結合了：光刻術(Lithography)、電鍍鑄模技術 (electroforming)，以及微成形之模造(molding)量產技術。
• 所適用的材料範圍包括半導體、金屬、高分子及陶瓷等。 • 可看成傳統機械的模具產業，但尺寸在微奈米。
目的： • 可用於製造高深寬比之微結構。最大可達100的高深寬
熱壓式奈米壓印技術：熱壓 B17 (1999) 2965-2969
• 合金或複合電鑄：製作低應力、高硬度 熱壓式奈米壓印技術：熱壓
- X光之光罩成本高昂，製作費時 - 熱壓：<150 C、50 bar、3min (300nm厚)
- 結構之高深寬比(5較小5(0~20H) v)、強韌、耐撞擊與耐磨耗之模具。
比。 • 可製作複雜之3D結構。 • 具較強之結構強度與電、磁致動特性。 • 實現機器縮小化的夢想。
13
1. 曝光(打斷高分子鍵結)
LIGA 技術簡介
4. 脫模-金屬模仁(溶除高分子)
2. 顯影(溶除較小分子量之高分子)
5. 成型(熱壓成型或紫外線成型)
3. 電鑄(+研磨)
6. 脫模-複製品(移除金屬模仁)
因鎳具有容易電鑄及抗腐蝕性佳的特性。但是 彈性模數(modulus of elasticity)
Nanoimprint (奈米壓印)
其質軟(硬度250Hv)，適較無磨耗問題的塑膠 40nm-Co74Cr6Pt20/40nm-Ti
1 HCl : 3 HNO3
結構。 光學透鏡(molding material)
因此整個技術重點便在與良率提升39模仁與壓印之材料基板之平行度基板之全城厚度變異基板之表面粗糙度光阻均勻塗佈技術曝底層塗佈烘烤置入透明模仁紫外線硬化型高分子pmma塗佈烘烤置入模仁光阻去除source
纳米管制作皮肤感应器 翻译 中英
最后译文：纳米管弹性制作出皮肤般的感应器美国斯坦福大学的研究者发现了一种富有弹性且透明的导电性能非常好的薄膜，这种薄膜由极易感触的碳纳米管组成，可被作为电极材料用在轻微触压和拉伸方面的传感器上。
“这种装置也许有一天可以被用在被截肢者、受伤的士兵、烧伤方面接触和压迫的敏感性的恢复上，也可以被应用于机器人和触屏电脑方面”，这个小组如是说。
鲍哲南和他的同事们在他们的弹透薄膜的顶部和底部喷上一种碳纳米管的溶液形成平坦的硅板，覆盖之后，研究人员拉伸这个胶片，当胶片被放松后，纳米管很自然地形成波浪般的结构，这种结构作为电极可以精准的检测出作用在这个材料上的力量总数。
事实上，这种装配行为上很像一个电容器，用硅树脂层来存储电荷，像一个电池一样，当压力被作用到这个感应器上的时候，硅树脂层就收紧，并且不会改变它所储存的电荷总量。
这个电荷是被位于顶部和底部的硅树脂上的纳米碳管测量到的。
当这个复合膜被再次拉伸的时候，纳米管会自动理顺被拉伸的方向。
薄膜的导电性不会改变只要材料没有超出最初的拉伸量。
事实上，这种薄膜可以被拉伸到它原始长度的2.5倍，并且无论哪种方向不会使它受到损害的拉伸它都会重新回到原始的尺寸，甚至在多次被拉伸之后。
当被充分的拉伸后，它的导电性喂2200S/cm，能检测50KPA的压力，类似于一个“坚定的手指捏”的力度，研究者说。
“我们所制作的这个纳米管很可能是首次可被拉伸的，透明的，肤质般感应的，有或者没有碳的纳米管”小组成员之一Darren Lipomi.说。
这种薄膜也可在很多领域得到应用，包括移动设备的屏幕可以感应到一定范围的压力而不仅限于触摸；可拉伸和折叠的几乎不会毁坏的触屏感应器；太阳能电池的透明电极；可包裹而不会起皱的车辆或建筑物的曲面；机器人感应装置和人工智能系统。
其他应用程序“其他系统也可以从中受益—例如那种需要生物反馈的—举个例子，智能方向盘可以感应到，如果司机睡着了，”Lipomi补充说。
Microbial Bioprocessing Technology Sample
Microbial Bioprocessing TechnologySampleMicrobial bioprocessing technology is a fascinating field that involves the use of microorganisms to produce various products through fermentation processes. This technology has gained significant attention in recent years due to its numerous applications in industries such as pharmaceuticals, food and beverage, agriculture, and environmental remediation. By harnessing the power of microbes, scientists and researchers are able to create sustainable and efficient processes for the production of valuable compounds. One of the key advantages of microbial bioprocessing technology is its ability to produce high-value products in a cost-effective and environmentally friendly manner. Unlike traditional chemical processes, microbial fermentation can be carried out under mild conditions, reducing the need for harsh chemicals and energy-intensive processes. This not only helps to lower production costs but also minimizes the environmental impact of manufacturing processes. Additionally, microbial bioprocessing technology allows for the production of complex molecules that are difficult to synthesize using traditional methods, opening up new possibilities for drug discovery and development. In the pharmaceutical industry, microbial bioprocessing technology plays a crucial role in the production of antibiotics, vaccines, and other therapeutic agents. By using genetically engineered microbes, researchers are able to optimize the production of these valuable compounds, leading to increasedyields and improved purity. This has the potential to revolutionize the way we treat diseases and combat antibiotic resistance, offering new hope for patients around the world. Furthermore, microbial bioprocessing technology can also be used to produce biofuels, bioplastics, and other sustainable materials, helping to reduce our reliance on fossil fuels and mitigate the effects of climate change. From a scientific perspective, microbial bioprocessing technology offers a wealth of opportunities for research and innovation. By studying the metabolic pathways of microorganisms, researchers can gain valuable insights into how these organisms produce valuable compounds and adapt to different environments. This knowledge can then be applied to the development of novel bioprocessing strategies, leading tothe discovery of new products and processes with a wide range of applications. Furthermore, microbial bioprocessing technology provides a platform for interdisciplinary collaboration, bringing together experts from various fields to tackle complex challenges and drive scientific progress. On a personal level, the potential of microbial bioprocessing technology to improve human health and well-being is truly inspiring. As someone who is passionate about science and innovation, the idea of harnessing the power of nature to create life-saving medications and sustainable materials fills me with a sense of awe and wonder. The prospect of being able to contribute to this exciting field and make a positive impact on society is both humbling and exhilarating. I look forward to seeing how microbial bioprocessing technology continues to evolve and shape the future of industry and research. In conclusion, microbial bioprocessing technology holds immense promise for the production of valuable compounds, the development of new treatments, and the advancement of scientific knowledge. By leveraging the unique capabilities of microorganisms, researchers are able to create sustainable and efficient processes that have the potential to transform multiple industries. As we continue to explore the possibilities of microbial bioprocessing technology, it is clear that this field will play a crucial role in addressing global challenges and improving the quality of life for people around the world. I am excited to see what the future holds for this dynamic and rapidly evolving field, and I am eager to be a part of the journey towards a more sustainable and innovative future.。
Microbial Biotransformation Technology
Microbial Biotransformation Technology Microbial biotransformation technology is a fascinating and innovative field that holds great promise for addressing various environmental and industrial challenges. This technology involves the use of microorganisms to transformorganic compounds, such as pollutants, into less harmful or even beneficial substances. By harnessing the metabolic capabilities of microbes, researchers and engineers are exploring new ways to remediate contaminated sites, produce valuable chemicals, and enhance the sustainability of various industrial processes. However, despite its potential, microbial biotransformation technology also presentsseveral challenges and limitations that must be carefully considered. One of the most significant advantages of microbial biotransformation technology is itsability to degrade and detoxify a wide range of pollutants. Microorganisms have evolved diverse metabolic pathways that enable them to break down complex organic molecules, including pesticides, petroleum hydrocarbons, and industrial solvents. By leveraging these natural capabilities, scientists can design bioremediation strategies to clean up contaminated soil and water, offering a more sustainableand cost-effective alternative to traditional remediation methods. Furthermore, microbial biotransformation can be applied to the treatment of wastewater and the mitigation of air pollution, contributing to the protection of ecosystems and human health. In addition to environmental remediation, microbial biotransformation technology has the potential to support the development of green chemistry and biomanufacturing processes. By using microbial enzymes and pathways, researchers can bioengineer microorganisms to produce valuable chemicals, pharmaceuticals, and biofuels from renewable feedstocks. This approach offers a more sustainable and resource-efficient means of chemical synthesis, reducing the reliance on petrochemicals and minimizing the generation of hazardous byproducts. Moreover, the use of microbial biotransformation in industrial bioprocesses can contribute to the transition towards a bio-based economy, where biological resources are utilized in a more circular and environmentally friendly manner. Despite these promising applications, microbial biotransformation technology faces several challenges that must be addressed to realize its full potential. One ofthe key limitations is the complexity of microbial metabolic pathways and thevariability of microbial behavior in different environmental conditions. Designing effective biotransformation processes requires a deep understanding of microbial physiology, genetics, and ecology, as well as the interactions between microorganisms and their chemical substrates. Additionally, the scalability and economic feasibility of microbial biotransformation processes remain important considerations, especially when applying this technology to large-scale industrial applications. Furthermore, the potential risks associated with the release of genetically engineered microorganisms into the environment raise concerns about the regulation and containment of microbial biotransformation technologies. While engineered microbes can offer unique advantages for bioremediation and biomanufacturing, there is a need to carefully assess their ecological impact and establish stringent safety measures to prevent unintended consequences. Public perception and acceptance of microbial biotransformation also play a critical role in shaping the regulatory framework and ethical considerations surrounding the use of this technology. In conclusion, microbial biotransformation technology holds great promise for addressing environmental challenges, advancing green chemistry, and promoting sustainable industrial practices. By harnessing the metabolic capabilities of microorganisms, researchers and engineers can develop innovative solutions for pollution remediation, chemical synthesis, and bioprocess optimization. However, the complexity of microbial metabolism, the scalability of biotransformation processes, and the regulatory considerations pose significant challenges that require careful attention. As the field of microbial biotransformation continues to evolve, interdisciplinary collaboration and responsible innovation will be essential for realizing the full potential of this technology while ensuring its safe and sustainable implementation.。
微机械与微细加工技术
100gです。主軸を回すモータの定格動力は1.5Wで、乾電池４個（直流6V）で動きます。普通の旋盤と比 較すると、大きさ約1/50、重さ約1/5000、モータの動力は1/500以下になります。
写真の一番左が刃物台で、バイト（切削工具）を固定します。主軸に材料を固定し、１分間に１万回転 の速度で回転させます。そして、X-Y送り機構で切込みを与え、材料を削ります。小型化する上で特に工 夫した点は、X-Y送り機構です。ここには圧電素子（電圧を加えると伸び縮みする性質を持ったセラミック ス）を使用しています。
1. 微系统技术的含意和特点
试作一个比较: 生物或者超大规模集成电路是由大量 微小单元构成的复杂系统，它们都具有十分复杂和高级的 功能。而与它们相比，机械给人的印象则是粗大和功能单 一。下表给出了生物、集成电路和机械系统的相互比较。 从基本单元的尺寸来看，生物以分子作为单元在nm量级、 集成电路在um量级，而机械在mm量级。
3. 微加工和微机械电子系统，江刺正喜 藤田博之 五十岚
伊势美 和杉山进，培风馆，1992年。 4.Methodology for the modeling and simulation of microsystems, by Bartlomiej F. Romanowicz, Kluwer Academic Publishers, 1998
生物、集成电路和机械的比较
功能
生物 高级
集成电路 中等
机械 低
单元数(复杂程度) 多(极其复杂) 中(复杂)
少(简单)
微纳米流动和核磁共振技术
微纳米流动和核磁共振技术英文回答：Microfluidics and nuclear magnetic resonance (NMR) are two important technologies that have revolutionized various fields of science and engineering.Microfluidics refers to the study and manipulation of fluids at the microscale level, typically in channels or chambers with dimensions ranging from micrometers to millimeters. It allows precise control and manipulation of small volumes of fluids, enabling a wide range of applications such as chemical analysis, drug delivery systems, and lab-on-a-chip devices. Microfluidic devices are often fabricated using techniques such as soft lithography, which involve the use of elastomeric materials to create microchannels and chambers.NMR, on the other hand, is a powerful analytical technique that utilizes the magnetic properties of atomicnuclei to study the structure and dynamics of molecules. It is based on the principle of nuclear spin, which is the intrinsic angular momentum possessed by atomic nuclei. By subjecting a sample to a strong magnetic field and applying radiofrequency pulses, NMR can provide information about the chemical composition, molecular structure, and molecular interactions of the sample. NMR has diverse applications in fields such as chemistry, biochemistry, medicine, and materials science.Microfluidics and NMR can be combined to create powerful analytical tools for studying various biological and chemical systems. For example, microfluidic devices can be used to precisely control the flow of samples and reagents, while NMR can provide detailed information about the composition and structure of the samples. This combination has been used in the development ofmicrofluidic NMR systems, which allow rapid and sensitive analysis of small sample volumes. These systems have been applied in areas such as metabolomics, drug discovery, and environmental monitoring.中文回答：微纳米流体力学和核磁共振技术是两种重要的技术，已经在科学和工程的各个领域引起了革命性的变化。
38 Microwave specific effects in organic synthesis
Microwave specific effects in organic synthesis:A proposed model fromthe solvent-free synthesis of monoglycerylcetyldimethylammonium chlorideSatoshi Horikoshi a,*,Motoki Fukui b ,Koji Tsuchiya c ,Masahiko Abe b ,Nick Serpone d,**aResearch Institute for Science and Technology,Tokyo University of Science,2641Yamazaki,Noda,Chiba 278-8510,JapanbDepartment of Pure and Applied Chemistry,Faculty of Science and Technology,Tokyo University of Science,2641Yamazaki,Noda,Chiba 278-8510,Japan cDepartment of Applied Chemistry,Faculty of Science Division I,Tokyo University of Science,1–3Kagurazaka,Shinjuku-ku,Tokyo 162-8601,Japan dGruppo Fotochimico,Dipartimento di Chimica Organica,Universita di Pavia,Via Taramelli 10,Pavia 27100,Italya r t i c l e i n f o Article history:Received 17March 2010In final form 6April 2010Available online 9April 2010a b s t r a c tMonoglycerylcetyldimethylammonium chloride was synthesized from 3-chloro-1,2-propanediol (CP)and N ,N -dimethylhexadecylamine (DMHA)in 2-propanol in solvent-free conditions to exam-ine microwave specific effects.None were evident in homogeneous 2-propanol media under temperature conditions identical to conventional heating.In contrast,heterogeneous solvent-free conditions brought out specific microwave effects as evidenced by variant product yields (130°C;30min):62%by micro-wave and 47%by conventional heating.This variance is attributed to thermal conduction and localized hot spots formed under microwave irradiation.The model proposed for the solvent-free synthesis consid-ers hydrophilic 3-chloro-1,2-propanediol molecules form H-bonded domains (size,2–20l m)preferen-tially heated by the microwaves and dispersed in a sea of hydrophobic N ,N -dimethylhexadecylamine molecules.Ó2010Elsevier B.V.All rights reserved.1.IntroductionMicrowave heating has become a widely employed tool in or-ganic synthesis since it improves product yields and enhances the rate of reactions,as well as being a safe and convenient method for heating reaction mixtures to elevated temperatures [1].In this context,various discussions continue to appear in the literature about the elusive specific microwave (non-caloric)effect(s)in or-ganic synthesis besides the utilization of microwaves as a simple heat source [2,3].In many examples,the specific microwave effect claimed in the past could easily be attributed to thermal (caloric)effects.Microwave heating can be very rapid,producing heat pro-files that are not easily accessible by other heating techniques such as oil-bath heating.This notwithstanding,however,the non-caloric effect of the microwaves may have some exceptional impact on syntheses.In an earlier report of organic syntheses that involved reactions of radicals [4,5],the reactants were activated by micro-wave irradiation while maintaining the temperature at ambient conditions.This led to relatively high product yields and to a signif-icant minimization of generated side products (impurities),an important attractive feature of this methodology.In those experi-ments,whether the effect was a non-thermal effect of the micro-waves or a thermal effect at the microscopic level was not discussed.To date,evidence of a mechanism of the non-thermal ef-fect(s)often eludes experimentation as it requires precise temper-ature measurements whenever microwave dielectric heating is compared to conventional heating [6,7].In this regard,Stuerga and Gaillard [8,9]have used a thermodynamic model to describe the specific behavior of the microwaves’electromagnetic energy in chemical reactions.In microwave-assisted reactions,both the heating and the thermal conduction mechanisms are different from those of conventional heating as described earlier in our syn-thesis of an ionic liquid [10].This short Letter reports an examination of the microwave spe-cific effect and proposes a model based on thermal conduction occurring at the microscopic level in the synthesis of the monog-lycerylcetyldimethylammonium chloride surfactant in homoge-neous 2-propanol media and under solvent-free heterogeneous conditions.2.Experimental setupMonoglycerylcetyldimethylammonium chloride (MGCA)was synthesized under reflux conditions with Tokyo Chemical Industry,Co.,Ltd.reagents 3-chloro-1,2-propanediol (CP;5.9g;0.053mol)and N ,N -dimethylhexadecylamine (DMHA;12.6g;0047mol)in 2-propanol (7.7mL)by microwave irradiation and by conventional heating at ca.95°C (reaction (1))in a reactor setup described ear-lier [11].0009-2614/$-see front matter Ó2010Elsevier B.V.All rights reserved.doi:10.1016/j.cplett.2010.04.011*Corresponding author.**Corresponding author.E-mail addresses:horikosi@rs.noda.tus.ac.jp (S.Horikoshi),nick.serpone@unipv.it (N.Serpone).Chemical Physics Letters 491(2010)244–247Contents lists available at ScienceDirectChemical Physics Lettersj o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /c p l e ttCl OHOHN C16H (CP)(DMHA)NHOOHC16H33Cl+(MGCA)OBð1ÞIn the former case,the three-neckflask(75mL)containing the sam-ple solution was positioned at the maximum of the microwaves’electricfield in the microwave waveguide(2.45GHz;WRJ-2)with the position adjusted with a three stub tuner and a short plunger; continuous microwave irradiation was provided by an Arios Inc.2.45GHz microwave generator(maximal power,200W).In con-ventional heating,an oil bath was used to carry out the synthesis for comparison with microwave heating under otherwise identical temperature conditions.The2-propanol solvent was subsequently removed by evaporation,followed by addition of n-butanol to theresidue.The resulting butanolic solution was poured into water sat-urated with NaCl in a separating funnel.After vigorous agitation the lower aqueous phase was separated from the upper organic phase, following which the n-butanol solvent was removed by distillation. No glycerin was detected in the upper phase by TLC techniques.The residue obtained after distillation was recrystallized3times from acetone–ethanol mixtures to give a white powder of high purity [12]as evidenced by300-MHz1H NMR spectrometry(CDCl3):d (ppm)=0.86(3H,t,C H3–(CH2)14–),1.25(28H,m,–(C H2)14–),1.78 (2H,d,–(CH2)14–C H2–N+),3.33(6H,t,–N+(C H3)2–CH2–),3.44–3.82 (4H,m,–C H2–CH(OH)–C H2–), 4.42(1H,b,–CH2–C H(OH)–CH2–), 4.83(1H,d,–CH2–CH(O H)–CH2–),5.78(1H,t,–CH2–O H).FAB-mass spectra showed m/z=344.35.Elemental analysis of the product gave results within experimental error(<0.4%)of theoretical expec-tations[12].The rate of increase of temperature in the oil-bath heating method was maintained at levels identical to those used for the microwave heating method,so as to avoid differences in synthetic yield that may be caused by differences in temperature between microwave and oil-bath heating.Temperatures were measured precisely using a K-type thermocouple prior to which we verified with an opticalfiber thermometer that the thermocouple was not affected by the microwaves.In another exploratory experi-ment,continuous15-W(applied power)microwave irradiation of the reactants showed a rate of temperature rise of0.15°C sÀ1for the solution,whereas for the oil-bath heating method the rate was0.08°C sÀ1for a power consumption of400W.In this manner, the oil-bath heating rate could not be matched to the microwave heating rate.To overcome this mismatch,the reactor wasfirst soaked in the pre-heated oil bath and the time profile of the rate of temperature rise determined,following which the time profile of the rate of temperature rise of the reactants under microwave irradiation was matched to that of the oil-bath heating by adjust-ing the applied power of the microwaves.3.Results and discussion3.1.Synthesis of the MGCA surfactant in2-propanol mediaThe time profiles of the yields of MGCA obtained in2-propanol media using microwave heating(MW method)and oil-bath heat-ing(OB method)are displayed in Fig.1.Microwave heating in or-ganic synthesis is known to produce products in high yields. Differences in the time profiles of product yields in the synthesis of MGCA under matched temperature conditions were negligible within experimental error.That is,the microwave thermal(caloric) effect(s)followed closely conventional heating to yield nearly80% product after ca.200min.Thus,in this instance,microwaves were a mere source of heat[13],and no microwave specific(non-caloric) effect(s)was evident in the MGCA synthesis taking place in the homogeneous solvent media.Related to this,special(non-caloric) effects of the microwaves in several organic syntheses reported earlier were mostly due to inconsistencies in the temperature mea-surements–see the many examples reported by Stuerga and Gail-lard[8].Accordingly,in the present instance we chose to examine the mechanistic difference(s)between microwave and oil-bath heating from the variance of dielectric factors of the substrates since the heating efficiency of the reaction is controlled by the dielectric factors of the materials contained in the reactor.In the oil-bath heating method,the oil heated the sample initially by thermal conduction through the reactor walls,after which the heat on the inner walls radiated throughout the solution by convection and vigorous mechanical agitation.By contrast,microwave radia-tion penetrated the reactor walls and heated the dielectric substances directly by the dielectric heating mechanism[14,15]. The dielectric constants(e0)and the dielectric loss factors(e00)for pure CP,DMHA,and2-propanol solution were analyzed at the 2.45GHz microwave frequency using an Agilent Technologies HP-85070B Network Analyzer;they are summarized in Table1. The penetration depths of the microwaves into each solution were estimated as suggested by Bogdal[16].The dielectric loss data infer that the CP substrate in the react-ing solution is heated selectively because it displays the highest dielectric loss factor with2-propanol being heated next by dielec-tric heating and by thermal conduction from the heated CP stly,DMHA is heated by thermal conduction by the heat radiated by CP and the2-propanol solvent medium.Note that DMHA occupies a larger volume than CP in the reacting solution. Notwithstanding the differences in the dielectric factors of Table 1,no differences were seen in the product yields(see Fig.1) whether by microwave dielectric heating or by oil-bath heating. Evidently,the characteristics of the microwaves for each molecule did not impact on the reaction since the CP and DMHA substrates dissolved completely in the2-propanol solvent.Sato and Tanaka[17]reported recently that conventional heat-ing of a solid is uneven at the macroscopic level,but is uniform when seen at the microscopic level.By contrast,microwave heat-ing of a solid is uniform at the macroscopic level and uneven atTable1Dielectric constants(e0)and dielectric loss factors(e00)of3-chloro-1,2-propanediol (CP),N,N-dimethylhexadecylamine(DMHA)and2-propanol at a microwave fre-quency of2.45GHz.Dielectricconstant(e0)Dielectric lossfactor(e00)Dielectric losstangent(tan d)Penetrationdepth(cm) CP 6.469 3.6610.566 1.35DMHA 2.4670.1800.07316.92-Propanol 4.586 3.2720.713 1.27S.Horikoshi et al./Chemical Physics Letters491(2010)244–247245the microscopic level.Similar behaviors of heating substrates are expected in solution.In this regard,microwave heating can,in principle,induce localized hot spots that can lead to localized reac-tion rate enhancements[18],and thus to uneven heating at the microscopic level as predicted from the dielectric factors.However, no microwave specific effect(s)was apparent even though the reaction solution contained substrates of different dielectric char-acteristics when heated in homogeneous2-propanol solvent by microwave dielectric heating.It is likely that the2-propanol sol-vent masked whatever specific effect(s)of the microwaves may have been operating.3.2.Synthesis of MGCA under solvent-free conditionsNext we synthesized the MGCA surfactant in a solvent-free het-erogeneous system using the CP and DMHA substrates without2-propanol solvent to avoid its influence in reaction(1).The solution of CP and DMHA was physically mixed by magnetic agitation and appeared as a homogeneous phase when viewed macroscopically. The product yields of MGCA under different conditions,listed in Table2,were otherwise identical at reaction temperatures below 100°C whether by microwave or oil-bath heating methods(reac-tion temperatures,94–96°C;see entries1and2).The boiling points of CP and DMHA are126°C and148°C,respectively[19]. To the extent that the3-chloro-1,2-propanediol(CP)is highly hydrophilic compared to hydrophobic dimethylhexadecylamine (DMHA)it forms self H-bonded aggregates(domains)dispersed in a hydrophobic sea of DMHA molecules,which is reminiscent of an oil-in-water structured emulsion,at least microscopically.A microscopic analysis showed a size distribution of CP domains in the2–20l m range(average size ca.15l m).Viscosity measure-ments showed the CP is16-fold more viscous(0.16Pa s;160cP)than DMHA(0.010Pa s;10cP)at ambient temperature.The viscos-ity of the CP/DMHA mixture decreased with rise in temperature, particularly above100°C.As such,at130°C the yields of MGCA were62%(microwave heating)and47%(oil-bath heating;see en-tries3and4)for the less viscous and uniformly mixed solution after a30-min heating period.The dielectrically heated molecular CP collectives are important in delineating microwave effects.In this regard,note the dramatic shortening of the reaction time(to 6min)displayed by microwave superheating the solution to 185°C yielding48%of the MGCA surfactant(see entry5of Table 2).By contrast,it was not possible to synthesize the surfactant by the oil-bath heating method at the latter temperature.The thermal conduction model portraying the initial stage of the synthesis of the MGCA surfactant at130°C in the absence of the2-propanol solvent is illustrated in Scheme1a for microwave heating and in Scheme1b for oil-bath heating.Macroscopically, the CP and DMHA mixed substrates formed a homogeneous solu-tion upon vigorous magnetic stirring.At the microscopic level, however,it is relevant to emphasize that the solution is heteroge-neous with CP domains(oil drop analogs)dispersed in the DMHA sea.The penetration depths of the microwaves into the CP domains is12.5-fold greater than in DMHA(see Table1),and the dielectric loss factors indicate that the CP aggregates are preferentially heated by the microwaves.Thus,the temperature of the CP do-mains is expected to be greater than the temperature of the DMHA sea.The heat radiated by the CP domains subsequently permeates to the DMHA as a result of thermal gradients established by micro-wave dielectric heating in accordance with the second law of ther-modynamics.After microwave irradiation the distribution of the CP domains in the sea of DMHA molecules tends to become smaller with rise in temperature.The synthesis of the surfactant takes place at the interfaces (reaction sites)between the different CP domains and the DMHA. These interfacial sites are also the sites of heat exchange.A greater number of reaction sites is anticipated under microwave heating (Scheme1a)than is the case in the oil-bath heating model(Scheme 1b)where the molecules are heated non-selectively by the inner reactor walls.In the latter case,thermal conduction throughout the reaction solution depends not so much on the thermal gradi-ents as it does from the vigorous stirring of the solution.The peculiarity of microwave heating,which depends on the dielectric loss tangent,tan d,of each reacting substrate(Table1), can lead to product distributions different from those obtained un-der conventional oil-bath heating(the tan d of CP is7.8-fold greater than that of DMHA).This effect can have a decisive role in hetero-Table2Product yields in the synthesis of monoglycerylcetyldimethylammonium chloride (MGCA)under solvent-free conditions with microwave dielectric heating(MW)and oil-bath heating(OB).Entry Heatingmethod Temperature(°C)Reaction time(min)Product yield(%)1MW9630312OB9430303MW13030624OB13030475MW185648246S.Horikoshi et al./Chemical Physics Letters491(2010)244–247geneous reactions if the domain sizes accorded.Based on the above discussion,the microwave specific effect(s)in a uniformly mixed, albeit heterogeneous system of substrates having greatly different dielectric factors may be operating owing to(i)microscopic tem-perature hot spots produced by penetration of microwaves into the various CP domains,and(ii)to the reaction occurring at the interfacial sites along with heat exchange at these same sites from the high-temperature CP domains to the lower temperature DMHA sea.We saw earlier that the advantage of microwave dielectric heating disappeared when the reaction took place in the2-propa-nol solvent media because the distributions of CP and DMHA do-mains were ill-defined at the molecular level and the reaction was no longer microscopically heterogeneous.Specific effects in organic chemistry have often been discussed on the basis of dielectric factors at the molecular level.The matched size domains may be necessary to make the microwave specific effect(s)obser-vable.Indeed,there may be cases where the influence of micro-waves on molecular domains can bring out specific microwave effects.Other factors can impart specific effects in microwave-assisted reactions.For instance,the wavelength of the2.45-GHz microwaves(k o=12.24cm)can change when the microwaves penetrate a material.It is given by the product of this wavelength (k o)and the velocity of propagation of the microwaves’electric and magneticfields(v)as given by Maxwell’s expression(Eq.(2)) [20]v¼1ffiffiffiffiffiffiffiffiffiffi’l opð2Þwhere e0is the dielectric constant(Table1)and l o is the magnetic permeability(l o%1).For the CP and DMHA substrates the wavelengths of the microwaves decrease to 4.8cm and7.8cm, respectively.This difference in the wavelengths of microwave prop-agation in materials can also lead to microwave specific effects.An examination of the optimal domain size in which the microwave specific effect(s)can be distinguished from thermal effects,perhaps unequivocally,is currently under experimentation.AcknowledgmentsFinancial support to S.H.from the Japan Society for the Promo-tion of Science(JSPS)through a Grant-in-aid for young scientists (No.B-21750210)is gratefully appreciated.One of us(N.S.)thanks Prof.Albini and his group at the Universita di Pavia,Italy,for their continued kind hospitality during the many semesters spent in their laboratory since2002.We are also grateful to the personnel of Hitachi Kyowa Engineering Co.Ltd.and Arios Inc.for technical assistance.References[1]A.Loupy(Ed.),Microwaves in Organic Synthesis,Wiley-VCH Verlag,Weinheim,Germany,2006.[2]L.Perreux,A.Loupy,Tetrahedron57(2001)9199.[3]S.Garbacia,B.Desai,vastre,C.O.Kappe,.Chem.68(2003)9136.[4]S.Horikoshi,N.Ohmori,M.Kajitani,N.Serpone,J.Photochem.Photobiol.A:Chem.189(2007)374.[5]S.Horikoshi,J.Tsuzuki,M.Kajitani,M.Abe,N.Serpone,New J.Chem.32(2008)2257.[6]N.Kuhnert,Angew.Chem.,Int.Ed.41(2002)1863.[7]M.A.Herrero,J.M.Kremsner,C.O.Kappe,.Chem.73(2008)36.[8]D.A.C.Stuerga,P.Gaillard,J.Microwave Power Electromagnet.Energy31(1991)87.[9]D.A.C.Stuerga,P.Gaillard,J.Microwave Power Electromagnet.Energy31(1991)101.[10]S.Horikoshi, F.Sakai,M.Kajitani,M.Abe,N.Serpone,submitted forpublication.[11]S.Horikoshi,J.Tsuzuki,F.Sakai,M.Kajitani,N.Serpone,mun.(2008)4501(see Fig.1S in Supplementary information).[12]K.Tsuchiya,J.Ishikake,T.S.Kimm,T.Ohkubo,H.Sakai,M.Abe,J.Colloid Interf.Sci.312(2007)139.[13]M.Hosseini,N.Stiasni,V.Barbieri,C.O.Kappe,.Chem.72(2007)1417.[14]S.Horikoshi,N.Serpone,J.Photochem.Photobiol.C:Photochem.Rev.10(2009)96.[15]S.Horikoshi,N.Serpone,.Chem.7,in press.[16]D.Bogdal,Tetrahedron Organ.Chem.Ser.25(2005)9.[17]M.Sato,M.Tanaka,Proceedings12th AMPERE Conference,Karlsruhe,Germany,2009.[18]D.Stuerga,P.Gaillard,Tetrahedron52(1996)5505.[19]Data sheets from the reagent manufacturer,Tokyo Chemical Industry Co.Ltd.,Tokyo,Japan.[20]M.Fowler,Maxwell’s Equations and Electromagnetic Waves,PhysicsDepartment,University of Virginia,May9,2009;see<http://galileo.phys./classes/109N/more_stuff/Maxwell_Eq.html>(accessed March 2010).S.Horikoshi et al./Chemical Physics Letters491(2010)244–247247。
微波场非热效应对巴氏杀菌三文鱼脂质品质的影响
微波场非热效应对巴氏杀菌三文鱼脂质品质的影响张 玲1，张 莉2，薛倩倩3，栾东磊1*（1.上海海洋大学 食品学院，上海 201306；2.通标标准技术服务有限公司，山东青岛266101；3.中国海洋大学 食品科学与工程学院，山东青岛 266003）摘 要：为探究三文鱼微波巴氏杀菌过程中非热效应是否存在，采用无线温度传感器记录微波处理过程中三文鱼冷热点的时间温度-曲线后，用水浴加热方式分别对微波冷点和热点进行升温曲线的模拟，从上边界和下边界逼近微波冷热点的时间-温度曲线，即采用双向逼近法研究微波场非热效应。
同时研究了微波场非热效应对三文鱼总脂、过氧化值（Peroxide Value，POV）、硫代巴比妥酸值（Thiobarbituric Acid Reactive Substances，TBARs）、酸价（Acid Value，A V）以及脂肪酸组分的影响。
结果显示，微波处理组总脂肪酸含量显著高于两个水浴处理组，在测得的27种脂肪酸组分中有17种脂肪酸组分的提取系数显著高于两个水浴处理组（P＜0.05）。
研究结果表明，微波加热过程中存在非热效应，使得脂质成分更容易被提取，脂肪酸提取系数增加。
本研究可为微波加热过程中非热效应对食品品质的影响提供理论参考和数据支持。
关键词：三文鱼；微波杀菌；非热效应；双向逼近法；脂肪酸组分The Effect of Microwave Field Non Thermal Effect on the Lipid Quality of Pasteurized SalmonZHANG Ling1, ZHANG Li2, XUE Qianqian3, LUAN Donglei1*(1.College of Food Sciences and Technology, Shanghai Ocean University, Shanghai 201306, China; 2.SGS-CSTC Standard Technical Services, Qingdao 266101, China;3.School of Food Science and Technology, Ocean Universityof China, Qingdao 266003, China)Abstract: To explore the existence of non-thermal effects in the salmon microwave pasteurization, the time-temperature curves of salmon cold and hot spots during microwave processing were recorded with a wireless temperature sensor. Then the time-temperature curves of microwave cold and hot spots were simulated by water bath thermal groups, which were approached from the upper and lower boundaries. The Double sides approximate method studied the non-thermal effects of the microwave field. The effects of microwave field non-thermal effects on salmon total fat, peroxide value (POV), thiobarbituric acid reactive substances (TBARs), acid value (AV) and fatty acid components were studied. The results showed that the total fatty acid content of the microwave groups was not between the two water bath groups and the extraction coefficients of 17 fatty acid components among the 27 fatty acid components measured were higher than the two water bath groups (P＜0.05). The results suggested that the non-thermal effects of the microwave heating made the lipid components easier to be extracted, increasing the fatty acids extraction coefficient. This study provides theoretical reference and data support for the effect of non-thermal effects on food quality during microwave therm al.Keywords:salmon; microwave pasteurization; non-thermal effects; double sides approximate method; fatty acid components基金项目：上海市自然科学基金“微波杀菌处理对软包装秋刀鱼脂质组分的影响机制研究”（20ZR1423800）。
纳米压印
LIGA技術應用產業/產品
• 資訊電子、光電通訊、生化科技、半導體、精 密儀器… • LIGA製程三大技術：X光曝光微影技術、微電 鑄技術、微成形技術。 深刻技術：光源部份 • X光因具有短波長、穿透力強的特性。 • 可提供次微米精度、次微米解析度和高深寬比 的光刻能力。 • 1975年，IBM即開始嘗試。1982年德國卡斯魯 爾核能研究所開發成功。
45~60 0.1 10~40 0.1 12~60 60 10~20
11
Source: ITRI/MIRL
奈米壓印技術介紹 - 前世：LIGA技術
12
何謂LIGA及目的
• LIGA結合了：光刻術(Lithography)、電鍍鑄模技術 (electroforming)，以及微成形之模造(molding)量產技術。 • 所適用的材料範圍包括半導體、金屬、高分子及陶瓷等。 • 可看成傳統機械的模具產業，但尺寸在微奈米。 目的： • 可用於製造高深寬比之微結構。最大可達100的高深寬 比。 • 可製作複雜之3D結構。 • 具較強之結構強度與電、磁致動特性。 • 實現機器縮小化的夢想。
微成形技術(Micro molding) • Micro molding泛指利用模具來進行微結 構的創型或複製。 • 常見Micro molding process包含：
– Hot embossing (熱壓成形) – Nanoimprint (奈米壓印) – Micro injection molding (微射出成形)
31
模仁 脫模 透明基板
LIGA 技術簡介 • 優點 - 可製作高深寬比結構(> 100) - 側壁粗糙度低(數奈米等級) - 高分子材料成本低廉 - 批次生產，高生產速率 - 製程簡單，製造價格低廉 - 適合簡單結構之元件製造，如光學被動元件 • 缺點 - X光之光罩成本高昂，製作費時 - X光之光源價格高昂，不易取得 - 微系統组裝成本高昂 - 缺乏以商業生產為目的之載具 • 瓶頸 - 脫模不易 - 微组裝技術
reference
Home Search Collections Journals About Contact us My IOPscienceFabrication of a microlens array using micro-compression molding with an electroformed mold insertThis article has been downloaded from IOPscience. Please scroll down to see the full text article.2003 J. Micromech. Microeng. 13 98(/0960-1317/13/1/314)View the table of contents for this issue, or go to the journal homepage for moreDownload details:IP Address: 165.91.74.118The article was downloaded on 14/09/2012 at 02:47Please note that terms and conditions apply.I NSTITUTE OF P HYSICS P UBLISHING J OURNAL OF M ICROMECHANICS AND M ICROENGINEERING J.Micromech.Microeng.13(2003)98–103PII:S0960-1317(03)38854-0Fabrication of a microlens array using micro-compression molding with an electroformed mold insertSu-dong Moon1,Namsuk Lee2and Shinill Kang1,21School of Mechanical Engineering,Yonsei University,134Shinchon-dong,Seodaemoon-ku,Seoul,Korea2Center for Information Storage Device,Yonsei University,134Shinchon-dong,Seodaemoon-ku,Seoul,KoreaE-mail:snlkang@yonsei.ac.krReceived1July2002,infinal form17October2002Published4December2002Online at /JMM/13/98AbstractPolymeric microlens arrays,with a diameter of36–96µm,a radius ofcurvature of20–60µm and a pitch of250µm,were fabricated usingmicro-compression molding with electroformed mold inserts.We used thereflow method and the electroforming process to make the mother and themetallic mold inserts,respectively.Micro-compression molding withpowder polymer was developed to replicate microlenses.The surfaceprofiles,imaging qualities,and surface roughness of the microlenses weremeasured and analyzed.1.IntroductionThe increasing demand for micro-optical elements,in the fields of optical data storage,optical communication and digital display,has put mass fabrication technology for polymeric microlens and lens arrays at the forefront of research.Microlenses and microlens arrays can be produced using various methods such as the photoresist reflow method [1–3],etching[4,5],laser ablation[6,7],deposition[8,9]the microjet method[10,11],the photothermal method[12],and micromolding[13–18].Among these,micromolding,including injection molding,compression molding and hot embossing,is regarded as the most suitable mass-production process to replicate microlenses and lens arrays because it offers high repeatability, mass producibility with low cost,and versatility in selecting polymers.Hot embossing developed by Becker and his colleagues uses afilm-type material which is placed on a hot plate in the embossing machine and heated above the glass transition temperature,then pressed to emboss the micro-pattern[14,15].In a previous study,we have developed a micro-compression molding system with a silicon mold insert for a microlens with a diameter of300µm[16,17]. The micro-compression molding system was modified from a conventional macro-compression molding system for micro-size replication.Here,various forms of polymers,such as powders,blocks andfilms,can be used as molded materials.In micromolding processes,micro-mold inserts,which contain the micro-patterns,are required,and the quality of the mold inserts determines the success of whole process.A silicon micro-mold insert is frequently used due to its ease of manufacture.However,a silicon mold insert is too brittle to be used for compression or injection molding for mass production,where high-pressure shock is applied to the mold cavity repeatedly.A metallic mold insert can provide a solution to this problem,and either mechanical machining or electroforming on any micro-patterns can be used to make micro-patterns on the metallic mold insert.However,it is difficult to make patterns of lens shape in a metallic mold insert by mechanical machining if the lens diameter is less than around300µm[18].The main objective of this work is to design and fabricate a microlens array using micro-compression molding with a metallic mold insert.Microlenses,with a diameter of 36–96µm,a radius of curvature of20–60µm and a pitch of250µm,have been fabricated.Figure1shows the procedure for fabricating a microlens array.The reflow method and the electroforming process were used to make the mother and metallic mold inserts,respectively, since mechanical machining could not be applied.Micro-compression molding with powder polymer was used to0960-1317/03/010098+06$30.00©2003IOP Publishing Ltd Printed in the UK98Fabrication of a microlens array using micro-compression molding with an electroformed moldinsertFigure1.The present procedure for fabricating a micro-mold insert for a polymeric microlensarray.Figure2.SEM images of the mother lens array:(a),(c)lens diameter of36µm;(b),(d)lens diameter of96µm.replicate microlenses.Finally,the surface profiles,imaging qualities and surface roughness of the molded lenses were measured and analyzed.2.Fabrication of mother lens by the reflow method To fabricate the microlens by molding,wefirst needed a mother lens of the same shape as thefinal molded lens.Any of the established methods could be used to fabricate the mother lens.The reflow method was used to make mother lens in the present study.The photoresist patterns made by photolithography were thermally treated so that the surface tension converted the patterns into lens form.From the lens shape of desired diameter,height and radius of curvature,we determined the diameter and height of the initial photoresist pattern.Hoechst AZ4620was used as a photoresist material. After spin coating,the desired photoresist patterns were fabricated by photolithography.The photoresist patterns were thermally treated on a hot plate to make the mother lenses. The temperature of the hot plate was160◦C,and the reflow time was60s.Figure2shows scanning electron microscopy (SEM)images of mother lenses with diameters of36and 96µm,respectively.3.Fabrication of nickel mold insert by electroformingAn electron-beam(E-beam)evaporation system was used to deposit the seed layer on the mother lens.Nickel was chosen99S-D Moon et alTable parison of the radius of curvature and sag height of the mother and molded lenses.Mother lens Molded lens Radius of Radius of curvature at Sag height curvature at Sag height E 1(%)E 2(%)Diameter of lens center at center lens center at center =|(R −R m )/R |=|(H −H m )/H |lens (D,µm)(R,µm)(H,µm)(R m ,µm)(H m ,µm)×100×1009659.0625.2458.2925.08 1.300.67644.5323.4643.4423.460.3105631.3821.6131.0221.61 1.1504624.9019.8525.0419.930.560.43619.9517.4919.7517.451.000.2Figure 3.SEM images of the nickel electroformed micro-mold insert:(a )cavity diameter of 36µm;(b )cavity diameter of 96µm.Figure 4.Micro-compression molding system.as the seed layer material because it contains desirable surface properties such as high hardness and thermal stability.Afterthe 1500˚Athick seed layer was deposited,the nickel was mercial nickel sulfamate solution was used as an electrolyte.An electroforming bath consisted of a 66L PVC bath,a power supply,an air pump for agitation,a filter,and a thermostat for temperature control.The bath was maintained at 43–45◦C during electroforming by a current density of 10–20mA cm −2yielding an approximate deposition rate of 1–2µm min −1;the pH value was maintained at 3.8–4.4.We controlled the evaporation and electroforming processes and properly designed the jig to suppress the development of residual stresses in the electroformed layer.After finishing the electroforming,we polished the back side of the electroformed mold insert to obtain the desired mold insert thickness and flatness.After the nickel mold insert was back-polished,the silicon wafer and photoresist were removed.Figure 3shows the SEM images of electroformed nickel mold inserts.The diameters of the concave surfaces were 36and 96µm,respectively,and the pitch of the array was 250µm for both cases.4.Micro-compression moldingMicro-compression molding with powdered optical polymer was used to fabricate a polymeric microlens array.Figure 4shows our micro-compression molding system.The outer cylinder has electrical heating elements for mold heating.A thermocouple and a load cell were placed in the upper ram to measure the mold temperature and pressure histories for the control of temperature and pressure.The mold insert jig was placed on the lower ram and the mold insert was mounted on the jig.The micro-compression molding process is similar to the general molding process.The micro-compression molding process progressed in four stages as follows:(1)Molded material preparation.An optical grade PMMApowder,with a transparency of 93.0%at 3.2mm thickness,a refractive index 1.489at 655nm wavelengths,a haze of 1.0%and a glass transition temperature of 110◦C,was placed on the mold insert.(2)Mold heating and pressing.The compression pressureand molding temperature are governing factors.The mold was heated to a molding temperature that is above the glass transition temperature of PMMA.During heating to molding temperature,pre-pressure was applied to maintain contact between the melting powder and the mold insert.The pre-pressure helps powder to fill the cavity and means that it is heated effectively.Since the powder particles are diffusion-bonded while filling the micro-patterns in micro-compression molding,the molding temperature must be raised to above the100Fabrication of a microlens array using micro-compression molding with an electroformed moldinsertFigure5.SEM images of the molded microlens array:(a),(c)lens diameter of36µm;(b),(d)lens diameter of96µm.parison between the mother and molded lens profiles.glass transition temperature of the polymer.When the temperature of the mold reached the molding temperature, the compression pressure was applied.The molding pressure had to be high enough to improve the replication quality and to give the required bonding force between adjacent polymer particles.However,if the molding temperature and the compression pressure are raised excessively,not only can it deteriorate the mechanical and optical qualities of the molded parts but it can also cause various defects.(3)Cooling and packing.The mold was cooled while thecompression pressure was maintained.A proper cooling rate is important to ensure the quality of the molded lens.(4)Releasing.Once the de-molding temperature had beenreached,the molded microlenses were released from the metallic mold insert.Figure5shows the SEM images of the molded microlens and lens array with diameters of36and96µm,respectively.Figure7.Intensity profile at the focal point of a molded microlens with a diameter of96µm.5.Results and analysis5.1.Replication qualityThe surface profiles of the mother and molded lenses were measured using a three-dimensional(3D)optical profiler, a mechanical profiler,and a scanning electron microscope. The optical interferometric profiler could measure the profile at the top portion of the lens surface with high resolution, but the outer portion of the lens surface could not be measured precisely due to a high tangential angle,whereas the mechanical profiler could notfind the exact center profile101S-D Moon etalFigure 8.AFM images of (a )nickel mold insert and (b )molded lens.The surface roughness (RMS)of the nickel mold insert and molded lens is 0.95and 3.98nm,respectively.of the lens.Therefore,we generated the lens profiles by superposition of mechanical and optical measurements.Table 1shows the diameter,the radius of curvature at the lens center,and the sag height of the mother and the molded lenses.The radius of curvature and the sag height of the molded lenses deviated from those of the mother lenses by less than 0.8µm (1.3%)and 0.2µm (0.6%),respectively.Figure 6shows the comparison between surface profiles of the mother lenses and those of molded lenses with diameters of 36and 96µm,respectively.5.2.Imaging qualitiesThe image spot intensity distribution was measured by a beam profiler using a 665nm laser source.The sample microlens was the molded lens with a diameter of 96µm and a radius of curvature of 58.29µm.The intensity profile at the focal point of the molded microlens is shown in figure 7.The spot diameter with 1/e 2intensity of the peak was 1.386µm.The focal length was measured as 125µm for the molded lens with a diameter of 96µm and a radius of curvature of 58.29µm.5.3.Surface qualityThe surface quality of the mold insert defines the final surface quality of the molded lens.An atomic force microscope (AFM)was used to measure the surface roughness of the mold insert and molded lenses.The specimens were randomly selected to avoid the possibility of a systematic error infiltrating the system.The actual scanned area for each measurement point on the curved surfaces was 5×5µm 2.Figure 8shows AFM images of the cavity surface and the molded surface.The surface roughness (RMS)of the metal mold cavity was 0.95nm,which guarantees a mirror-surface mold cavity.The surface roughness (RMS)of the molded lens was 3.98nm.These measurements show the possibility of using the present molded lens for applications such as data storage and optical communication,in which wavelengths between 405and 850nm are used.This is because the RMS of 3.98nm for the present molded lens is about 0.01λfor high-density optical data storage applications (λ=405nm)and about 0.005λfor optical communications (λ=850nm).6.ConclusionPolymeric microlens arrays,with a diameter of 36–96µm,a radius of curvature of 20–60µm and a pitch of 250µm,were fabricated using micro-compression molding with an electroformed mold insert.The radius of curvature and sag height of the molded lenses deviated from those of the mother lenses by less than 0.8µm (1.3%)and 0.2µm (0.6%),respectively.The spot diameter with 1/e 2intensity of the peak and the focal length,for the molded lens with a diameter of 96µm and a radius of curvature of 58.29µm,were measured as 1.386and 125µm,respectively.The surface roughness (RMS)of the molded lens was 3.98nm.These measurements show the possibility of using the present molded lens for applications such as data storage and optical communications.The application of the present fabrication method to other micro-optical components,including diffractive optical elements,is the subject of ongoing research.AcknowledgmentThis work was funded by the Korea Science and Engineering Foundation through the Center for Information Storage Device (2001G0203)at Yonsei University.References[1]Popovic Z D,Sprague R A and Neville Connell G A 1988Technique for monolithic fabrication of microlens array Appl.Opt.271281–4[2]Lin Y,Pan C,Lin K,Chen S,Yang J and Yang J 2001Polyimide as the pedestal of batch fabricated micro-ball lens and micro-mushroom array Micro Electro Mechanical Systems,200114th IEEE Int.Conf.pp 337–40102Fabrication of a microlens array using 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Photon.Technol.Lett.61112–4[11]Hayes D J and Cox W R1998Micro-jet printing of polymersfor electronics manufacturing Adhesive Joining and coatingTechnology in Electronics Manufacturing pp168–73[12]Borrelli N F,Morse D L,Bellman R H and Morgan W L1985Photolytic technique for producing microlenses inphotosensitive glass Appl.Opt.242520–5[13]Seong K,Moon S and Kang S2001An optimum design ofreplication process to improve optical and geometricalproperties in DVD-RAM substrates J.Inf.StorageProcessing Syst.31–8[14]Ruther P,Gerlach B,Gottert J,Ilie M,Mohr J,Muller A andObmann C1997Fabrication and characterization ofmicrolenses realized by a modified LIGA process PureAppl.Opt.6643–53[15]Moldovan N,Ilie M,Dumbravescu N,Danila M,Vitriuc ASindile P and Mohr J1997LIGA and alternative techniquesfor microoptical components CAS’97Proceedings IEEEpp149–52[16]Moon S,Ahn S,Kang S,Choi D and Je T2001Fabrication of refractive and diffractive plastic micro-opticalcomponents using microcompression molding 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Fabrication of Embedded Microvalve on PMMA Microfluidic Devices through Surface Functionali
9-11 April 2008Fabrication of Embedded Microvalve on PMMA Microfluidic Devices through SurfaceFunctionalizationA. G. G. Toh, Z.F. Wang and S.H. NgSingapore Institute of Manufacturing TechnologyAbstract- The integration of a PDMS membrane within orthogonally placed PMMA microfluidic channels enables the pneumatic actuation of valves within bonded PMMA-PDMS-PMMA multilayer devices. Here, surface functionalization of PMMA substrates via acid catalyzed hydrolysis and air plasma corona treatment were investigated as possible techniques to permanently bond PMMA microfluidic channels to PDMS surfaces. FTIR and water contact angle analysis of functionalized PMMA substrates showed that air plasma corona treatment was most effective in inducing PMMA hydrophilicity. Subsequent fluidic tests showed that air plasma modified and bonded PMMA multilayer devices could withstand fluid pressure at an operational flow rate of 9µL/min. The pneumatic actuation of the embedded PDMS membrane was observed through optical microscopy and an electrical resistance based technique. PDMS membrane actuation occurred at pneumatic pressures of as low as 10kPa and complete valving occurred at 14kPa for ~100µm × 100µm channel cross-sections.I.I NTRODUCTIONMicrofluidic devices offer an attractive route towards the miniaturization of chemical and biological processes in lab-on-chip applications. In these devices, control of micro- to nano-litre fluid volumes in processes such as fluid transport, separation, mixing, and reaction can be achieved through mechanical valving techniques. Traditionally, 3D valve structures are fabricated on silicon-based devices through bulk or surface micromachining methods [1]. Recently, multilayer “soft lithography” methods have been developed to fabricate the microfluidic channels and pneumatic microvalves through replication molding of soft elastomeric materials [2]. The valving is realized through expending the elastomeric membrane into microfluidic channel, which gradually pinches the flow under certain applied air pressures. Polydimethylsiloxane (PDMS) is the popular material choice for replication as it can be easily molded and has a Young’s modulus of ~750 kPa that allows for efficient valving at low actuation pressures [3]. However, such PDMS based multilayer valves suffer from an important drawback: the swelling of PDMS channels after prolonged fluid exposure [4]. The swelling of channels subsequently results in inter-layer misalignment that affects the proper functioning of the entire microfluidic device, especially in microarray devices. In addition, the solvent induced swelling of the material limits the application range of such PDMS devices due to the concern of contamination.As such, rigid thermoplastic polymers such as poly (methyl methacrylate) (PMMA) have been investigated as a possible substrate for the fabrication of microfluidic devices due to their low susceptibility to swelling and biocompatibility [5]. Additionally, open microchannels within PMMA substrates can be rapidly prototyped using high throughput methods such as hot or cold embossing, laser ablation or micro-injection molding. In order to build multilayer embedded valves for lab-on-chip applications, the fabricated PMMA microfluidic substrates must subsequently be bonded to sandwich an elastomeric membrane.Here, we developed a pneumatically active embedded valve capable of actuation at low pressures within a PMMA multi-stacked microfluidic configuration. The principle of valve actuation is based on pressurizing/depressurizing an air chamber that supports a moving elastomeric membrane located below a PMMA fluidic channel (see Figure 1). The valve configuration is designed to accommodate valve arrays within a PMMA-PDMS-PMMA bonded microfluidic network. Low temperature surface functionalization methods such as air plasma and acid hydrolysis treatment were investigated to improve the bonding between the PMMA microfluidic substrates and PDMS based elastomeric thin membrane. In order to examine the valving efficiency, we developed a method for detecting valve efficiency (or channel constriction) based on electrical resistance changes of an electrolyte flowing within microfluidic channels.II.E XPERIMENTALMaterials and chemicalsPoly(methylmethacrylate) (PMMA) sheets of thickness 1.5mm were purchased from Dama Enterprise (Singapore) and cut to circular discs of diameter 101.6mm (~4”) before hot embossing of microfluidic channels. SU-8 3025 negative9-11 April 2008photoresist were purchased from Microchem and used as received. PDMS membranes were fabricated from Slygard 184 silicone elastomer and cure (both purchased from Dow Corning). Sulphuric acid (ACS reagent grade) was obtained from Merck. Electrolytic fluid solution was obtained by diluting 2ml of food dye in 15ml of deionized water (with conductivity of 0.55mS) and subsequently adding 0.5g of Potassium chloride (KCl) salt (purchased from Metrohm). Fabrication of PMMA microfluidic chipsPMMA microfluidic chips were fabricated via hot embossing using a platen hot embossing machine. The hot embossing machine used was a bench-top hydraulic press with a maximum loading of 15 tons. The hydraulic press compressed the embossing tool and substrate between two heated platens. During embossing, the embossing tool and substrate are aligned between the top and bottom platens at room temperature. The platens were subsequently heated above the glass transition temperature (T g) of PMMA. Once the platens were heated to the required temperatures, a pressure of 6MPa was applied for 20mins. The platens were then cooled to 50ºC and the embossed chips were retrieved. The embossed chips were then diced to rectangular pieces of 75mm × 55mm.Prior to hot embossing, the Si/SU-8 embossing tool was fabricated via standard photolithography processes. SU-8 photoresist was spin coated at 1000rpm to yield a thickness of ~100µm. Photolithography of channel patterns on the SU-8 layer was performed using the Karl Suss mask aligner. Pneumatic control channels of a trapezoid cross section were micro-machined using a LPKF circuit board plotter. The base channel width and total channel depth was measured to be ~100 µm and ~250 µm respectively. Markers on both the PMMA embossed chips (fluidic channels) and the machined pneumatic control channels were used to align the substrates during bonding. The entire microfluidic chip fabrication process is summarized in Fig. 1.Fabrication of PDMS membrane valvesThe PDMS elastomer and curing agent were mixed in a 3:1 ratio to yield a PDMS prepolymer solution. The prepolymer was degassed in vacuum for 1 hour before being spin coated on the adhesive layer (see Fig. 1); the adhesive layer had previously been tape rolled onto the PMMA substrate consisting of pneumatic control channels. The PDMS membrane was spun at 1000rpm for 60secs and subsequently degassed again for 1 hour. The PDMS membrane was then completely cured at 65ºC for 3 hours.Surface functionalization of PMMA and PDMS surfacesTwo types of PMMA surface functionalization processes were investigated: acid catalyzed hydrolysis and air corona treatment. During acid catalyzed hydrolysis, PMMA embossed chips were sonicated in 1M of sulphuric acid at 60ºC for 20mins. After removal from the sulphuric acid bath, the PMMA chip was cleaned in deionized water. Plasma treatment of the PMMA chips was performed in air using a corona plasma machine. The plasma treatment was performed for 120 secs at an applied power of 0.5 kW and a frequency of 10 kHz.Fig. 1 Processes involved in fabricating embedded PDMS valves within PMMA microfluidic chips.Characterization of PDMS-PMMA microfluidic chips Dimensional fidelity of Si/SU-8 embossing tools and PMMA embossed chips were measured using a Talyscan mechanical profilometer. PMMA surface functionalization was examined through water contact angle measurements using the VCA Optima XE, which had a measurement accuracy of ±1°. Deionized water was used as the probe liquid in all measurements. The advancing water contact angles presented are an average of 3 measurements.The change in PMMA surface chemistry after surface functionalization was observed using a Bio-Rad Excalibur Fourier transform infrared (FTIR) spectroscope. The FTIR spectra were collected from 64 measurement scans at a resolution of 4cm-1within the wavenumber range of 1000-1800cm-1.III.RESULTS AND DISCUSSIONHot embossing of PMMA substratesIn order to obtain good fidelity between the fabricated Si/SU-8 embossing tool and PMMA substrates, hot embossing of PMMA microfluidic chips was attempted at a temperature range of 95 - 120ºC. This temperature range was investigated based on previously reported T g (~105ºC) values of bulk PMMA substrates.[6, 7] Effective embossing was found to occur at a temperature of 110ºC, an applied pressure of 6 kN/m2(~5 tons of applied mass) and a duration of 20mins. At the aforementioned parameters, profilometric measurements showed that the embossed channels had a dimensional fidelity to the Si/SU-8 embossing tool of greater than 90% (see Fig. 2, 3 and Table 1). While we found that a higher embossing temperature of 120ºC produced PMMA chips with better dimensional fidelity to the embossing tool, a slight warpage of the PMMA substrates was observed upon9-11 April 2008cooling of the platens to 50ºC. An embossing temperature of 110ºC was therefore found to be an effective compromise between dimensional fidelity and substrate flatness.Fig. 2 3D mechanical stylus measurement area of 10mm × 8mm of the (a) Si/SU-8 embossing mold and (b) embossed PMMA microfluidic chip at optimized embossing parameters.y: height of mold or depth of PMMA chipx t : top width x b : bottom widthFig. 3 Channels dimensions measured by mechanical stylus measurementslisted in Table 1.TABLE ID IMENSION COMPARISONS BETWEEN THE SI/SU-8 EMBOSSING TOOL AND PMMAEMBOSSED CHIPS (SAMPLE SIZE: n=3) Sample Temperature(ºC)x t (µm)x b (µm)y (µm)Si/SU-8 embossing tool - 98.2 ± 0.9 94.8 ± 2.1 94.0 ± 1.2 95 78.4 ± 3.1 57.7 ± 4.6 68.4 ± 4.3 100 82 ± 2.7 69.4 ± 2.9 72.3 ± 3.8 110 93.6 ± 2.0 85.0 ± 1.9 87.1 ± 1.9 PMMA embossed chips12096.7 ± 1.686.5 ± 2.491.0 ±2.4Surface functionalization of embossed PMMA chipsThe surface of the embossed PMMA chips was functionalized through two methods: acid catalyzed hydrolysis and air corona plasma treatment. Sulfuric acid catalyzed hydrolysis is considered to be a random process whereby carboxylate or ester terminal groups are catalyzed via the nucleophilic attack of hydroxylic groups. These carboxylate or ester terminal groups are known to subsequently form carboxylic acid groups that render the PMMA surface more hydrophilic than its native state [8]. On the other hand, air plasma treatment of PMMA surfaces is thought to occur due to the radical attack and ozonation of PMMA surface groups [9]. As the gas molecule bombardment of PMMA surfaces is likely to produce a variety of modified surface groups, the process of PMMA hydrophilization via air plasma treatment is less understood. The hydrophilization effects of these treatments could be observed via water contact angle measurements of the modified PMMA surfaces as shown in Fig. 4. The average advancing water contact angle of native unmodified PMMAwas observed to 79.2 ± 5.3º. This value is in agreement to those for unmodified PMMA bulk surfaces reported previously.[8] Acid catalyzed hydrolysis and plasma treatment of the PMMA surface was found to reduce the average advancing water contact angle to 69.8 ± 3.8º and 37.2 ± 2.7º respectively. The surface chemistry modification on the observed PMMA hydrophilization was further analyzed via FTIR spectroscopy.Fig. 4 Surface functionalization of PMMA substrates to aid bonding between the PDMS membrane valve layer to PMMA microfluidic layers. Inset shows the change in advancing water contact angles before and after air plasma and H 2SO 4 acid hydrolysis treatment of PMMA surfaces.FTIR spectroscopic analysis of the treated surfaces indicated that air plasma treatment resulted in larger PMMA surface modifications, hence explaining the greater surface hydrophilization observed (see Fig. 4). It can be seen from Fig. 4 that the C-O peak areas at wavenumber of 1148cm -1 and 1730 cm -1 [5] increased significantly after plasma treatment as compared to acid catalyzed hydrolysis treatment. The increase in C-O surface groups results in an increase in surface electronegativity and polarity, hence increasing its affinity to water. Interestingly, an increase in the number of absorption bands from wavenumber 1350cm -1 to 1800cm -1 was also observed for PMMA substrates that had been plasma treated for 120 secs. This suggests the presence of multiple auxiliary organic groups on the modified PMMA surface, each likely contributing to the surface polarity [8, 9]. It should be noted that an increase in plasma treatment time of up to 300 secs did not result in significant increases in hydrophilization and caused slight warpage and subsequent cracking of the embossed PMMA chips during compression assembly. The increase in PMMA substrate hardness during oxygen air plasma has previously been observed and quantified through nano-indentation experiments [8]. It is likely that air plasma treatment results in the formation of similar oxide and carboxylic species being formed during oxygen plasma treatment. These species have been attributed to the formation of a brittle surface layer on oxygen treated PMMA bulk substrates [8]. Nonetheless, at an air plasma treatment duration of 120 secs, the incorporation of oxides (C-O) and auxiliary aldehydes/organic OH groups to the PMMA surface is expected to improve surface polarity and hence aid bonding between the PDMS membrane and PMMAsubstrate.9-11 April 2008Room temperature bonding of PMMA substratesBonding between surface modified PMMA embossed chips, PDMS membranes and PMMA control channel substrates were performed by room temperature compression (see Fig.1). Effective bonding of the PDMS membrane to plasma treated PMMA embossed chips was achieved at an applied tonnage range of 1.5-2.0 ton (this corresponds to an applied pressure range of 3.57-4.23 MPa for a chip area of 41.25 cm2). At this pressure range, fluid and air flow within the fluid and pneumatic control channels respectively did not exhibit clogging. Furthermore, fluid dye was able to fill the fluidic channels at a flow rate of up to 9 µL/min without any observable leakage.On the contrary, PMMA embossed chips that were functionalized via the acid catalyzed hydrolysis route did not bond well to the PDMS membrane regardless of the applied compression pressure. Additionally, at larger compression pressures of ~7 MPa and above, no effective bonding was achieved and the pressure was found to ‘squeeze’ the membrane into the pneumatic control and fluidic channels as shown in Fig. 5. This suggests that bonding was no longer about physical contact between the PDMS and PMMA surfaces, but physio-chemical interactions between the two surfaces. Here, air plasma corona treatment of the PMMA chip was found to result in better bonding with the PDMS membrane as compared to an acid catalyzed hydrolysis treated chip. We also observed that bonding was not possible without prior air plasma corona treatment.Fig. 5 Micrograph of room temperature compression between PDMS membranes and PMMA substrates at (a) 4.23 MPa (for air plasma corona treated PMMA) and at (b) 7.13 MPa (for acid catalyzed hydrolysis treated PMMA). PDMS microvalve actuationOnce effective bonding between the PDMS membrane layer and PMMA substrates was achieved, the chip was assembled and fitted with inlet/outlet connectors (supplied by Nanoport). Electrical wiring within the inlet/outlet connectors were fitted for electrical resistance sensing of valving efficiency. (see Fig 6(a)) During fluidic tests, top fluidic channels were connected to syringe pumps while bottom pneumatic control channels were connected to compressed air supply (see Fig. 6 (a, b) for microfluidic chip assembly). The “push up” valving mechanism occurring during pressurizing of the pneumatic air control channel is schematically shown in Fig. 6 (c).Fig. 6 (a) Schematic assembly of top PMMA embossed microfluidic chips and, bottom PDMS membrane layer and orthogonally placed PMMA pneumatic channels. (solid arrows indicate fluid inlet/outlets while dotted arrows indicate air inlet/outlets). (b) photo of the final assembled PMMA-PDMS-PMMA microfluidic chip and (c) illustration of PDMS membrane “push up” valve actuation during pressurizing of bottom air channelsThe pneumatic actuation of the PDMS embedded membrane valve was observed through optical microscopy and is shown in Fig. 7. An increase in pneumatic control pressures to 34 kPa resulted in large deflections of the membrane valve, hence resulting in the constriction of fluid flow through the PMMA channel. Normal fluid flow could be resumed when the air chamber pressure was released. The device was able to withstand pressures resulting from the complete valving of fluid flow rates of 1 to 5µL/min, while the complete valving of flows rates greater than 5 µL/min, resulted in flow leakage. Further characterization of these membranes would provide more information on the pressure limitations of both the membrane and device.Fig. 7 Micrograph showing pneumatic control of blue electrolytic fluid dye (at a flow rate of 1µL/min) via a single embedded PDMS based microvalve during (a) no fluid flow, (b)open valving, and valving actuated at (c) P=10kPa, (d) P=14kPa, (e) P=29kPa, and (f) P=34kPa. The top horizontal channel is the PMMA fluid channel while the bottom vertical channel is the pneumatic control line. White arrows in (b) – (f) indicate the location of membrane actuation.While optical visualization of the PDMS membrane movement provided valuable information on valving efficiency, the method proved to be restrictive for field testing of the device. Here, we developed a method to sense valving based on electrical resistance changes in the fluidic channel. Fig. 8 (a) and (b) illustrates the principle behind the electrical9-11 April 2008resistance measurement technique.Fig. 8 (a) Electrical connections for a fluidic channel with a pneumatic channel located above its cross-section and (b) the electrical resistance model used to detect valving when an electrolyte flows through the fluidic channel.Fig. 9 Change in electrical resistance as a function of PDMS membrane valve actuation for various flow rates of electrolytic fluid.When a conductive fluid (electrolyte) is passed through the fluidic channel, a small measurement current can be applied across the channel length to induce a feedback voltage and hence electrical resistance. The fluid volume change in fluidic channel cross sectional area during valving is inversely related to the detected channel resistance (i.e. a decrease in channel cross sectional area results in an increase in channel resistance and vice versa). Fig. 9 shows the increase in resistance during valve actuation at various fluid flow rates. Presently, comparisons with optical micrographs (Fig. 7) show that this detection method can effectively measure complete open and closed valving. As observed from Fig. 9, the electrical resistance increases exponentially as the fluid valve closes; when the PDMS valve was completely closed, the electrical resistance detected increased to a value larger than 200MΩ, which was beyond the detection limit of our ammeter. Although the results show that an increase in valve actuation pressure (and hence channel restriction) results in an increase in detected electrical resistance, the non-linearity of the data suggests that the functional dependence between the two parameters are more complicated. Further experimental work and numerical calculations are needed before the valving states can be accurately mapped from electrical based resistance measurements and vice versa. Similarly, use of an AC power supply is likely to reduce electrical noise that was experienced during the electrical resistance detection under a DC power supply.IV. CONCLUSIONSPMMA microfluidic channels with high fidelity to Si/SU-8 embossing tools were achieved by optimizing the applied embossing temperature within 95 - 120 ºC. The subsequent fabrication of PDMS embedded valves within PMMA substrates was made possible through the oxidation of PMMA surfaces via air plasma corona treatment. Air plasma corona treatment for 120 secs decreased the advancing water contact angles of PMMA surfaces from 79.2 ± 5.3º to 37.2 ± 2.7º. The hydrophilic PMMA substrates were considered to result in an improvement in bonding with the PDMS membrane layer. Subsequent fluid test of the multi-stacked PMMA/PDMS/PMMA device proved that the bond strength achieved was able to withstand fluid flow rates of up to 9 µL/min.The multi-stacked PMMA/PDMS/PMMA device was used to demonstrate the expansion/retraction of PDMS valves within fluidic channels. Actuation of the PDMS valves was achieved at air channel pressures of as low as 10 kPa and complete fluidic channel sealing could be achieved at air pressures of between 14 to 23 kPa. A novel electrical resistance-based detection of valve efficiency successfully monitored the complete open and closed valving states in real-time. The presented solution of such embedded valves has increasing relevance as the need for fluid valving within disposable microfluidic chips (to prevent sample cross contamination) has been well identified for many lab-on-a-chip processes.ACKNOWLEDGMENTThis research is funded by the Agency for Science, Technology and Research (A*STAR), Singapore.REFERENCES[1] O. Geschke, H. Klank and P. Telleman, Microsystem engineering oflab-on-chip devices, Wiley-VCH Verlag: Germany, 2004.[2] M. A. Unger, H-P. Chou, T. Thorsen, A. Scherer and S. R. Quake,“Integrated elastomer fluidic Lab-on-a-chip- Surface patterning andDNA diagnostics”, Science, vol. 288, pp. 113-116, 2000.[3] H-P. Chou et al., “Microfluidic devices and methods of use”, USpatent no. US 7,258,774 B2.[4] J.N. Lee, C. Park and G.M. Whitesides, “Solvent compatibility ofpoly(dimethylsiloxane)-based microfluidic devices”, Anal. Chem.,vol. 75, pp. 6544-6554, 2003.[5] M.V. Risbund, R. Dabhade, S. Gangal and R.R. Bhonde,“Radio-frequency plasma treatment improves the growth andattachment of endothelial cells on poly(methyl methacrylate)substrates: implications in tissue engineering”, J. Biomater. Sci. Pol.Edn., vol 13, pp. 1067-1080, 2002.[6] R. Xing, Z. Wang, Y. Han, “Embossing of polymers using athermosetting polymer mold made by soft lithography”, J. Vac. Sci.Technol. B, vol. 21, pp. 1318- 1322, 2003.[7] P. Nising, T. Zeilmann and T. Meyer, “On the degradation and9-11 April 2008 stabilization of poly(methylmethacrylate) in a continuous process”,Chem. Eng. Technol., vol. 26, pp. 599-604, 2003.[8] L. Brown, T. Koerner, J. H. Horton and R. D. Oleschuk, “Fabricationand characterization of poly(methylmethacrylate) microfluidicdevices bonded using surface modifications and solvents”, Lab onchip, vol. 6, pp. 66-73, 2006.[9] C.W. Tsao, L. Hromada, J. Liu, P. Kumar and D.L. Devoe, …Lowtemperature bonding of PMMA and COC microfluidic substratesusing UV/ozone surface treatment”, Lab on chip, vol. 7, pp. 499-505,2007.。
The use of microcantilevers for sensing
The use of microcantilevers forsensingIntroductionThe sensing of physical and chemical changes is becoming increasingly important in various fields, including industry, healthcare, and environmental monitoring. Scientists and engineers have been searching for new sensing technologies that are sensitive, accurate, reliable, and cost-effective. One emerging technology that shows great potential is the use of microcantilevers for sensing. This article will provide an overview of microcantilevers, their fabrication techniques, and their applications in sensing.Microcantilevers: Definition and PropertiesA microcantilever is a tiny beam, typically made of silicon or other materials, with a length of a few micrometers to several hundreds of micrometers, and a thickness of a few hundred nanometers to several micrometers. Microcantilevers exhibit the following properties that make them attractive for sensing:1. High sensitivity: Microcantilevers can detect the slightest mechanical deformation caused by external forces or surface modifications.2. Low noise: Microcantilevers have high signal-to-noise ratios, due to their small size and low thermal noise.3. Fast response: Microcantilevers can respond quickly to changes in their surroundings, allowing real-time monitoring and analysis.4. Small footprint: Microcantilevers can be integrated into compact and portable sensing devices, suitable for on-site and in-line applications.Fabrication Techniques for MicrocantileversThere are several techniques available for the fabrication of microcantilevers, including:1. Bulk micromachining: A thin silicon wafer is etched using photolithography and anisotropic wet etching to form a suspended microcantilever.2. Surface micromachining: A sequence of deposition, patterning, and etching steps are used to build up a multi-layered microcantilever from a silicon substrate.3. Nanoimprint lithography: A stamp or mold is used to transfer a pattern onto a polymer or resist layer, which is then etched to create a microcantilever.4. Laser machining: A focused laser beam is used to cut, drill, or ablate a solid material to form a microcantilever.Applications of Microcantilevers in SensingMicrocantilevers have been used in various sensing applications, such as:1. Chemical sensing: Microcantilevers coated with sensitive layers can detect the presence and concentration of gases, liquids, and biomolecules. The bending or resonance frequency shifts of microcantilevers are proportional to the amount of analyte adsorbed or reacted on the surface.2. Mechanical sensing: Microcantilevers can detect mechanical stresses, strains, or vibrations caused by external stimuli, such as pressure, temperature, or acoustic waves. The bending or torsional deformation of microcantilevers can be used to measure the magnitude and direction of the applied forces.3. Biological sensing: Microcantilevers modified with biofunctional layers can detect the binding or interaction of biological molecules, such as antigens, antibodies, proteins, and DNA. The recognition events between the immobilized and target molecules can result in changes in the mechanical or electrical properties of the microcantilevers.4. Environmental sensing: Microcantilevers can be used for on-site and in-situ monitoring of pollutants, contaminants, and pathogens in air, water, and soil. Theportable and sensitive microcantilever sensors can provide rapid and accurate measurements in real-world conditions.ConclusionMicrocantilevers are promising sensing devices that offer high sensitivity, low noise, fast response, and small footprint. They can be fabricated using various techniques, and have been applied in chemical, mechanical, biological, and environmental sensing. The development of microcantilever-based sensing technologies can contribute to the advancement of fields such as medicine, food safety, and environmental protection.。
翻译2
7.1Introduction可能是最善意的化学治疗方案几乎没有代表性抽样毫无价值，然而，样品收集和运输上线的仪器，需要非常谨慎，代表性抽样的一些关键因素包括：。
提取样品散装的解决方案，使它代表了实际情况，在这个过程中流体;空调样本，以防止在采样线溶解成分的沉积;保持在一个合适的范围，以防止沉积或夹带的悬浮固体样品的线性速度，进一步空调样品压力和温度，准确的分析Ÿ行工具允许;图7.1和7.2显示采样系统的化学规范实地查看。
虽然抽样的某些方面有突出蜜蜂在前面的章节，下面的讨论提供了一个在这方面蒸汽发电化学更专注的神情。
7.2The需要采样由于许多历史案例说明，可能会发生化学搅得很突然。
除了在非常低的压力单位，研究生本身的抽样是不建议，因为这样只允许化学家获得“快照”的化学条件的意见。
在很大程度上可以发生在干预期间。
适当的化学控制，在线监测几乎已成为必不可少的。
这些分析表7.1通过7.2清单建议的采样点，电力和工业热电联产，蒸汽植物采样参数。
未必是绝对的要求，和这本书的读者可能会说赞成或反对一些分析，或有没有被提及。
然而，计划概述，将使蒸汽发电人员密切监察锅炉条件。
7.3Sample点选择下面的段落解释采样点的选择和分析背后的原因。
首先是一种常见的样本点和参数表中所列的讨论。
7.3.1化妆系统排放废水时，推荐的化妆系统的分析取决于类型的治疗方法。
对于阳离子/阴离子/混床除盐，阴离子的钠，二氧化硅，和电导率的污水分析提供了许多有意义的信息，并可以用来区分阳离子和阴离子的问题。
钠的水平升高表明用尽阴床。
如果阳离子床废气之前，阴床，阴离子污水的导电性会增加。
但是，如果前阴床的排气管排出的废气首先，电导率将DIP前短期内急剧增加。
混床出水的监测是更关键的是，混床是在治疗过程中的最后阶段，任何污染物将直接引入到锅炉给水系统。
典型的分析包括钠，二氧化硅和电导率。
表7.1蒸汽采样点效用鼓锅炉样品推荐点在线分析取样分析频率化妆系统出水钠硅规格分析和建议。
fundamentals-of-microfabrication
fundamentals of microfabrication.pdf FREE PDF DOWNLOADNOWLearn moreInfo for Support Privacy and CookiesAdvertise Help Legal About our ads Feedback © 2014 Microsoft Microfabrication JobsMicrofabrication Plasma Process Microfabrication Lab JHU Microfabrication Facilities 12345Related searches for fundamentals of microfabrication Fundamentals of Microfabrication and … › Books › Education & Reference Now in its third edition, Fundamentals of Microfabrication and Nanotechnology continues to provide the most complete MEMS coverage …Rating: 4.5/5 · 11 reviews · By Marc J. Madou · Hardcover Fundamentals of Microfabrication: The Science of › … › Electronics › Microelectronics Rating: 4.5/5 · 7 reviews Mechanical Engineering: Fundamentals of Microfabrication : The ... Fundamentals of Microfabrication : The Science of Miniaturization. Second Edition.Fundamentals of Microfabrication: The Science of /w/fundamentals-of-microfabrication -marc-j...By Marc J. Madou · Hardcover MEMS technology and applications have grown at a tremendous pace, while structural dimensions have grown smaller and smaller, reaching down even to the molecular ...Fundamentals of microfabrication - Marc J. Madou - Google › … › Electronics › Microelectronics Rating: 5/5 · 1 review Review: Fundamentals of Microfabrication : The Science of Miniaturization User Review - Nathan - Goodreads. Fantastic book on Microfabrication . To say that I've "read ...Product Reviews: Fundamentals of … /Fundamentals -Microfabrication -Science...Rating: 4.5/5 · 11 reviews 5.0 out of 5 stars Fundamentals of Microfabrication This book helps you explore the world of micromachines and miniaturization. First 6 chapters review and explain ...Fundamentals of Microfabrication /~gale/mems/Syllabus%202002%20Utah%20MEMS.pdf · PDF file Fundamentals of Microfabrication BIOEN 6421; ELEN 5221; MEEN 5960 and 6960Class Time: Tuesday and Thursday 2:00-2:50 PM in EMCB 110 Lab sessions to be …Fundamentals of Microfabrication Vol I: Solid-State Physics, Fluidics, and Analytical Techniques in Micro-and Nanotechnology. Vol II: Manufacturing Techniques for Microfabrication and …Fundamentals of Microfabrication and Nanotechnology, Third › … › Nano/Microengineered Devices and Systems Fundamentals of Microfabrication and Nanotechnology, Third Edition, Three-Volume Set - CRC Press Book9780849308260: Fundamentals of Microfabrication : The /9780849308260/Fundamentals -Microfabrication : Fundamentals of Microfabrication : The Science of Miniaturization (9780849308260) by Madou, Marc J. and a great selection of similar New, Used and ...Fundamentals of Microfabrication: The Science of /Fundamentals-of-Microfabrication -The-Science-of...Fundamentals of Microfabrication : The Science of Miniaturization, Second Edition by Marc J Madou - Find this book online from $35.59. Get new, rare & used books at ...Some results have been removedRelated searches Microfabrication Jobs Microfabrication Plasma ProcessMicrofabrication Lab JHUMicrofabrication FacilitiesDefinition of FundamentalFundamental PhysicsFundamental NursingFundamental Synonym。
Advanced Topics in Microbiology
Advanced Topics in MicrobiologyMicrobiology is the study of microorganisms, including bacteria, viruses, fungi, and protozoa. It is a vast and diverse field, and there are many advanced topics within microbiology that are currently being researched and studied. In this article, we will explore some of these advanced topics, including microbial genetics, microbial ecology, and the role of microorganisms in human health and disease.Microbial genetics is a fascinating and rapidly advancing field within microbiology. This area of study focuses on the genetic makeup of microorganisms, including the structure and function of their DNA, RNA, and proteins. Researchers in this field are interested in understanding how genetic variation within microbial populations leads to differences in traits such as antibiotic resistance, virulence, and metabolic capabilities. Understanding microbial genetics is essential for developing new strategies to combat infectious diseases and for developing novel biotechnological applications.Another advanced topic in microbiology is microbial ecology, which is the study of the interactions between microorganisms and their environments. Microbial ecologists investigate how microorganisms colonize and adapt to different environments, such as soil, water, and the human body. They also study the complex webs of interactions between microorganisms and other organisms, including plants, animals, and other microbes. Understanding microbial ecology is crucial for addressing pressing environmental issues, such as climate change, pollution, and the preservation of biodiversity.The role of microorganisms in human health and disease is another important advanced topic in microbiology. While some microorganisms can cause infectious diseases, many others play essential roles in maintaining human health. For example, the human gut microbiota, which consists of billions of bacteria and other microorganisms, has been found to influence human metabolism, immune function, and even behavior. Researchers are also investigating the potential of harnessing the power of beneficial microorganisms to develop new therapies for various diseases, including inflammatory bowel disease, obesity, and even mental health disorders.In addition to the above-mentioned topics, there are many other advanced areas of study within microbiology, such as microbial evolution, virology, and microbial biotechnology. Microbial evolution seeks tounderstand how microorganisms evolve and adapt to changing environmental conditions, including exposure to antibiotics and other stressors. Virology focuses on the study of viruses, which are intracellular parasites that can infect all forms of life. This area of study is particularly relevant given the ongoing threat of emerging viral diseases, such as HIV, Ebola, and Zika. Microbial biotechnology involves the use of microorganisms to produce valuable products, such as pharmaceuticals, biofuels, and industrial enzymes. This field has enormous potential for addressing global challenges related to sustainable energy production, environmental protection, and human health.In conclusion, advanced topics in microbiology encompass a broad range of fascinating and important areas of study, including microbial genetics, microbial ecology, and the role of microorganisms in human health and disease. Understanding these topics is crucial for developing new strategies to combat infectious diseases, addressing environmental challenges, and improving human health and well-being. As technology continues to advance, it is likely that these advanced topics will become even more relevant and impactful in the years to come.。
DESIGN AND HOT EMBOSSING OF MACRO AND MICRO FEATUR
专利名称：DESIGN AND HOT EMBOSSING OF MACRO AND MICRO FEATURES WITH HIGHRESOLUTION MICROSCOPY ACCESS发明人：MAHER, Steven,SAADI, Wajeeh M.,TAYLOR, Amy Jane,SUN, Hoi-Cheong Steve,KYLE,Dennis,ADAMS, John申请号：US2015/036471申请日：20150618公开号：WO2015/195941A1公开日：20151223专利内容由知识产权出版社提供专利附图：摘要：This disclosure provides micro-feature devices and methods for fabricating micro-feature devices. A micro-feature device can include a substantially rigid transparent substrate. The device can include a plurality of macrowells defined in the transparent substrate. Each macrowell can have a width in the range of about one millimeter to about 35 millimeters and a depth in the range of about two millimeters to about 12 millimeters. Each macrowell can include a respective plurality of microwells defined in a respective lower surface of the macrowell. Each microwell can have a width in the range of about 50 microns to about 500 microns and a depth in the range of about 50 microns to about 500 microns.申请人：THE CHARLES STARK DRAPER LABORATORY, INC.,THE UNIVERSITY OF SOUTH FLORIDA地址：555 Technology Square Cambridge, Massachusetts 02139 US,3802 Spectrum Blvd. Suite 100 Tampa, Florida 33512-9220 US国籍：US,US代理人：GORDON, Edward A. et al.更多信息请下载全文后查看。
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Microfabrication by hot embossing and injection molding at LASTIH.Mekaru,T.Yamada,S.Yan,T.Hattorireplication,and can be fabricated nano and micro parts forvarious devices that it is difficult to product by conven-tional machining methods.A key technology which gath-ers mass-production efficiency in the LIGA process ismicro-replication technology.We choiced hot embossingand injection molding methods for replication.For a de-monstration,two kinds of Ni molds,a mesh pattern withina line width of100l m,and an aspect ratio of1.0and amesh pattern within a line width of40l m,and an aspectratio of2.5,were prepared.These were produced withX-ray lithography and nickel electrofoming technique.Inhot embossing,an experiment of micro-replication usingpolymethyl methacrylate(PMMA)and polycarbonate(PC)sheets succeeded.At injection molding,it could nottransfer well with PMMA and PC,but injection tempera-ture was set up highly,and it succeeded by cycloolefinpolymer.Furthermore,we measured sidewall’s surfaceroughness of microstructures produced at each steppes ofthe LIGA process,and it checked that the LIGA processFurthermore,the demand of cheap micro parts made froma plastic is becoming large by chemical,medical andbiological worlds.On the other hand,precise processing ofseveral10-micrometers size cannot do the conventionalmachining technology.The LIGA processes[1]advocatedby the Karlsruhe Nuclear Center(KfK)in Germany in the1980s are the high precise microfabrication technologyusing an X-ray lithography,and mass production tech-nologies which can be carried out by an electroformedmold and replication methods.We conducted basicexperiments of hot embossing and injection moldingmethords as a replication process in the LIGA process.Thepattern of fabricated microstructures chose a mesh patternwith which all the patterns are connected in2-dimensions.Furthermore,sidewall’s surface roughness of the micro-structure produced in each steppes of the LIGA process.Inthis paper,these results are reported.2ratio is produced,the structure within a pattern size ofnanometer-order can be fabricated by hot embossing andinjection molding as put in practical use in fabrication of acompact disk(CD)and a digital video disc(DVD).How-ever,fabrication of precise structures with high aspectratio is difficult.When the deployment to an actualmicrostructure is considered,we must be optimized thereplication condition in a pattern connected in2-dimensions.There are many reports in which fabricationof structures with isolated patterns like a square pillar,or asimplified pattern like a line and space,was successful.However,there are few reports in which fabrication ofstructures with all patterns are connected like a meshpattern,was successful.Microsystem Technologies10(2004)682–688ÓSpringer-Verlag2004DOI10.1007/s00542-004-0401-8Himeji Institute of Technology,3-1-2kamigori,Ako-gun,Hyogo,678–1205,Japane-mail:mekaru@lasti.himeji-tech.ac.jpT.Yamada,S.YanGraduate School of Engineering,Himeji Institute of Technology,2167,Shosya,Himeji,Hyogo671–2201,JapanWe would like to thank Ms.A.Kitajima and Dr.R.Maeda atNational Institute of Advanced Industrial Science and Technology(AIST),Mr.M.Ohtomo at Ikegami Mold Engineering Co.,Ltd.,and Mr.Noriaki Sato at Juken Kogyo Co.,Ltd.for their valuablecollaboration and contributions.This research was the contractresearch from the New Industry Research Organization(NIRO)supportedfinancially by the New Energy and IndustrialTechnology Development Organization(NEDO).6823Experiments and results3.1Preparation of Ni molds with a mesh patternWe prepared two types of Ni molds for a demonstration,a large size pattern of a Ni mold was named mold type I(Ni mold with the pattern of a mesh structure within a line width of200l m,a space width of100l m,and a depth of 200l m),and a more precise pattern size was named mold type II(Ni mold with the pattern of a mesh structure within a line width of40l m,a space width of40l m,and a depth of100l m).The Ni mold was manufactured as follows.The output beam from the beam line BL11for deep X-rays lithography [2]of New SUBARU SR facility[3]was irradiated on1mm-thick polymethyl methacrylate(PMMA)sheet through an X-ray mask with a mesh pattern.The total irradiated energy of dose is3000mA-min.After exposure,the PMMA resist was developed in GG developer,and coated with a nickel sputter layer as an electrode for nickel elec-troforming.In the electroforming process,initial cathode current density was set to1A/dm2,and for approximately 480h.It ground by having made the external surface of a electroforming structure.The current density was gradu-ally raised to5A/dm2.In the last,a Ni electrofoming object were polished,and was made to complete as a Ni mold.Three-dimensional diagram measurement result by the scanning electron microscope(SEM)(S-800,HITACHI Co.,Ltd.)photograph and laser beam microscope(VK-8500,8510,KEYENCE Co.,Ltd.)of each Ni molds are shown in Fig.1(a)and(b),respectively.The size of Ni molds are17·17mm·height of3mm,and the size of a pattern area are17·3mm.3.2Hot embossingThe experiment of hot embossing was conducted using the equipment developed by Maeda Group of the Institute of Mechanical Systems Engineering of the AIST(National Institute of Advanced Industrial Science and Technology) in Japan.The experiment procedure was shown in Fig.3. The Ni mold wasfixed on the upper stage of the equipment (Fig.2(a))and a resin sheet is arranged on the bottom stage of the equipment.(Fig.2(b))Next,after heating the resin sheet and the Ni mold more than the glass transition temperature of the resin.The Ni mold contacted on the surface of the resin sheet by a servomotor drive.The contacting force was applied until it became a setting value,and was hold to press in the resin sheet for several miniutes.(Fig.2(c))Then,after removing load and cooling in air below to glass transition temperature, dembossing was done.The pattern of the Ni mold was transferred on the resin sheet.(Fig.2(d))The experiment of the replication by hot embossing carried out the following parameters,and investigated the optimized condition.First,polycarbonate(PC)and PMMA were chosen as a material of a resin sheet.The glass transition temperature of PC and PMMA are150and 110°C,respectively.PC and PMMA are easy to get as the shape of a sheet.Therefore,we thought PC and PMMA are suitable for this investigation research.Moreover,in order to do easy the dembossing of the Ni mold and the resin sheet,a mold release agent is applied to the surface of the Ni mold pattern.Fluoride and phlorocarbon were chosen as mold release agents.Next,the contacting force which suppresses the Ni mold on the resin sheet,holding time and the heating temperature at the embossing pocess,and the cooling temperature at the dembossing process,were adjusted.Form evaluation of the fabricated patternwasFig.1.SEM images and3D-curvatures measured by Laser Microscope of Ni mold microstructures a the mold type I(Nimold with the pattern of mesh structurewithin a line width of200l m,a spacewidth of100l m,and a depth of200l m),b the mold type II(Ni mold with thepattern of mesh structure within a linewidth of40l m,a space width of40l m,and a depth of100l m)683performed mainly by SEM observation.An example of the evaluation was shown in Fig.3.Fig.3(a)shows mod-ification of the pattern edge portion generated at the dembossing process.Modification arises that the tem-perature at the dembossing process was unsuitable.Moreover,Fig.3(b)is an example to which filling of the resin is not carried out to the whole pattern surface from the reason of which the contacting force and the heating temperature at the embossing process were unsuitable.Based on such form evaluation,the result of optimized replication conditions in hot embossing were summarized in Tables 1and 2.Conditions in Table 1are in case of using the Ni mold type I,and that in Table 2are in case of using the Ni mold type II.The numerical valueswhichFig.2.The experiment procedure of hot embossing,1the Ni mold fixed to the upper stage,2a resin sheet fixed to the bottom stage,3the Ni mold press on the resin sheet,4a sample of the fabricatedreplicationFig.3.Estimation of fabricated replica-tions,a modification of the edge shape of a pattern (upper:good sample,bottom:bad sample),b transferability of a pattern (upper:good sample,bottom:bad sam-ple)684have drawn the underline are optimized conditions.Pho-tographs of SEM image,and 3D diagram by the laser microscope of the pattern fabricated by the optimized condition using the Ni mold type I and II were shown in Fig.4(a)and (b),respectively.The result of these experiments show which microfabrication by hotembossing succeeded in Ni molds of pattern size like type I and II.When the optimized replication conditions in each Ni mold are compared,it turns out clearly that theconditions of the mold release agent and the contacting force differ.The more precise mold pattern in the case of the Ni mold type II,has been required larger contacting force than the Ni mold type I in order to stuff the resin into the pattern.Although phlorocarbon used for the Ni mold type I as a mold release agent was able to carry out coating to the Ni mold by photo-chemical vapor deposition (CVD),coating of a mold release agent will become difficult in case of the the Ni mold with precise patterns like mold type II.Therefore,we have not tried to coat the phlorocarbon on the pattern of the Ni mold type II.Fluoride coating was sprayed on the pattern surface of the Ni mold,and was heated to dry in the furnace.3.3Injection moldingIn the experiment of injection molding,JMW-013S-10t (Juken Machine Works Co.,Ltd.,Japan)injection molding machine was used.A photograph and specifications of this machine are shown in Fig.5(a).The pattern surface of the Ni mold have no coating by a mold release agent using the Ni mold type I and II.The Ni mold has been fixed in the mold base shown in Fig.5(b),and was included in the injection molding machine.In manufacture of this mold base,it was especially cautious of the following points.If the volatilization gas which occurs from internal air and an internal resin material which dissolved is not discharged out of the Ni mold,it will become the cause of defective fabrications.Heat insulation compression is performed quickly.The gas which remained will become as extra-ordinary high temperature,and the resin having referred to this high temperature gas will be disassembled.More-over,a resin may be burned.In consideration of such things,when carrying out the dembossing not only of theTable 1.Replication condition in hot embossing using the Ni mold type I PolymerPolycarbonate (PC)Polymethylmethacrylate (PMMA)Mold release agent F F,Phlorocarbo Contacting force (kN)1,51Holding time (sec)20,6060Embossingtemperature (°C)180140Dembossingtemperature (°C)13095Fig.4.SEM images and 3D-curvatures measured by Laser Microscope of PMMA hot embossing replicated microstructures,a the Ni mold type I (Ni mold with the pattern of mesh structure within a line width of 200l m,a space width of 100l m,and a depth of 200l m),b the mold type II (Ni mold with the pattern of mesh struc-ture within a line width of 40l m,a space width of 40l m,and a depth of 100l m)Table 2.Replication condition in hot embossing using the Ni mold type II PolymerPolycarbonate (PC)Polymethylmethacrylate (PMMA)Mold release agent F F Contacting force (kN)1,51,5Holding time (sec)20,6060Embossingtemperature (°C)180140Dembossingtemperature (°C)13095685usual gas vent slot but the cast to the mold base,it used and projected and the gas omission mechanism was added also to the crevice between a pin or a nest.Experimental results are shown in Tables3and4.Im-portant parameters of injection molding are as follows. resin material,injection temperature,molding tempera-ture,injection pressure,holding pressure,injection speed, injection time,and cooling time.Table3shows the result of this experiment in the case of using the Ni mold type I. Table4is as a result of using the Ni mold type II.Values with underline in tables are optimized conditions and showed photographs of the SEM images,and3D diagrammeasured by the laser microscope of the pattern fabricated on this condition in Fig.6(a)and(b),respectively. Materials for injection molding are chosen PC and PMMA, in order to compare with results of replication experi-ments of hot embossing,and cycloolefin polymer(COP) added in consideration of application to an optical device. Furthermore,the grade of each resin material chose the class which was best in mobility.However,as using PC and PMMA,the Ni mold type I with comparatively large pat-tern size was not able to succeed in perfect fabrication. However,COP was able to be optimized so that clearly from Tables3and4.Since such a situation,the injection molding replication by PC and PMMA was not tried by the Ni mold type II.When the optimal condition in the mold type I and II are compared,the injection temperature differs only.Injection temperature meant the temperature of the melted resin material in a heating cylinder,and it was made to represent with the setting temperature of a heating cylinder for convenience.Although the optimized injection temperature changes with kinds of a resin,as temperature is high,it is better in the mobility of a resin material.However,if temperature is too high,a resin will cause decomposition by heat and the problem which discoloring will occur.As the pattern of a mold becomes precise,the work which separates a replication from a mold becomes more difficult.In the case of the Ni mold type II,it will not succeed in fabrication,if the injection temperature of COP hardly raises by heating below the criticaltemperature.Fig.5.a Injection molding machine and specifications,b mold base of the injec-tion molding machineTable3.Replication condi-tion in injection modling using the Ni mold type I Polymer Polycarbonate(PC)Polymethylmethacrylate(PMMA)Cycloolefin polymer(COP)Injection temperature(°C)310,320,330,340288,300,310258,268,273 Molding temperature(°C)140,150,155,16095,140100,105Injection pressure(MPa)7.0,8.07.07.0Holding pressure(MPa) 6.0,7.2,8.0 6.07.0Injection speed(mm/sec)88,106,128106106Injection time(sec) 2.0 2.0 2.0Cooling time(sec)10.58.510.5Table4.Replication condition in injection molding using the Nimold type IIPolymer Cycloolefin polymer(COP)Injection temperature(°C)273,288,298,308,318,328,338,348Molding temperature(°C)105,110Injection pressure(MPa) 6.0,6.5,7.0,8.0Holding pressure(MPa) 6.0,6.5,7.0,7.5,8.0Injection speed(min/sec)75,88,106,113,118,128Injection time(sec) 2.0Cooling time(sec)10.5686As far as we know,the experiment which succeeded in injection molding fabrication by precise mesh pattern like the Ni mold type II have not been reported.Since the resin sheet heated more than the glass transition temperature is perpendicularly pushed all over a pattern to a mesh pat-tern in hot embossing,if even residents gas can be elimi-nated,it can be imagined that pattern transfer can be carried out easily.However,at injection molding,the resin which dissolved completely enters horizontally to the in-jection gate prepared near the one side of a Ni mold to a mesh pattern,and resin flows into the mesh pattern.When it has solidified before the resin which entered into the pattern at the first spreads round the whole pattern,a resin cannot be poured into a pattern from a gate any more.Filling of a resin progresses as follows.At first,a resin into which it injected from the injection gate is filled up with the parallel slot of the injection direction.Next,another slot of a mesh pattern,a slot perpendicular to the injection direction,is buried.Therefore,in selection of the resin used for injection molding,mobility becomes mostimportant factor.It is expected that injection molding with mesh pattern that spread in 2-dimensions is quite difficult.4Sidewall’s surface roughness of microstructuresThe sidwall’s surface roughness of precise structures in each process of the LIGA process was measured using the laser beam microscope.In order to prevent loss by the penetration of laser light in the case of resin materials,the resin surface was coated by Au-Pd Chemical Vacuum Deposition (CVD).In compared with measured PMMA surface roughness before and after CVD.The surface roughness before CVD wa s 35.6nm,and after that was 33.8nm.Therefore,we judged that deference of the sur-face roughness by Au-Pd CVD could be disregarded.Measured surface roughness of the PMMA resist,the Ni molds,molded products were 34to 120of nm shown in Fig.7,which was a sufficient transferability for practical application using the LIGA process.As compared with the surface roughness (about 500nm)of an ordinary mold fabricated by electrical discharge machine,the surface roughness of the mold fabricated by LIGA process proves very smooth.At the X-ray lithography process,it isespecially less than 35nm with RMS.Yoshimura et al [4]reported that they fabricated Ni mold and molded pro-ducts which the surface roughness was several tens ofnm,Fig.6.SEM images and 3D-curvatures measured by Laser Microscope of COP injection molding replicated micro-structures,a the Ni mold type I (Ni mold with the pattern of mesh structure within a line width of 200l m,a space width of 100l m,and a depth of 200l m),b the mold type II (Ni mold with the pattern of mesh structure within a line width of 40l m,a space width of 40l m,and a depth of 100lm)Measured surface roughness of product’s sidewall in the LIGA process687and if the conditions of a regist development process,and an electroforming and a replication process are optimized, it will be thought that it has suggested that the mass-production accuracy of dozens of nano-order becomes possible.5SummaryThe LIGA process is an integrated process to fabricate micro parts for various devices.We produced the Ni mold type I(Ni mold with the pattern of mesh structure within a line width of200l m,a space width of100l m,and a depth of200l m)and the Ni mold type II with more aggressive pattern size(Ni mold with the pattern of mesh structure within a line width of40l m,a space width of 40l m,and a depth of100l m)by X-ray lithography and electroforming,and carried out the basic experiment by two replication methods as hot embossing and injection ual pattern selected for replication experi-ments in the LIGA process are isolated patterns as dots or line&space patterns.However,a mesh pattern which spread in2-dimensions has not been reported.We selected a mesh pattern to apply to device developments. Experiments using both of Ni mold types succeeded,and larger contacting force need to fabricate structures with more precise pattern by hot embossing.At injection molding,fabrication only by COP succeeded,and it turns out that it is necessary to raise the injection temperature in connection with the mobility of a resin for downsizing of a pattern.In addition,it is thefirst report to have succeeded in replication by injection molding with the precise mesh pattern within a line width of40l m,a space width of 40l m,and a depth of100l m.Moreover,sidewall’s surface roughness of micro-structures produced by LIGA process was measured,the surface roughness of the replication product as the last step of the LIGA process was about100nm,and has checked that the very smooth sidewall’s was acquired as compared with a metallic mold produced by a conven-tional electrical discharge machining technology. 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