这项研究是由国家科学基金会（CMMI模型-0927634）纳米制造程序支持。达沃尔Copic拉克姆优异，在密歇根大学的奖学金计划中的一部分支持。萨迈赫T​​awfick承认拉克姆博士前奖学金的部分支持。迈克尔·的德Volder支持比利时科学研究基金 - 富兰德（FWO）。 Lurie加工设施的（LNF），这是一个国家纳米技术基础设施网络的成员进行微细加工和电子显微镜在密歇根州的电子束分析实验室（EMAL）的执行。

1。催化剂图案<ol><li>获得一个3000A厚的二氧化硅层（100）硅片，抛光边至少有一个。另外，你可能获得一个裸硅片和晶圆上成长3000A二氧化硅。下面描述所有加工完成的晶圆抛光。 </li><li>对于4S 500RPM Spincoat一层HMDS的，然后在30秒3000RPM。 HMDS的提升晶圆与光阻之间的粘连。 </li><li>对于4S 500RPM Spincoat SPR-220-3层，然后在30秒3000RPM。 </li><li> 115°C时为90烤盘上烤的晶圆。 </li><li>所需的口罩，使用催化剂图案的晶圆暴露于紫外线辐射6S硬接触mode.1.6的20毫瓦/平方厘米在405 nm）烘烤晶圆上烤盘，再次在115°为90℃（后曝光烘烤）。 </li><li>使用AZ-300的MIF开发60年代的发展暴露光阻。 </li><li>冲洗纯水60年代的晶圆。 </li><li>其次为1nm铁矿床10nm的AL 2 O 3电子束蒸发或溅射。 </li><li>手工抄写和休息晶圆片约20×20毫米或更小。 </li><li>执行晶圆片浸泡在1L含有丙酮100毫升烧杯光刻胶剥离，烧杯放置在8分钟的超声波浴（翠园超声波1100D）在功率6。 </li><li>处置和替代丙酮和超声再次使用相同的设置。 </li><li>晶圆片传送到与异丙醇（IPA）的烧杯中，然后浸泡2分钟。 </li><li>从"近期行动计划"中删除的晶圆片单独使用镊子。每一块用温和的氮使用手持喷嘴流干燥。 </li></ol> 2。碳纳米管的生长<ol><li>收购裸硅片（或氧化物涂层）和手动划线，并打破了一块尺寸约22×75毫米。这种"船"将用于支持和催化剂涂层的晶圆片，装入管式炉。船装卸过程中的晶圆片是非常有用的，但在成长过程中没有发挥作用。船在原则上可能的任何材料，碳纳米管的生长条件下的化学和热稳定性。 </li><li>将所需数量的催化剂涂层的晶圆片（增长基板）上的船，从​​前沿30毫米。 </li><li>装入增长基板管船。船管等前沿位于下游30mm的炉热电偶，使用不锈钢或石英推杆推入。这30毫米的立场是"甜点"，这给我们的炉碳纳米管的最高增长率。这将是必要的，以确定这个位置上，为用户的设备，根据用户的设备和目标（例如，碳纳米管的增长速度或密度的最大化）。 </li><li>连端盖，密封管。应小心不打扰船或图案的硅块的位置。注:CNT的增长是高度敏感，管内的位置。 </li><li>冲洗与氦1000sccm为5分钟在室温下的石英管。 </li><li>而流动的氢和氦100sccm 400sccm，坡道温度至775°C，10分钟，然后举行的流量和温度为10分钟。这一步会导致化学薄膜，以减少从三氧化二铁铁，到纳米dewet。 </li><li>改变氢气流量100sccm和400sccm氦流率，同时加入100sccm乙烯和保持炉在775°C至成长奈米碳管。这一步的时间控制碳纳米管的高度。 </li><li>停止碳纳米管生长和冷却样品，手动滑动石英管下游，直到催化剂芯片都位于炉中保温约1cm的下游。请小心维持在上一步相同的流量和炉设定温度，15分钟。 </li><li>氦1000sccm冲洗管，5分钟，前提取样品，并关闭炉。 </li></ol> 3。碳纳米管致密化<ol><li>一块双面胶带，适用于厚铝网0.8毫米，与6.25毫米直径孔。确保网格是大于一个1L烧杯中的开放和磁带约网中心。 </li><li>使碳纳米管的微观朝上装入碳纳米管在磁带上的硅晶圆片。 </li><li> 100毫升丙酮倒入1L的烧杯，烧杯放置在通风橱内的热点板块。设置热板表面温度达到110°C等到丙酮开始沸腾。我们注意到，我们的烤盘上，设置了150°C的表面上要求达到110℃。丙酮的沸点低得多（约56℃），但我们傅聪第二，高温丙酮熬更迅速，加热烧杯侧壁，防止烧杯内的凝结。 </li><li>将烧杯等，安装样品朝下铝网。 </li><li>注意:在蒸气方面的任何急剧波动上升烧杯侧面和调整通风柜窗扇稳定蒸气前的水平。 </li><li>一旦蒸汽前面接近烧杯上方，观察在硅衬底表面上明显的颜色变化。彩虹般的模式将会出现，并席卷整个表面。这标志着一个溶剂的薄膜表面上形成时的蒸气接触到冰冷的表面。 </li><li>一旦已存入足够的溶剂，拿起网和样品的方向不改变，举行了从沸点溶剂，直到沉积溶剂蒸发掉。确定的时间量empirically基于碳纳米管结构的大小和间距。这是进一步讨论解决。 </li><li>网格从烧杯中取出，小心剥离的双面胶带样品，用刀片。在这一步，因为它很容易打破拆除过程中的样品，应采取极为谨慎。 </li></ol> 4。碳纳米管硕士模具制造<ol><li>池苏2002年8密度板碳纳米管微观。旋转10秒500RPM样品，然后在30秒3000RPM。 </li><li>在65°C烤2分钟，然后在95℃4分钟Ç样品。 </li><li> 20 75mW/cm 2辐照的样品暴露在紫外线照射下。 </li><li>为2分钟，然后在95°C加热4分钟再烤样品在65°C。 </li></ol> 5。副本成型<ol><li>如果复制脆弱的结构，放置在干燥器随着玻璃的100μL（tridecafluoro-1，1,2,2，tetrahydtoocyl卑鄙的主），三氯在400mTorr 12小时。 </li><li>混合共1G的PDMS（Sylgard 184），与比10:1单体，交联剂。为几微米的基地规模和10个或更多的使用比例为8:1的宽高比与微观结构。 </li><li> CNT的主机放置在一个铝箔菜，倒入菜的PDMS，直到样品被淹没。 </li><li>样品放置在真空和德加在400mTorr 15分钟。一旦泡沫开始形成，在PDMS（通常约3分钟后），定期增加的压力迅速爆大气泡。 </li><li>在120°C固化20分钟负。如果样品中含有的HAR结构，在85°C，治愈时间为5h。 </li><li>一旦固化，剥离背面的铝箔和分离主从柔软的PDMS负手。 </li><li>如果复制脆弱的结构，随着玻璃卑鄙（tridecafluoro-1，1,2,2，tetrahydtoocyl），三氯100μL在干燥器中放置负400mTorr为12H。 </li><li>倒入的PDMS消极和德加在400mTorr 10分钟SU-8 2002年。 </li><li>烘烤样品（SU-8充满负）在65℃为4分钟，然后在95℃反应6h C至溶剂蒸发一层厚厚的SU-8。 </li><li>样品暴露到紫外光辐照20s和烘烤75mW/cm 2再次为4分钟，然后在95°C间为8分钟，在65°C。 </li><li>最后，手动脱模的SU-8负从PDMS副本。 </li></ol> 6。代表结果代表作为土生土长的碳纳米管柱阵列随着致密形状，如图4所示（从德Volder 等修改后的图像。4）。厚度为10μm或更​​小的HAR支柱已逐步减少的直线，这是在致密进一步减少。致密的半圆形柱子已被证明导致大片（图4c），均匀弯曲的支柱。 SU-8我入渗发生之间和内部碳纳米管微观结构，间距为30μm或以下的SU-8可能保持结构之间的薄膜结构。在复制过程中的关键步骤的照片如图5所示，同时比较不同尺度及其复制品复制微观SEM照片如图6所示（Copic 等修改后的图像。5）。电流限制，在结构的形成，包括双绞线结构（修改后的图像从德Volder 等。4），高宽高比墙，和重入结构如图7所示（从Copic 等修改后的图像。5）。 <img src="/files/ftp_upload/3980/3980fig1.jpg" alt="图1" /> 图1。生长碳纳米管的生长炉管安装。 （一）系统原理图。 （二）炉管（热费舍尔Minimite的），盖打开显示硅密封石英管内的船。 （三）硅b燕麦样品，增长之前和之后显示。 <a href="http://www.jove.com/files/ftp_upload/3980/3980fig1large.jpg" target="_blank">点击这里查看大图</a> 。 <img src="/files/ftp_upload/3980/3980fig2.jpg" alt="图2" /> 图2。（一）为控制溶剂蒸汽凝结烧杯设置到碳纳米管的微观结构（从德Volder 等修改后的图像。6）示意图。 （二）CNT样品基板连接到沸腾的丙酮铝网。 <img src="/files/ftp_upload/3980/3980fig3.jpg" alt="图3" /> 图3。副本的碳纳米管微结构的成型，工艺流程和形象代表复制微观阵列相比，美国的四分之一元硬币。 <img src="/files/ftp_upload/3980/3980fig4.jpg" alt="图4" /> 图4。模范碳纳米管微观毛细血管前后Ÿ成形。圆柱形的碳纳米管支柱（a）在毛细血管的形成，和（b）在毛细血管形成（图像修改从德Volder 等。6）阵列的原理和扫描电镜图像。插图显示对齐和密度的碳纳米管。 （三）Semicylindrical CNT的支柱致密成型，形成斜梁（赵等7修改后的图像），在毛细管倾斜。 <a href="http://www.jove.com/files/ftp_upload/3980/3980fig4large.jpg" target="_blank">点击这里查看大图</a> 。 <img src="/files/ftp_upload/3980/3980fig5.jpg" alt="图5" /> 图5。碳纳米管负模具制造和副本铸造的关键步骤。 （一）PDMS负模铸造。 （二）脱气的负面模具。 （三）手动脱模负，和铸造的SU-8的副本。 <img src="/files/ftp_upload/3980/3980fig6.jpg" alt="图6" /> （一）比较图6。<html> CNT/SU-8大师和（二）的副本micropillar结构高保真复制微观尺度的形状和纳米结构（即，侧壁和顶面），显示了大面积（从Copic 等修改后的图像。5）。 <a href="http://www.jove.com/files/ftp_upload/3980/3980fig6large.jpg" target="_blank">单击这里以查看更大的数字</a> 。 <img src="/files/ftp_upload/3980/3980fig7.jpg" alt="图7" /> 图7。高宽比（HAR）的重入碳纳米管微观结构及其聚合物的副本。 （一）:密度板CNT的蜂窝与相应的烘烤固化CNT主站和烘烤固化副本。 （二）硕士和倾斜碳纳米管微孔副本（图片修改从Copic 等。5）。 （三）致密扭曲碳纳米管micropillars主站和个体结构的副本，（修改后的图像从德Volder 等。4）。在蜂窝（一）有墙为400纳米的宽度和高度为20微米。="http://www.jove.com/files/ftp_upload/3980/3980fig7large.jpg"目标="_blank"&gt;点击这里查看大图。

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	<li>Xia, Y. N., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soft+lithography.">Soft lithography.</a> Annual Review of Materials Science. 28, 153-184 (1998).</li><li>Xia, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Replica+molding+using+polymeric+materials:+A+practical+step+toward+nanomanufacturing.">Replica molding using polymeric materials: A practical step toward nanomanufacturing.</a> Advanced Materials. 9, 147-149 (1997).</li><li>Tasis, D., Tagmatarchis, N., Bianco, A., Prato, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemistry+of+Carbon+Nanotubes.">Chemistry of Carbon Nanotubes.</a> Chemical Reviews. 106, 1105-1136 (2006).</li><li>De Volder, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diverse+3D+Microarchitectures+Made+by+Capillary+Forming+of+Carbon+Nanotubes.">Diverse 3D Microarchitectures Made by Capillary Forming of Carbon Nanotubes.</a> Advanced Materials. 22, 4384-4389 (2010).</li><li>Copic, D., Park, S. J., Tawfick, S., De Volder, M. F. L., Hart, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+high-aspect-ratio+polymer+microstructures+and+hierarchical+textures+using+carbon+nanotube+composite+master+molds.">Fabrication of high-aspect-ratio polymer microstructures and hierarchical textures using carbon nanotube composite master molds.</a> Lab on a Chip. 11, 1831-1837 (2011).</li><li>De Volder, M. F. L., Park, S. J., Tawfick, S. H., Vidaud, D. O., Hart, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+and+electrical+integration+of+robust+carbon+nanotube+micropillars+by+self-directed+elastocapillary+densification.">Fabrication and electrical integration of robust carbon nanotube micropillars by self-directed elastocapillary densification.</a> Journal of Micromechanics and Microengineering. 21, 045033-04 (2011).</li><li>Zhao, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bending+of+nanoscale+filament+assemblies+by+elastocapillary+densification.">Bending of nanoscale filament assemblies by elastocapillary densification.</a> Physical Review E. 82, 041605 (2010).</li><li>De Volder, M. F. L., Vidaud, D. O., Meshot, E. R., Tawfick, S., Hart, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-similar+organization+of+arrays+of+individual+carbon+nanotubes+and+carbon+nanotube+micropillars.">Self-similar organization of arrays of individual carbon nanotubes and carbon nanotube micropillars.</a> Microelectronic Engineering. 87, 1233-1238 (2010).</li><li>Nessim, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tuning+of+Vertically-Aligned+Carbon+Nanotube+Diameter+and+Areal+Density+through+Catalyst+Pre-Treatment.">Tuning of Vertically-Aligned Carbon Nanotube Diameter and Areal Density through Catalyst Pre-Treatment.</a> Nano Letters. 8, 3587-3593 (2008).</li><li>Pokroy, B., Epstein, A. K., Persson-Gulda, M. C. M., Aizenberg, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+Bioinspired+Actuated+Nanostructures+with+Arbitrary+Geometry+and+Stiffness.">Fabrication of Bioinspired Actuated Nanostructures with Arbitrary Geometry and Stiffness.</a> Advanced Materials. 21, 463-469 (2009).</li></ol>

没有利益冲突的声明。

平版印刷图案和CNT催化剂基板的准备很简单，重复性好;然而，实现一致的碳纳米管增长需要认真注意的高度和密度的碳纳米管森林环境湿度和增长管条件的影响。在我们的经验，比1000微米模式较大的2不敏感，在加工条件下的小波动。此外，密度的模式了，影响生长密度和高度8。增长的密度和高度较大的填充分数（总面积除以基板面积总量的催化剂）大于约20％的模式。此外，重...

<table border="1"><tbody><tr><td> 试剂名称 </td><td> 公司 </td><td> 目录编号 </td><td> 评论 </td></tr><tr><td> 4"直径&lt;100&gt;硅SiO 2的 （300海里）涂晶圆</td><td>硅任务</td><td>习俗</td><td></td></tr><tr><td>正光阻</td><td> MicroChem </td><td>战略石油储备220-3.0 </td><td></td></tr><tr><td> hexamethyldisilizane （HMDS） </td><td> MicroChem </td><td></td><td></td></tr><tr><td>开发人员</td><td> AZ电子材料美国公司</td><td>排列300的MIF </td><td></td></tr><tr><td>溅射系统</td><td>科特•莱思科</td><td>实验室18 </td><td>催化剂沉积溅射系统</td></tr><tr><td>热费舍尔Minimite的</td><td&gt;尔科技</td><td> TF55030A </td><td>碳纳米管生长炉管</td></tr><tr><td>石英管</td><td>技术玻璃制品</td><td>习俗</td><td> 22毫米内径×25毫米外径30"的长度</td></tr><tr><td>氦气</td><td> PurityPlus </td><td>他（PrePurified 300） </td><td></td></tr><tr><td>氢气</td><td> PurityPlus </td><td> H2（PrePurified 300） </td><td>超高压</td></tr><tr><td>乙烯气体</td><td> PurityPlus </td><td> C 2 4（PrePurified 300） </td><td>超高压</td></tr><tr><td>穿孔铝板</td><td>麦克马斯特，卡尔</td><td> 9232T221 </td><td>举行样品致密烧杯以上</td></tr><tr><td>紫外线泛光灯</td><td> DYMAX </td><td> 2000型</td><td></td></tr><tr><td>苏-8 2002年</td><td> MicroChem </td><td>苏-8 2002年</td><td></td></tr><tr><td>聚二甲基硅氧烷 （PDMS）中</td><td>道康宁</td><td> sylgard 184硅橡胶套件</td><td></td></tr></tbody></table>

fabrication, densification, and replica molding of 3d carbon nanotube microstructures

微细新材料和新工艺的引进，很大一部分在微系统，实验室的单芯片器件及其应用，使许多重要的进展。软光刻技术和其他技术micromolding 1，2的到来，特别是聚合物微观结构具有成本效益的制造能力转化，这导致在微细生物医学工程和生物应用的革命。尽管如此，它仍然是挑战，以编造的微观结构，具有定义良好的纳米级表面纹理和制作，在微观尺度的任意三维形状。主模具和形状的完整性维护的鲁棒性，尤其重要的是实现复杂结构的高保真复制和维护他们的纳米表面纹理。现有的微细加工方法结合分层纹理，异构的形状，是一场深刻的挑战，LARgely依靠自上而下使用固定不变的面具模板蚀刻后。另一方面，自下而上的纳米管和纳米线等纳米结构的合成，可以提供新的功能，微细加工，尤其是通过利用纳米结构的自组织的集体，局部控制其生长行为的微模式。 我们的目标是引入垂直排列的碳纳米管（CNTs），我们是指作为一种新的微细加工材料，碳纳米管的"森林"。我们提出了一套最近由本集团开发的相关方法的详细资料:热化学气相沉积法制备碳纳米管森林显微光刻图案催化剂薄膜;自我导向的碳纳米管微结构的elastocapillary致密;和副本成型聚合物的微观结构，使用碳纳米管复合主模具。特别是，我们的工作表明，自我导向的毛细血管致密化（"毛细形成"），这是射孔碳纳米管微结构的衬底上rmed溶剂冷凝，显着提高了碳纳米管的堆积密度。此过程可分为直，斜，扭曲的形状，有强大的超过典型微细聚合物的机械属性的垂直碳纳米管微结构的转型。这反过来又使毛细血管渗透驱动的聚合物形成碳纳米管纳米复合材料主模具。副本结构表现出的奈米碳管的各向异性纳米质地，并能与亚微米厚的墙和纵横比超过50:1。在制造碳纳米管微结构的整合提供了更多的机会，利用碳纳米管的导电性和导热性能，多样的功能，化学和生化官能3。

Watch this Scientific Journal Video about Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures at JoVE.com

Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures

我们提出的垂直排列的碳纳米管（CNTs），并利用其作为主模具生产聚合物微观结构与有组织的纳米表面纹理图案的微观结构的制造方法。基板上凝结的溶剂，这大大增加了他们的堆积密度，使自我导向形成三维形状的碳纳米管森林致密。

制备，致密，副本三维碳纳米管微结构成型

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip ...

fabrication-densification-replica-molding-3d-carbon-nanotube

Research

JoVE Journal

Engineering

20.0K 次观看.  University of Michigan. 我们提出的垂直排列的碳纳米管（CNTs），并利用其作为主模具生产聚合物微观结构与有组织的纳米表面纹理图案的微观结构的制造方法。基板上凝结的溶剂，这大大增加了他们的堆积密度，使自我导向形成三维形状的碳纳米管森林致密。

视频: Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures

Process of Making Three-dimensional Microstructures using Vaporization of a Sacrificial Component

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material fabrication techniques are able to mimic the complexity of these structures while maintaining scalability. The Vaporization of a Sacrificial Component (VaSC) process is able to do so. This process uses sacrificial fibers as a template to form hollow, cylindrical microchannels embedded within a matrix. Tin (II) oxalate (SnOx) is embedded within poly(lactic) acid (PLA) fibers which facilitates the use of this process. The SnOx catalyzes the depolymerization of the PLA fibers at lower temperatures. The lactic acid monomers are gaseous at these temperatures and can be removed from the embedded matrix at temperatures that do not damage the matrix. Here we show a method for aligning these fibers using micromachined plates and a tensioning device to create complex patterns of three-dimensionally arrayed microchannels. The process allows the exploration of virtually any arrangement of fiber topologies and structures.

The Vaporization of a Sacrificial Component (VaSC) process is used to fabricate microvascular structures. This procedure uses sacrificial poly(lactic) acid fibers to form hollow microchannels with precise 3D geometric positioning provided by laser micromachined guide plates.

制作三维微结构，用牺牲部分汽化过程

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material ...

科研

工程学

Manufacturing of Three-dimensionally Microstructured Nanocomposites through Microfluidic Infiltration

Microstructured composite beams reinforced with complex three-dimensionally (3D) patterned nanocomposite microfilaments are fabricated via nanocomposite in&#64257;ltration of 3D interconnected microfluidic networks. The manufacturing of the reinforced beams begins with the fabrication of microfluidic networks, which involves layer-by-layer deposition of fugitive ink filaments using a dispensing robot, filling the empty space between filaments using a low viscosity resin, curing the resin and finally removing the ink.&#160;Self-supported 3D structures with other geometries and many layers (e.g.&#160;a few hundreds layers) could be built using this method. The resulting tubular micro&#64258;uidic networks are then infiltrated with thermosetting nanocomposite suspensions containing nanofillers (e.g.&#160;single-walled carbon nanotubes), and subsequently cured. The infiltration is done by applying a pressure gradient between two ends of the empty network (either by applying a vacuum or vacuum-assisted microinjection). Prior to the infiltration, the nanocomposite suspensions are prepared by dispersing nanofillers into polymer matrices using ultrasonication and three-roll mixing methods. The nanocomposites (i.e.&#160;materials infiltrated) are then solidified under UV exposure/heat cure, resulting in a 3D-reinforced composite structure. The technique presented here enables the design of functional nanocomposite macroscopic products for microengineering applications such as actuators and sensors.

Three-dimensional (3D) microstructured composite beams are fabricated through the directed and localized infiltration of nanocomposites into 3D porous microfluidic networks. The flexibility of this manufacturing method enables the utilization of different thermosetting materials and nanofillers in order to achieve a variety of functional 3D reinforced nanocomposite macroscopic products.

通过微流体渗透制备三维微结构纳米复合材料的制造

Microstructured composite beams reinforced with complex three-dimensionally (3D) patterned nanocomposite microfilaments are fabricated via nanocomposite ...

化学

Novel 3D/VR Interactive Environment for MD Simulations, Visualization and Analysis

The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials science, biology, chemistry and physics among many others. A new computational system for the accurate and fast simulation and 3D/VR visualization of nanostructures is presented here, using the open-source molecular dynamics (MD) computer program LAMMPS. This alternative computational method uses modern graphics processors, NVIDIA CUDA technology and specialized scientific codes to overcome processing speed barriers common to traditional computing methods. In conjunction with a virtual reality system used to model materials, this enhancement allows the addition of accelerated MD simulation capability. The motivation is to provide a novel research environment which simultaneously allows visualization, simulation, modeling and analysis. The research goal is to investigate the structure and properties of inorganic nanostructures (e.g., silica glass nanosprings) under different conditions using this innovative computational system. The work presented outlines a description of the 3D/VR Visualization System and basic components, an overview of important considerations such as the physical environment, details on the setup and use of the novel system, a general procedure for the accelerated MD enhancement, technical information, and relevant remarks. The impact of this work is the creation of a unique computational system combining nanoscale materials simulation, visualization and interactivity in a virtual environment, which is both a research and teaching instrument at UC Merced.

A new computational system featuring GPU-accelerated molecular dynamics simulation and 3D/VR visualization, analysis and manipulation of nanostructures has been implemented, representing a novel approach to advance materials research and promote innovative investigation and alternative methods to learn about material structures with dimensions invisible to the human eye.

新颖的3D / VR互动环境MD模拟，可视化和分析

The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials ...

Prescribed 3-D Direct Writing of Suspended Micron/Sub-micron Scale Fiber Structures via a Robotic Dispensing System

A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer fiber length and orientation is defined by the spatial positioning of the dispensing system 3-axis stages. The fiber diameter is defined by the prescribed dispense time of the dispensing system valve, the feed rate (the speed at which the stage traverses from an initiating to a terminating position), the gauge diameter of the dispensing tip, the viscosity and surface tension of the polymer solution, and the programmed drawing length. The stage feed rate affects the polymer solution&#8217;s evaporation rate and capillary breakup of the filaments. The dispensing system consists of a pneumatic valve controller, a droplet-dispensing valve and a dispensing tip. Characterization of the direct write process to determine the optimum combination of factors leads to repeatedly acquiring the desired range of fiber diameters. The advantage of this robotic dispensing system is the ease of obtaining a precise range of micron/sub-micron fibers onto a desired, programmed location via automated process control. Here, the discussed self-assembled micron/sub-micron scale 3D structures have been employed to fabricate suspended structures to create micron/sub-micron fluidic devices and bioengineered scaffolds.

Here, we present a protocol to fabricate freely-suspended, micron/sub-micron scale polymer fibers and &#8220;web-like&#8221; structures generated via automated direct writing procedure by means of a 3-axis dispensing system.

暂停规定微米/亚微米尺度的纤维结构的3-D直写经全自动点胶系统

A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer ...

Fabrication of Low Temperature Carbon Nanotube Vertical Interconnects Compatible with Semiconductor Technology

We demonstrate a method for the low temperature growth (350 &#176;C) of vertically-aligned carbon nanotubes (CNT) bundles on electrically conductive thin-films. Due to the low growth temperature, the process allows integration with modern low-&#954; dielectrics and some flexible substrates. The process is compatible with standard semiconductor fabrication, and a method for the fabrication of electrical 4-point probe test structures for vertical interconnect test structures is presented. Using scanning electron microscopy the morphology of the CNT bundles is investigated, which demonstrates vertical alignment of the CNT and can be used to tune the CNT growth time. With Raman spectroscopy the crystallinity of the CNT is investigated. It was found that the CNT have many defects, due to the low growth temperature. The electrical current-voltage measurements of the test vertical interconnects displays a linear response, indicating good ohmic contact was achieved between the CNT bundle and the top and bottom metal electrodes. The obtained resistivities of the CNT bundle are among the average values in the literature, while a record-low CNT growth temperature was used.

A method for the growth of low temperature vertically-aligned carbon nanotubes, and the subsequent fabrication of vertical interconnect electrical test structures using semiconductor fabrication is presented.

低温碳纳米管垂直互连的制作兼容半导体技术

We demonstrate a method for the low temperature growth (350 &#176;C) of vertically-aligned carbon nanotubes (CNT) bundles on electrically conductive ...

Fabrication of the Thermoplastic Microfluidic Channels

In our lab, we have successfully isolated nucleic acids directly from microliter and submicroliter volumes of human blood, urine and stool using polymer/nanoparticle composite microscale lysis and solid phase extraction columns. The recovered samples are concentrated, small volume samples that are PCRable, without any additional cleanup. Here, we demonstrate how to fabricate thermoplastic microfluidic chips using hot embossing and heat sealing. Then, we demonstrate how to use in situ light directed surface grafting and polymerization through the sealed chip to form the composite solid phase columns. We demonstrate grafting and polymerization of a carbon nanotube/polymer composite column for bacterial cell lysis. We then show the lysis process followed by solid phase extraction of nucleic acids from the sample on chip using a silica/polymer composite column. The attached protocols contain detailed instructions on how to make both lysis and solid phase extraction columns.

Here we demonstrate how to fabricate thermoplastic microfluidic chips using hot embossing and heat sealing. Then we demonstrate how to use in situ light directed surface grafting and polymerization through the sealed chip to form the composite solid phase columns.

制备热塑性微流体通道

In our lab, we have successfully isolated nucleic acids directly from microliter and submicroliter volumes of human blood, urine and stool using ...

生物学

Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell cultivation. These technologies offer a wide spectrum of advantages not only for manufacturing but also for different applications. The size and shape of formed cell clusters can be influenced by the exact and reproducible architecture of the microfabricated scaffold and, therefore, the diffusion path length of nutrients and gases can be controlled.1 This is unquestionably a useful tool to prevent apoptosis and necrosis of cells due to an insufficient nutrient and gas supply or removal of cellular metabolites.
Our polymer chip, called CellChip, has the outer dimensions of 2 x 2 cm with a central microstructured area. This area is subdivided into an array of up to 1156 microcontainers with a typical dimension of 300 m edge length for the cubic design (cp- or cf-chip) or of 300 m diameter and depth for the round design (r-chip).2
So far, hot embossing or micro injection moulding (in combination with subsequent laborious machining of the parts) was used for the fabrication of the microstructured chips. Basically, micro injection moulding is one of the only polymer based replication techniques that, up to now, is capable for mass production of polymer microstructures.3 However, both techniques have certain unwanted limitations due to the processing of a viscous polymer melt with the generation of very thin walls or integrated through holes. In case of the CellChip, thin bottom layers are necessary to perforate the polymer and provide small pores of defined size to supply cells with culture medium e.g. by microfluidic perfusion of the containers.
In order to overcome these limitations and to reduce the manufacturing costs we have developed a new microtechnical approach on the basis of a down-scaled thermoforming process. For the manufacturing of highly porous and thin walled polymer chips, we use a combination of heavy ion irradiation, microthermoforming and track etching. In this so called "SMART" process (Substrate Modification And Replication by Thermoforming) thin polymer films are irradiated with energetic heavy projectiles of several hundred MeV introducing so-called "latent tracks" Subsequently, the film in a rubber elastic state is formed into three dimensional parts without modifying or annealing the tracks. After the forming process, selective chemical etching finally converts the tracks into cylindrical pores of adjustable diameter.

We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.

芯片尺寸支架的三维细胞培养的微细

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell ...

Precision Milling of Carbon Nanotube Forests Using Low Pressure Scanning Electron Microscopy

A nanoscale fabrication technique appropriate for milling carbon nanotube (CNT) forests is described. The technique utilizes an environmental scanning electron microscope (ESEM) operating with a low pressure water vapor ambient. In this technique, a portion of the electron beam interacts with the water vapor in the vicinity of the CNT sample, dissociating the water molecules into hydroxyl radicals and other species by radiolysis. The remainder of the electron beam interacts with the CNT forest sample, making it susceptible to oxidation from the chemical products of radiolysis. This technique may be used to trim a selected region of an individual CNT, or it may be used to remove hundreds of cubic microns of material by adjusting ESEM parameters. The machining resolution is similar to the imaging resolution of the ESEM itself. The technique produces only small quantities of carbon residue along the boundaries of the cutting zone, with minimal effect on the native structural morphology of the CNT forest.

Low pressure scanning electron microscopy in a water vapor ambient is used to machine nanoscale to microscale features in carbon nanotube forests.

碳纳米管森林精密铣床使用低压扫描电子显微镜

A nanoscale fabrication technique appropriate for milling carbon nanotube (CNT) forests is described. The technique utilizes an environmental scanning ...

Fabrication of 3D Carbon Microelectromechanical Systems (C-MEMS)

A wide range of carbon sources are available in nature, with a variety of micro-/nanostructure configurations. Here, a novel technique to fabricate long and hollow glassy carbon microfibers derived from human hairs is introduced. The long and hollow carbon structures were made by the pyrolysis of human hair at 900 &#176;C in a N2 atmosphere. The morphology and chemical composition of natural and pyrolyzed human hairs were investigated using scanning electron microscopy (SEM) and electron-dispersive X-ray spectroscopy (EDX), respectively, to estimate the physical and chemical changes due to pyrolysis. Raman spectroscopy was used to confirm the glassy nature of the carbon microstructures. Pyrolyzed hair carbon was introduced to modify screen-printed carbon electrodes ; the modified electrodes were then applied to the electrochemical sensing of dopamine and ascorbic acid. Sensing performance of the modified sensors was improved as compared to the unmodified sensors. To obtain the desired carbon structure design, carbon micro-/nanoelectromechanical system (C-MEMS/C-NEMS) technology was developed. The most common C-MEMS/C-NEMS fabrication process consists of two steps: (i) the patterning of a carbon-rich base material, such as a photosensitive polymer, using photolithography; and (ii) carbonization through the pyrolysis of the patterned polymer in an oxygen-free environment. The C-MEMS/NEMS process has been widely used to develop microelectronic devices for various applications, including in micro-batteries, supercapacitors, glucose sensors, gas sensors, fuel cells, and triboelectric nanogenerators. Here, recent developments of a high-aspect ratio solid and hollow carbon microstructures with SU8 photoresists are discussed. The structural shrinkage during pyrolysis was investigated using confocal microscopy and SEM. Raman spectroscopy was used to confirm the crystallinity of the structure, and the atomic percentage of the elements present in the material before and after pyrolysis was measured using EDX.

Fabrication of 3D Carbon Microelectromechanical Systems C-MEMS

Long and hollow glassy carbon microfibers were fabricated based on the pyrolysis of a natural product, human hair. The two fabrication steps of carbon microelectromechanical and carbon nanoelectromechanical systems, or C-MEMS and C-NEMS, are: (i) photolithography of a carbon-rich polymer precursor and (ii) pyrolysis of the patterned polymer precursor.

3D碳微机电系统（C-MEMS）的制造

A wide range of carbon sources are available in nature, with a variety of micro-/nanostructure configurations. Here, a novel technique to fabricate long ...

Fabrication of Three-Dimensional Graphene-Based Polyhedrons via Origami-Like Self-Folding

The assembly of two-dimensional (2D) graphene into three-dimensional (3D) polyhedral structures while preserving the graphene's excellent inherent properties has been of great interest for the development of novel device applications. Here, fabrication of 3D, microscale, hollow polyhedrons (cubes) consisting of a few layers of 2D graphene or graphene oxide sheets via an origami-like self-folding process is described. This method involves the use of polymer frames and hinges, and aluminum oxide/chromium protection layers that reduce tensile, spatial, and surface tension stresses on the graphene-based membranes when the 2D nets are transformed into 3D cubes. The process offers control of the size and shape of the structures as well as parallel production. In addition, this approach allows the creation of surface modifications by metal patterning on each face of the 3D cubes. Raman spectroscopy studies show the method allows the preservation of the intrinsic properties of the graphene-based membranes, demonstrating the robustness of our method.