Name: micro-masonry for 3d additive micromanufacturing
Uploaded: 2014-08-01T15:00:00.000+00:00
Duration: 8 min 45 s
Description: Watch this Scientific Journal Video about Micro-masonry for 3D Additive Micromanufacturing at JoVE.com

This work was supported by the NSF (CMMI-1351370).

1，设计面膜供体基板的制作<ol><li>设计具有所需几何形状的面具。为了制作100微米×100微米见方的硅个别单位，画出100微米×100微米的正方形阵列。 </li><li>设计第二掩模具有相同的几何形状，与各侧延伸出额外的15微米。为100微米×100微米的正方形阵列，绘制的130微米×130微米的正方形可以覆盖的平方在步骤1.1的阵列。 </li><li>设计锚几何。得出4个20微米×40微米的矩形，每个沿着正方形的一边为中心。放置的结构，使得第一15μm的覆盖原来的100微米×100微米的正方形，在步骤1.1和向外剩余的25微米的延伸（ 如图2）。 注意:任何形状和尺寸可以作为长期被用作锚接点的图案化的材料和基片。这种锚的一端覆盖的起源在步骤1.1，将另一端几何人应该延伸出的几何形状，在步骤1.2。 </li></ol> 2，准备打捞供体基板<ol><li>准备上绝缘体（SOI）晶片的p型掺杂的硅用3微米的器件层的厚度，具有1-20Ω•厘米和框氧化物层的1微米厚的薄层电阻。注:对于不同的应用中，这些参数都可以修改。 </li><li>旋涂光致抗蚀剂（AZ5214，3000 rpm离心30秒，1.5微米厚），并附加设计步骤1.1掩模。 </li><li>使用反应离子刻蚀（RIE）的仪器，图案的SOI晶片的器件层和除去光致抗蚀剂掩模。在此步骤之后，在RIE腐蚀区域暴露的框中氧化物层（ 图2A）。 </li><li>旋涂光致抗蚀剂（AZ5214，3000 rpm离心30秒，1.5μm厚）和图案掩模设计步骤1.2。 </li><li>加热晶片，在125℃下进行90秒的热板上。 </li><li>沉浸在晶圆成49％的HF，50秒蚀刻步骤2.3暴露箱的氧化层。经过彻底的干燥，去除光致抗蚀剂掩模（ 图2B）。 </li><li>旋涂（AZ5214，3000 rpm离心30秒，1.5μm厚）和图案从步骤1.3锚固设计。 </li><li>加热晶片，在125℃下进行90秒的热板上。 </li><li>浸入49％的HF 50分钟。这一步刻蚀余下的剩余图案的器件层的硅下面的框中的氧化层，从而导致光致抗蚀剂（ 图2C）悬浮硅个别单元。 </li></ol> 3，设计面膜微尖邮票<ol><li>设计一个面具一个100微米×100微米的正方形。 </li><li>设计一个面具多12微米×12微米，100微米×100微米区域内的广场。 </li></ol> 4，使模具的微尖邮票<ol><li>清洁硅晶片上的&lt;1-0-0&gt;晶向，DEPO利用等离子体增强化学气相沉积（PECVD）设备坐氮化硅为100nm。 </li><li>旋涂光致抗蚀剂（AZ5214，3000 rpm离心30秒，1.5μm厚）和图案掩模设计步骤3.2。 </li><li>图案用10:1缓冲氧化蚀刻剂（BOE）的氮化硅层。 </li><li> 170毫升去离子水和40ml异丙醇（IPA）混合物的烧杯中的溶解将80克氢氧化钾（KOH）。 </li><li>在80℃下加热的KOH，IPA和水的混合物在热板上。 </li><li>垂直放置准备好的晶片在烧杯中，用KOH的混合物以蚀刻露出的硅中的晶体结构（蚀刻率大约是1微米/分钟）。 </li><li>后暴露的硅被完全蚀刻时，从氢氧化钾混合物取出晶片，使用HF刻蚀掉氮化硅，并执行RCA 1和RCA清洗2（ 图3A）。 </li><li>旋涂以SU-8 100和模式与步骤3.1准备的面具下面的配方:3,000Ř时，持续1分钟，软烘烤，在65℃10分钟，95℃30分钟，暴露与550毫焦耳/厘米2，和后烘烤在65℃下1分钟，95℃，10分钟（ 图3B中 ）。 </li><li>后的SU-8 100完全固化，适用的（十三氟-1，1,2,3 - 四氢辛基）-1 - 三氯硅烷的单层滴加3-5滴（十三氟-1，1,2,3 - 四氢辛基）-1-三氯成真空罐，并放置在晶圆的jar和应用真空。 </li></ol> 5，重复微尖邮票使用模具<ol><li>混合聚二甲基硅氧烷（PDMS）基料和固化剂以5:1的比例。 </li><li>通过将其放置在真空罐脱气混合物。 </li><li>在模具上倒脱气PDMS混合物的一小部分，并让PDMS回流，实现了平坦的顶面（ 图3C）。 </li><li>将模具在烘箱中的PDMS在70℃下搅拌2小时以完全固化的PDMS。 </li><li>从取出模具烘箱和剥离PDMS关闭（ 图3D）。 </li></ol> 6，从供体基板检索墨水和打印目标区域上<ol><li>将供体基板上电动旋转和X，配备了显微镜y平移阶段。 </li><li>装上微尖戳一个独立的垂直平移阶段。 </li><li>在显微镜下，配合使用的平移和旋转阶段在施主衬底上的硅墨的微尖的邮票。此外，做了微尖的表面与Si墨水通过调整倾斜阶段之间的倾斜取向。随后，把微尖戳下来进行接触。 </li><li>初次接触后，慢慢把微尖戳进一步下降，从而使小技巧完全倒塌，整个表面是在与供体基底的硅墨水接触。 </li><li>迅速提高z载物台，打破了锚由于微尖戳和Si墨水之间的接触面积较大，对r从供体基板etrieve硅墨水，并将其附加到微尖戳。 注意:当微尖的邮票是没有任何压力，压缩的微尖恢复到原来的金字塔形状，使得与检索到的硅墨水最小的接触。 </li><li>放置在接收基板上一个x，y平移阶段和对齐检索的硅墨下在所需位置的微尖的邮票。 </li><li>下降的Z阶段，直到检索到硅墨勉强使得与接收器基板接触。 </li><li>使接触后，慢慢地提高该Z载台，以释放硅墨水，在所希望的位置打印。 </li></ol> 7，粘接工艺<ol><li>程序的快速热退火炉中循环从室温上升至950℃，在90秒，保持在950℃下进行10分钟，并冷却至室温（通过除去在炉中的任何供热）。 </li><li>将打印接收基板在炉中的环境空气环境和退火，在​​950℃C为10分钟为的Si-Si键合，或在360℃下30分钟，对硅 - 金键合。 </li></ol>

<ol>
	<li>Stix, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+&#8220;Point+one.">Toward &#8220;Point one.</a> Sci Am. Feb. , 90-95 (1995).</li><li>Appenzeler, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Man+Who+Dared+to+Think+Small.">The Man Who Dared to Think Small.</a> Science. 254, 1300-1301 (1991).</li><li>Madou, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fundamentals+of+Microfabrications+The+Science+of+Miniaturization.">Fundamentals of Microfabrications The Science of Miniaturization.</a> , (2002).</li><li>Xia, Y., 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> Angew Chem Int Ed. 38, 551-575 (1998).</li><li>Judy, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microelectromechanical+systems+(MEMS)+fabrication,+design+and+applications.">Microelectromechanical systems (MEMS) fabrication, design and applications.</a> Smart Mater Struct. 10, 1134-1154 (2001).</li><li>Jain, V. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Micromanufacturing Process. , (2012).</li><li>Keum, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silicon+micro-masonry+using+elastomeric+stamps+for+three-dimensional+microfabrication.">Silicon micro-masonry using elastomeric stamps for three-dimensional microfabrication.</a> J Micromech Microeng. 22, 55018 (2012).</li><li>Keum, H., Chung, H., Kim, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+Contact+at+The+Interface+between+Silicon+and+Transfer-Printed+Gold+Films+by+Eutectic+Joining.">Electrical Contact at The Interface between Silicon and Transfer-Printed Gold Films by Eutectic Joining.</a> ACS Appl Mater Interfaces. 5, 6061 (2013).</li><li>Keum, H., Seong, M., Sinha, S., Kim, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrostatically+Driven+Collapsible+Au+Thin+Films+Assembled+Using+Transfer+Printing+for+Thermal+Switching.">Electrostatically Driven Collapsible Au Thin Films Assembled Using Transfer Printing for Thermal Switching.</a> Appl Phys Lett. 100, 211904 (2012).</li><li>Klaassen, E. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silicon+fusion+bonding+and+deep+reactive+ion+etching:+a+new+technology+for+microstructures.">Silicon fusion bonding and deep reactive ion etching: a new technology for microstructures.</a> Sens Actuators A. 52, 132-139 (1996).</li><li>Barth, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silicon+fusion+bonding+for+fabrication+of+sensors+actuators+and+microstructures.">Silicon fusion bonding for fabrication of sensors actuators and microstructures.</a> Sens Actuators. A21 - A23, 919-926 (1990).</li></ol>

The authors have nothing to disclose.

微砖石，在图4中提出的，涉及硅熔融键合在一材料粘接工序。硅熔融键合是通过将样品中的快速热退火炉（RTA炉）和样品加热至950℃保持10分钟来实现。这种退火条件是双方可采用习之-硅和硅- 二氧化硅结合10,11。可替代地，结合有硅条如在图5C中发现的凹采用共晶键合，因此，该粘合温度是大约在Si-Au共晶体的温度（363℃）30分钟8。以确保共晶键...

微机电系统（MEMS），如大型普通三维机器的小型化，是必不可少的通过提供增强性能和降低制造成本的1,2推进现代技术。但是，不能维持在MEMS技术进步的现行税率不连续创新的制造技术3-6。常见的单片微加工主要依赖层 - 层过程的集成电路（IC）的制造开发。这种方法已经在使批量生产高性能的MEMS器件相当成功的。但是，由于其复杂的层 - 层和电化学性质减色，制造多样形状的3D MEMS结构和设备，同时便于在宏观世界，是非常具有挑战性的，以实现使用这种单片微加工。为了让更多的灵活的三维微细加工用量少过程的复杂性，我们德韦大步三维添加剂micromanufacturing策略（称为"微/纳米砖石&#39;），它涉及的微/纳米材料的转移印花为基础的组装与快速热退火功能材料粘接技术相结合。 转印是一种方法，从那里它们被使用的弹性体邮票控制干附着力产生或生长到不同衬底上的衬底转移固体微尺度材料（ 即，"固体墨"）。微砌体的典型过程开始转移印花。预制的固体油墨转印用微针戳即弹性邮票的一种高级形式，并在印刷结构被采用快速热退火（RTA），以提高油墨的油墨和油墨 - 基底粘附随后退火打印。该制造方法能够使异常微尺度结构和设备不能使用其他现有METHO收容的结构DS 7。 微砖石提供了不存在在其他方法中的一些吸引人的特点:（一）整合异种材料的功能和结构的固体油墨组装MEMS传感器的能力和执行器的三维结构中都集成; （二）组装的固体油墨的接口都可以充当电及热接触9,10; （三）装配空间分辨率可高（〜1微米）通过利用高度可扩展和易于理解的平版印刷工艺产生的固体油墨和高精密的 ​​机械阶段的转移印花7;及（d）的功能和结构的固体油墨可集成在刚性和柔性基板中的平面或曲线的几何形状。

<table><tbody><tr><td>Az 5214</td><td>Clariant</td><td></td><td>1.5 mm thick Photoresist</td></tr><tr><td>Su8-100</td><td>Microchem</td><td></td><td>100 mm Photoresist used in mold</td></tr><tr><td>Sylgard 184</td><td>Dow Corning</td><td></td><td>PDMS mixed to fabricate stamp</td></tr><tr><td>Hydrofluoric acid</td><td>Honeywell</td><td></td><td>Acid to etch silicon oxide layer</td></tr><tr><td>Silicon on insulator</td><td>Ultrasil</td><td></td><td>Donor substrate was fabricated</td></tr><tr><td>Trichlorosilane</td><td>Sigma-Aldrich</td><td></td><td>Chemical used to help pealing of PDMS from mold</td></tr></tbody></table>

micro-masonry for 3d additive micromanufacturing

转印是一种方法来从在那里它们被通过利用弹性体邮票产生一个不同的衬底上的衬底转移固体微/纳米级材料（在本文中被称为"油墨"）。转移印花使异质材料的集成制造被发现在最近的先进设备，如灵活和可拉伸的太阳能电池和LED阵列，无可比拟的结构或功能系统。而转移印花表现出料组件能力的独特功能，利用粘接剂层或表面改性，例如自组装单层（SAM）在基板上用于增强印刷工艺沉积阻碍了其广泛适应于微组装微机电系统（MEMS）结构和设备。为了克服这一缺点，我们开发了转移印花的先进模式，确定性仅仅通过控制表面的接触面积组装个人微尺度物体没有任何表面变化。由于没有粘接剂层或其它修饰和随后的材料键合过程中确保不仅机械结合，但组装材料之间还热和电的连接，从而进一步打开以适应不同的应用在构建寻常的MEMS器件。

微砌体使异质材料结合产生的MEMS结构，是非常具有挑战性的或不可能实现的单片微加工工艺。为了说明其功能，结构（称为"微茶壶&#39;）被制成仅通过微砌筑。 图4A是在一个施主衬底制造硅油墨的光学显微镜图像。所设计的墨是光盘与由单结晶硅的尺寸不同，它们是微茶壶的积木。一旦施主衬底被独立地准备，光盘是转移印刷到一个接收基板和层采用微尖戳， 如图4B退?...

Watch this Scientific Journal Video about Micro-masonry for 3D Additive Micromanufacturing at JoVE.com

Micro-masonry for 3D Additive Micromanufacturing

本文介绍了一种3D添加剂micromanufacturing策略（称为"微砌体&#39;）的微机电系统（MEMS）的结构和设备的柔性制造。这种方法涉及与快速热退火功能材料粘接技术相结合转移印花为主的微/纳米材料组装。

微砌筑的3D添加剂Micromanufacturing

Transfer printing is a method to transfer solid micro/nanoscale materials (herein called &#8216;inks&#8217;) from a substrate where they are generated to ...

micro-masonry-for-3d-additive-micromanufacturing

Research

Education

JoVE Core

JoVE Journal

Civil Engineering

Engineering

Unit 1

Masonry

SCIENTISTS IN ACTION

10.3K 次观看.  University of Illinois at Urbana-Champaign. 本文介绍了一种3D添加剂micromanufacturing策略（称为"微砌体'）的微机电系统（MEMS）的结构和设备的柔性制造。这种方法涉及与快速热退火功能材料粘接技术相结合转移印花为主的微/纳米材料组装。 

视频: Micro-masonry for 3D Additive Micromanufacturing

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 ...

科研

化学

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 ...

生物学

A Soft Tooling Process Chain for Injection Molding of a 3D Component with Micro Pillars

The purpose of this paper is to present the method of a soft tooling process chain employing Additive Manufacturing (AM) for fabrication of injection molding inserts with micro surface features. The Soft Tooling inserts are manufactured by Digital Light Processing (vat photo polymerization) using a photopolymer that can withstand relatively high temperaturea. The part manufactured here has four tines with an angle of 60&#176;. Micro pillars (&#216;200 &#181;m, aspect ratio of 1) are arranged on the surfaces by two rows. Polyethylene (PE) injection molding with the soft tooling inserts is used to fabricate the final parts. This method demonstrates that it is feasible to obtain injection-molded parts with microstructures on complex geometry by additive manufactured inserts. The machining time and cost is reduced significantly compared to conventional tooling processes based on computer numerical control (CNC) machining. The dimensions of the micro features are influenced by the applied additive manufacturing process. The lifetime of the inserts determines that this process is more suitable for pilot production. The precision of the inserts production is limited by the additive manufacturing process as well.

A protocol for fabricating injection molding inserts for complex geometry with micro features on surfaces employing Additive Manufacturing (AM) is presented.

微柱3D 构件注塑成型的软加工工艺链

The purpose of this paper is to present the method of a soft tooling process chain employing Additive Manufacturing (AM) for fabrication of injection ...

工程学

Multi-material Ceramic-Based Components &#8211; Additive Manufacturing of Black-and-white Zirconia Components by Thermoplastic 3D-Printing (CerAM - T3DP)

To combine the benefits of Additive Manufacturing (AM) with the benefits of Functionally Graded Materials (FGM) to ceramic-based 4D components (three dimensions for the geometry and one degree of freedom concerning the material properties at each position) the Thermoplastic 3D-Printing (CerAM -&#160;T3DP) was developed. It is a direct AM technology which allows the AM of multi-material components. To demonstrate the advantages of this technology black-and-white zirconia components were additively manufactured and co-sintered defect-free.
Two different pairs of black and white zirconia powders were used to prepare different thermoplastic suspensions. Appropriate dispensing parameters were investigated to manufacture single-material test components and adjusted for the additive manufacturing of multi-color zirconia components.

Here we describe a protocol for additively manufacturing black-and-white zirconia components by Thermoplastic 3D-Printing (CerAM -&#160;T3DP) and co-sintering defect-free.

多材料陶瓷基元器件--用热塑性3d 印刷 (ceram-t3dp) 制备黑白氧化锆部件的添加剂

To combine the benefits of Additive Manufacturing (AM) with the benefits of Functionally Graded Materials (FGM) to ceramic-based 4D components (three ...

Additive Manufacturing of Functionally Graded Ceramic Materials by Stereolithography

An additive manufacturing technology is applied to obtain functionally graded ceramic parts. This technology, based on digital light processing/stereolithography, is developed within the scope of the CerAMfacturing European research project. A three-dimensional (3-D) hemi-maxillary bone-like structure is 3-D printed using custom aluminum oxide polymeric mixtures. The powders and mixtures are fully analyzed in terms of rheological behavior in order to ensure proper material handling during the printing process. The possibility to print functionally graded materials using the Admaflex technology is explained in this document. Field-emission scanning electron microscopy (FESEM) show that the sintered aluminum oxide ceramic part has a porosity lower than 1% and no remainder of the original layered structure is found after analysis.

This manuscript describes the processing of single multifunctional ceramic components (e.g., combinations of dense-porous structures) additively manufactured by stereolithography.

立体平版印刷法对功能分级陶瓷材料的添加剂制造

An additive manufacturing technology is applied to obtain functionally graded ceramic parts. This technology, based on digital light ...

Negative Additive Manufacturing of Complex Shaped Boron Carbides

Boron carbide (B4C) is one of the hardest materials in existence. However, this attractive property also limits its machineability into complex shapes for high wear, high hardness, and lightweight material applications such as armors. To overcome this challenge, negative additive manufacturing (AM) is employed to produce complex geometries of boron carbides at various length scales. Negative AM first involves gelcasting a suspension into a 3D-printed plastic mold. The mold is then dissolved away, leaving behind a green body as a negative copy. Resorcinol-formaldehyde (RF) is used as a novel gelling agent because unlike traditional hydrogels, there is little to no shrinkage, which allows for extremely complex molds to be used. Furthermore, this gelling agent can be pyrolyzed to leave behind ~50 wt% carbon, which is a highly effective sintering aid for B4C. Due to this highly homogenous distribution of in situ carbon within the B4C matrix, less than 2% porosity can be achieved after sintering. This protocol highlights in detail the methodology for creating near fully dense boron carbide parts with highly complex geometries.

A method called negative additive manufacturing is used to produce near fully dense complex shaped boron carbide parts of various length scales. This technique is possible via the formulation of a novel suspension involving resorcinol-formaldehyde as a unique gelling agent that leaves behind a homogenous carbon sintering aid after pyrolysis.

复合型碳化硼的负添加剂制造

Boron carbide (B4C) is one of the hardest materials in existence. However, this attractive property also limits its machineability into complex shapes for ...

Micropatterning and Assembly of 3D Microvessels

In vitro platforms to study endothelial cells and vascular biology are largely limited to 2D endothelial cell culture, flow chambers with polymer or glass based substrates, and hydrogel-based tube formation assays. These assays, while informative, do not recapitulate lumen geometry, proper extracellular matrix, and multi-cellular proximity, which play key roles in modulating vascular function. This manuscript describes an injection molding method to generate engineered vessels with diameters on the order of 100 &#181;m. Microvessels are fabricated by seeding endothelial cells in a microfluidic channel embedded within a native type I collagen hydrogel. By incorporating parenchymal cells within the collagen matrix prior to channel formation, specific tissue microenvironments can be modeled and studied. Additional modulations of hydrodynamic properties and media composition allow for control of complex vascular function within the desired microenvironment. This platform allows for the study of perivascular cell recruitment, blood-endothelium interactions, flow response, and tissue-microvascular interactions. Engineered microvessels offer the ability to isolate the influence from individual components of a vascular niche and precisely control its chemical, mechanical, and biological properties to study vascular biology in both health and disease.

This manuscript presents an injection molding method to engineer microvessels that recapitulate physiological properties of endothelium. The microfluidic-based process creates patent 3D vascular networks with tailorable conditions, such as flow, cellular composition, geometry, and biochemical gradients. The fabrication process and examples of potential applications are described.

缩微和3D微血管大会

In vitro platforms to study endothelial cells and vascular biology are largely limited to 2D endothelial cell culture, flow chambers with polymer or glass ...

生物工程

Design and Development of a Three-Dimensionally Printed Microscope Mask Alignment Adapter for the Fabrication of Multilayer Microfluidic Devices

This project aims to develop an easy-to-use and cost-effective platform for the fabrication of precise, multilayer microfluidic devices, which typically can only be achieved using costly equipment in a clean room setting. The key part of the platform is a three dimensionally (3D) printed microscope mask alignment adapter (MMAA) compatible with regular optical microscopes and ultraviolet (UV) light exposure systems. The overall process of creating the device has been vastly simplified because of the work done to optimize the device design. The process entails finding the proper dimensions for the equipment available in the laboratory and 3D-printing the MMAA with the optimized specifications. Experimental results show that the optimized MMAA designed and manufactured by 3D printing performs well with a common microscope and light exposure system. Using a master mold prepared by the 3D-printed MMAA, the resulting microfluidic devices with multilayered structures contain alignment errors of &lt;10 &#181;m, which is sufficient for common microchips. Although human error through transportation of the device to the UV light exposure system can cause larger fabrication errors, the minimal errors achieved in this study are attainable with practice and care. Furthermore, the MMAA can be customized to fit any microscope and UV exposure system by making changes to the modeling file in the 3D printing system. This project provides smaller laboratories with a useful research tool as it only requires the use of equipment that is typically already available to laboratories that produce and use microfluidic devices. The following detailed protocol outlines the design and 3D printing process for the MMAA. In addition, the steps for procuring a multilayer master mold using the MMAA and producing poly(dimethylsiloxane) (PDMS) microfluidic chips is also described herein.

This project allows small laboratories to develop an easy-to-use platform for the fabrication of precise multilayer microfluidic devices. The platform consists of a three-dimensionally printed microscope mask alignment adapter using which multilayer microfluidic devices with alignment errors of &lt;10 &#181;m were achieved.

设计和开发用于制造多层微流体设备的三维打印显微镜面膜对齐适配器

This project aims to develop an easy-to-use and cost-effective platform for the fabrication of precise, multilayer microfluidic devices, which typically ...

Computer Numerical Control Micromilling of a Microfluidic Acrylic Device with a Staggered Restriction for Magnetic Nanoparticle-Based Immunoassays

Microfluidic systems have greatly improved immunoassay techniques. However, many microfabrication techniques require specialized, expensive, or complicated equipment, making fabrication costly and incompatible with mass production, which is one of the most important preconditions for point-of-care tests (POCT) to be adopted in low-resource settings. This work describes the fabrication process of an acrylic (polymethylmethacrylate, PMMA) device for nanoparticle-conjugated enzymatic immunoassay testing using the computer numerical control (CNC) micromilling technique. The functioning of the microfluidic device is shown by performing an immunoassay to detect a commercial antibody using lysozyme as a model antigen conjugated to 100 nm magnetic nanoparticles. This device integrates a physical staggered restriction of only 5 &#181;m in height, used to capture magnetic microparticles that make up a magnetic trap by placing an external magnet. In this way, the magnetic force on the immunosupport of conjugated nanoparticles is enough to capture them and resist flow drag. This microfluidic device is particularly suitable for low-cost mass production without the loss of precision for immunoassay performance.

Microfluidics is a powerful tool for the development of diagnostic tests. However, expensive equipment and materials, as well as laborious fabrication and handling techniques, are often required. Here, we detail the fabrication protocol of an acrylic microfluidic device for magnetic micro- and nanoparticle-based immunoassays in a low-cost and simple-to-use setting.

基于磁性纳米颗粒免疫分析的交错限制微流控亚克力装置的计算机数控微铣削

Microfluidic systems have greatly improved immunoassay techniques. However, many microfabrication techniques require specialized, expensive, or ...

An Additive Manufacturing Technique for the Facile and Rapid Fabrication of Hydrogel-based Micromachines with Magnetically Responsive Components

Polyethylene glycol (PEG)-based hydrogels are biocompatible hydrogels that have been approved for use in humans by the FDA. Typical PEG-based hydrogels have simple monolithic architectures and often function as scaffolding materials for tissue engineering applications. More sophisticated structures typically take a long time to fabricate and do not contain moving components. This protocol describes a photolithography method that allows for facile and rapid microfabrication of PEG structures and devices. This strategy involves an in-house developed fabrication stage that allows for the rapid fabrication of 3D structures by building upwards in a layer-by-layer fashion. Independent moving components can also be aligned and assembled onto support structures to form integrated devices. These independent components are doped with superparamagnetic iron oxide nanoparticles that are sensitive to magnetic actuation. In this manner, the fabricated devices can be actuated using external magnets to yield movement of the components within. Hence, this technique allows for the fabrication of sophisticated MEMS-like devices (micromachines) that are composed entirely out of a biocompatible hydrogel, able to function without an onboard power source, and respond to a contact-less method of actuation. This manuscript describes the fabrication of both the fabrication set-up as well as the step-by-step method for the microfabrication of these hydrogels-based MEMS-like devices.

An additive manufacturing strategy for processing UV-crosslinkable hydrogels has been developed. This strategy allows for the layer-by-layer assembly of microfabricated hydrogel structures as well as the assembly of independent components, yielding integrated devices containing moving components that are responsive to magnetic actuation.

一种简便快速制备磁响应元件的水凝胶基微型机械的添加剂制造技术

Polyethylene glycol (PEG)-based hydrogels are biocompatible hydrogels that have been approved for use in humans by the FDA. Typical PEG-based hydrogels ...