AFOSR青年研究者计划下FA9550-12-1-0352和3M非终身制教师奖，这项工作是支持。笔者想，感谢Lalisa Stutts和Janine汤姆有益的讨论，有关这个项目的。作者感谢的Calit2显微镜中心和激光光谱学设施，尔湾加州大学允许使用其设施。霍奇哈兰德与UCI物理科学车间公认的制作工具。聚（乳酸）乳酸纤维帝人单丝慷慨提供。

1。催化牺牲纤维<ol><li>包装所需量的聚（乳酸）乳酸纤维围绕降低¾定制的主轴。减少纤维的重叠，以提供最大的表面积暴露。 </li><li>剂Disperbyk 130在一个封闭的瓶用40ml去离子H 2 O混合并摇动，直到获得均匀的溶液。然后将1000毫升烧杯中，在37℃水浴中，并放入烧杯中倒入三氟。 H 2 O和TFE使用量取决于，PLA纤维直径。 <table border="1"><tbody><tr><td> 光纤直径 </td><td> 量的H 2 O（毫升） </td><td> 金额TFE（毫升） </td></tr><tr><td> 200 </td><td> 400 </td><td> 400 </td></tr><tr><td> 300 </td><td> 360 </td><td> 440 </td></tr><tr><td> 500 </td><td> 320 </td><td> 480 </td></tr></tbody></table></li><li>加H 2 O / DISPERBYK 187溶液的烧杯中，并搅拌直至均匀。 </li><li>添加1克孔雀石绿的混合物，搅拌至溶解。 </li><li>纤维烧杯中的半英寸从底部将安装主轴和主轴连接到数字混频器。然后启动数字调音台每分钟400转。 </li><li>向混合物中慢慢加入1.3克锡（II），草酸（SNOX）的催化剂。 SNOX除了必须循序渐进，以防止材料的大型群崩溃的解决方案。 </li><li>在混合物中的pH调节用NaOH直至pH是6.8-7.2〜。 </li><li>的盖固定到烧杯中，并增加了24小时，以每分钟500转的主轴旋转。观察SNOX如果结块，手动前2小时内打破它。 </li><li>拆下主轴，并在烘箱中干燥，在35℃下保温过夜。 </li><li>拆开并去除多余的催化剂催化聚乳酸纤维。 </li></ol> 2。微血管燃气EXCHANGE单位制造<ol><li>获取一个对激光切割黄铜图案铜板的剪辑持有人所需的微血管图案，并加盖板。 </li><li>切割10英寸长的催化膳食纤维微通道，并删除任何剩余的催化剂使用较厚的板切纤维直径（平局板）。 </li><li>锥形的边缘纤维用热胶枪的尖端慢慢挤出纤维的提示。 </li><li>螺纹黄铜图案板对纤维通过对应的孔中。 </li><li>用螺丝将板成型盒上。确保纤维在安装板时，没有扭曲。 </li><li>弦乐纤维提示通过调谐钉定制张紧板。 </li><li>直到绷紧的张力聚乳酸纤维。要小心，不要过度紧张和捕捉纤维。 </li><li>删除多余的颗粒用压缩空气从光纤模式。 </li><li>混合聚二甲基硅氧烷（PDMS）基与固化剂以10:1，V：V比。 </lI&gt; <li>混合物在真空下脱气10分钟，在干燥器中jar文件。 </li><li>倒入的PDMS混合物送入模箱。不要直接倒在纤维，以减少气泡俘获。 </li><li>使用26 G针，取出成型箱或纤维之间的任何气泡内。 </li><li>固化的PDMS混合物在85℃下30分钟。 </li><li>松开铜板模箱，确保不要弯曲板或用力太猛。从模具中取出固化第一阶段。 </li><li>线程的纤维通过RTV端盖，在端盖用注射器穿刺孔。根据纤维的大小，使用的针测量仪，该测量仪具有至少2倍的内直径的外直径的纤维。作为黄铜图案板保持了类似的模式，但更广泛地传播出去。 </li><li>端盖固定到一个更大的模框的两端，倒第二阶段的PDMS。 </li><li>删除任何剩余的气泡和在85℃下固化30分钟。 </li><li>切从样品在真空烘箱中在210℃下放置24小时，或直至该聚乳酸纤维大多已抽真空的任何多余的聚乳酸纤维。 </li><li>不能被删除，如果没有PLA，温和地溶解出的使用注射1毫升氯仿中的微通道。 </li></ol>

<ol>
	<li>Bellan, L. M., Singh, S. P., Henderson, P. W., Porri, T. J., Craighead, H. G., Spector, J. A. <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+an+artificial+3-dimensional+vascular+network+using+sacrificial+sugar+structures.">Fabrication of an artificial 3-dimensional vascular network using sacrificial sugar structures.</a> Soft Matter. 5 (7), 1354 (2009).</li><li>Bellan, L. M., Strychalski, E. A., Craighead, H. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nano-channels+fabricated+in+polydimethylsiloxane+using+sacrificial+electrospun+polyethylene+oxide+nanofibers.">Nano-channels fabricated in polydimethylsiloxane using sacrificial electrospun polyethylene oxide nanofibers.</a> J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. Process. Meas. Phenom. 26 (5), 1728 (2008).</li><li>Borenstein, J. T., Weinberg, E. J., Orrick, B. K., Sundback, C., Kaazempur-Mofrad, M. R., Vacanti, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfabrication+of+three-dimensional+engineered+Scaffolds.">Microfabrication of three-dimensional engineered Scaffolds.</a> Tissue Eng. 13 (8), 1837-1844 (2007).</li><li>Wu, H., Odom, T. W., Chiu, D. T., 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=Fabrication+of+complex+three-dimensional+microchannel+systems+in+PDMS.">Fabrication of complex three-dimensional microchannel systems in PDMS.</a> J. Am. Chem. Soc. 125 (2), 554-559 (2003).</li><li>Trask, R. S., Bond, I. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomimetic+self-healing+of+advanced+composite+structures+using+hollow+glass+fibres.">Biomimetic self-healing of advanced composite structures using hollow glass fibres.</a> Smart Mater. Struct. 15 (3), 704-710 (2006).</li><li>Dong, H., Esser-Kahn, A. P., 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=Chemical+treatment+of+poly(lactic+acid)+fibers+to+enhance+the+rate+of+thermal+depolymerization.">Chemical treatment of poly(lactic acid) fibers to enhance the rate of thermal depolymerization.</a> ACS Appl. Mater. Interfaces. 4 (2), 503-509 (2012).</li><li>Esser-Kahn, A. P., Thakre, P. R., 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=Three-dimensional+microvascular+fiber-reinforced+composites.">Three-dimensional microvascular fiber-reinforced composites.</a> Adv. Mater. 23 (32), 3654-3658 (2011).</li><li>White, S. R., Blaiszik, B. J., Kramer, S. L. B., Olugebefola, S. C., Moore, J. S., Sottos, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-healing+polymers+and+composites.">Self-healing polymers and composites.</a> Am. Sci. 99 (5), 392 (2011).</li><li>Nguyen, D. T., Leho, Y. T., Esser-Kahn, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+three-dimensional+microvascular+gas+exchange+unit+for+carbon+dioxide+capture.">A three-dimensional microvascular gas exchange unit for carbon dioxide capture.</a> Lab Chip. 12 (7), 1246 (2012).</li><li>Nguyen, D. T., Leho, Y. T., Esser-Kahn, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+membrane+thickness+on+a+microvascular+gas+exchange+unit.">The effect of membrane thickness on a microvascular gas exchange unit.</a> Adv. Funct. Mater. , (2012).</li></ol>

我们已经申请了临时专利这项技术和美国专利美国临时申请序列号61/590，086。

的SNOX催化剂的成聚乳酸纤维的引入允许在较低温度下的纤维的解聚。这可以防止嵌入树脂的降解，在这种情况下的PDMS。一个自定义的主轴需要正确地混合处理液（ 图5A）。主轴由六个支撑棒附加到数字混频器的中心纤芯周围。将纤维缠与催化剂溶液接触的包装的纤维的表面积最大化，使支承杆。包含主轴的底部一组叶片引入混沌流动。的乱流，防止附聚的催化剂。 <p class="jove_cont...

自然系统使用广泛的血管网络，方便许多生物功能。大众运输可以有效地实现，在这种系统中，由于高的表面积与体积比和优化包装结构。虽然许多合成制造技术可以产生微血管结构，没有人能生产大型微血管的复杂性和兼容性，同时保持与现有的制造方法1-5。如禽流肺的结构提供了灵感。我们如何制造这种复杂的结构，提高大众交通工具吗？ 汽化牺牲组件（VASC）的生产规模大，复杂的微血管结构6-7。此方法使用的热解聚和聚（乳酸）乳酸纤维，形成中空纤维模板的逆通道的蒸发除去。这是一个牺牲的技术与现有的制造的方法。米长，可以使用此制造过程中形成的圆筒状微通道型态。这可以被用来创建血管化设备，如自愈7至10的聚合物和三维微血管碳捕获单元。 碳捕获单元灵感禽流肺，提供了一个有效的气体交换 - 重量比，由于在飞行途中使用。 parabronchus组成的六边形图案的微通道，它提供了高瓦斯汇率和结构稳定的气体交换单位。为了创建交换单元微型三维对齐功能，我们开发了使用自定义吉他调谐器和激光微加工板设计张力板独立拉紧纤维的方法。每根纤维由外部的张力保持在适当位置，由放置在板中的孔，通过该纤维的运行模式被设置。

<table border="1">
	<tbody>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Reagent</td>
		</tr>
		<tr>
			<td>Tin (II) oxalate</td>
			<td>Sigma-Aldrich</td>
			<td>402761</td>
			<td></td>
		</tr>
		<tr>
			<td>Disperbyk 130</td>
			<td>BYK Additives &#38; Instruments</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Trifluoroethanol</td>
			<td>Halocarbon</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Malachite Green (technical grade)</td>
			<td>Sigma-Aldrich</td>
			<td>M6880</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide (&#8805;98%, pellets)</td>
			<td>Sigma-Aldrich</td>
			<td>S5881</td>
			<td></td>
		</tr>
		<tr>
			<td>Polydimethylsiloxane (PDMS)</td>
			<td>Dow Corning</td>
			<td>3097358-1004</td>
			<td>Distributed from Ellsworth Adhesives</td>
		</tr>
		<tr>
			<td>Poly(lactic) acid fibers</td>
			<td>Teijin Monofilament</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Material</td>
		</tr>
		<tr>
			<td>RW 20 Digital Mixer</td>
			<td>IKA</td>
			<td>3593001</td>
			<td></td>
		</tr>
		<tr>
			<td>Desiccator Jar</td>
			<td>Pyrex</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum Oven</td>
			<td>Fisher Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Third Hand</td>
			<td>Jameco Electronics</td>
			<td>26690</td>
			<td>Plate holder</td>
		</tr>
		<tr>
			<td>Glue Gun</td>
			<td>Stanley</td>
			<td>GR20L</td>
			<td></td>
		</tr>
		<tr>
			<td>PLA Spindle</td>
			<td></td>
			<td></td>
			<td>Custom made</td>
		</tr>
		<tr>
			<td>Tensioning Board</td>
			<td></td>
			<td></td>
			<td>Custom made</td>
		</tr>
	</tbody>
</table>

process of making three-dimensional microstructures using vaporization of a sacrificial component

在自然系统中的血管结构通过高比表面积和优化结构，能够提供高质量传输。几个合成材料制造技术保持可扩展性的同时，能够模拟这些结构的复杂性。汽化一个祭祀元器件（VASC）的过程是能够做到这一点。此过程中使用牺牲纤维作为模板，以形成空心的圆筒形的嵌入在一个矩阵中的微通道。锡（II），草酸（SNOX）的嵌入于聚（乳酸）乳酸（PLA）纤维，在此过程中有利于使用。的的SNOX催化解聚的聚乳酸纤维在较低温度下。乳酸的单体气体在这些温度下，可以在不损伤基体的温度从嵌入的矩阵除去。在这里，我们使用微机械板和张紧装置来创建复杂的三维排列的微通道模式使这些纤维的方法。该过程允许任意排列的纤维的探索拓扑和结构。

本程序提供了嵌入树脂中的微血管结构的制造方法。这些结构可以符合各种图案（ 图2）。仅受限于微血管网络的结构，可以形成与牺牲纤维结构。 使用平行排列的微血管通道，流体流的气体之间的运输容易气体遍历信道间的可渗透膜。这些设备可以在一个可扩展的方式制造的光刻而不需要（ 图3）。所形成的微通道是完全空心的，可以相隔小于50μm?...

Watch this Scientific Journal Video about Process of Making Three-dimensional Microstructures using Vaporization of a Sacrificial Component at JoVE.com

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

的汽化一个祭祀元器件（VASC）的过程中，用于制造微血管结构。此过程使用牺牲聚乳酸纤维（乳酸），形成空心微所提供的激光微加工导光板的精确的三维几何定位。

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 ...

process-making-three-dimensional-microstructures-using-vaporization

Research

JoVE Journal

Engineering

9.0K 次观看.  University of California, Irvine. 的汽化一个祭祀元器件（VASC）的过程中，用于制造微血管结构。此过程使用牺牲聚乳酸纤维（乳酸），形成空心微所提供的激光微加工导光板的精确的三维几何定位。 

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

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

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip devices, and their applications. In particular, capabilities for cost-effective fabrication of polymer microstructures were transformed by the advent of soft lithography and other micromolding techniques 1, 2, and this led a revolution in applications of microfabrication to biomedical engineering and biology. Nevertheless, it remains challenging to fabricate microstructures with well-defined nanoscale surface textures, and to fabricate arbitrary 3D shapes at the micro-scale. Robustness of master molds and maintenance of shape integrity is especially important to achieve high fidelity replication of complex structures and preserving their nanoscale surface texture. The combination of hierarchical textures, and heterogeneous shapes, is a profound challenge to existing microfabrication methods that largely rely upon top-down etching using fixed mask templates. On the other hand, the bottom-up synthesis of nanostructures such as nanotubes and nanowires can offer new capabilities to microfabrication, in particular by taking advantage of the collective self-organization of nanostructures, and local control of their growth behavior with respect to microfabricated patterns. 
Our goal is to introduce vertically aligned carbon nanotubes (CNTs), which we refer to as CNT "forests", as a new microfabrication material. We present details of a suite of related methods recently developed by our group: fabrication of CNT forest microstructures by thermal CVD from lithographically patterned catalyst thin films; self-directed elastocapillary densification of CNT microstructures; and replica molding of polymer microstructures using CNT composite master molds. In particular, our work shows that self-directed capillary densification ("capillary forming"), which is performed by condensation of a solvent onto the substrate with CNT microstructures, significantly increases the packing density of CNTs. This process enables directed transformation of vertical CNT microstructures into straight, inclined, and twisted shapes, which have robust mechanical properties exceeding those of typical microfabrication polymers. This in turn enables formation of nanocomposite CNT master molds by capillary-driven infiltration of polymers. The replica structures exhibit the anisotropic nanoscale texture of the aligned CNTs, and can have walls with sub-micron thickness and aspect ratios exceeding 50:1. Integration of CNT microstructures in fabrication offers further opportunity to exploit the electrical and thermal properties of CNTs, and diverse capabilities for chemical and biochemical functionalization 3.

We present methods for fabrication of patterned microstructures of vertically aligned carbon nanotubes (CNTs), and their use as master molds for production of polymer microstructures with organized nanoscale surface texture. The CNT forests are densified by condensation of solvent onto the substrate, which significantly increases their packing density and enables self-directed formation of 3D shapes.

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 ...

科研

工程学

Synthesis of Phase-shift Nanoemulsions with Narrow Size Distributions for Acoustic Droplet Vaporization and Bubble-enhanced Ultrasound-mediated Ablation

High-intensity focused ultrasound (HIFU) is used clinically to thermally ablate tumors. To enhance localized heating and improve thermal ablation in tumors, lipid-coated perfluorocarbon droplets have been developed which can be vaporized by HIFU. The vasculature in many tumors is abnormally leaky due to their rapid growth, and nanoparticles are able to penetrate the fenestrations and passively accumulate within tumors. Thus, controlling the size of the droplets can result in better accumulation within tumors. In this report, the preparation of stable droplets in a phase-shift nanoemulsion (PSNE) with a narrow size distribution is described. PSNE were synthesized by sonicating a lipid solution in the presence of liquid perfluorocarbon. A narrow size distribution was obtained by extruding the PSNE multiple times using filters with pore sizes of 100 or 200 nm. The size distribution was measured over a 7-day period using dynamic light scattering. Polyacrylamide hydrogels containing PSNE were prepared for in vitro experiments. PSNE droplets in the hydrogels were vaporized with ultrasound and the resulting bubbles enhanced localized heating. Vaporized PSNE enables more rapid heating and also reduces the ultrasound intensity needed for thermal ablation. Thus, PSNE is expected to enhance thermal ablation in tumors, potentially improving therapeutic outcomes of HIFU-mediated thermal ablation treatments.

Phase-shift nanoemulsions (PSNE) can be vaporized using high intensity focused ultrasound to enhance localized heating and improve thermal ablation in tumors. In this report, the preparation of stable PSNE with a narrow size distribution is described. Furthermore, the impact of vaporized PSNE on ultrasound-mediated ablation is demonstrated in tissue-mimicking phantoms.

相移窄粒度分布的纳米乳液的合成声波液滴蒸发和泡增强的超声介导消融

High-intensity  focused ultrasound (HIFU) is used clinically to thermally ablate tumors. To  enhance localized heating and improve thermal ablation in ...

High-resolution, High-speed, Three-dimensional Video Imaging with Digital Fringe Projection Techniques

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses triangulation between matching points in two views of the same scene at different angles to compute depth.&#160;However, unlike a stereo-based method, DFP uses a digital video projector to replace one of the cameras1. The projector rapidly projects a known sinusoidal pattern onto the subject, and the surface of the subject distorts these patterns in the camera&#8217;s field of view. Three distorted patterns (fringe images) from the camera can be used to compute the depth using triangulation.
Unlike other 3D measurement methods, DFP techniques lead to systems that tend to be faster, lower in equipment cost, more flexible, and easier to develop.&#160;DFP systems can also achieve the same measurement resolution as the camera.&#160;For this reason, DFP and other digital structured light techniques have recently been the focus of intense research (as summarized in1-5). Taking advantage of DFP, the graphics processing unit, and optimized algorithms, we have developed a system capable of 30&#160;Hz 3D video data acquisition, reconstruction, and display for over 300,000 measurement points per frame6,7.&#160;Binary defocusing DFP methods can achieve even greater speeds8.
Diverse applications can benefit from DFP techniques. Our collaborators have used our systems for facial function analysis9, facial animation10, cardiac mechanics studies11, and fluid surface measurements, but many other potential applications exist.&#160;This video will teach the fundamentals of DFP techniques and illustrate the design and operation of a binary defocusing DFP system.

This video describes the fundamentals of digital fringe projection techniques, which provide dense 3D measurements of dynamically changing surfaces.&#160;It also demonstrates the design and operation of a high-speed binary defocusing system based on these techniques.

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses ...

Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their behavior for single stages of a process or even an entire process. For the simulation with occurring particle-particle and particle-wall contacts, the value of the coefficient of restitution is required. It can be determined experimentally. The coefficient of restitution depends on several parameters like the impact velocity. Especially for fine particles the impact velocity depends on the air pressure and under atmospheric pressure high impact velocities cannot be reached. For this, a new experimental setup for free-fall tests under vacuum conditions is developed. The coefficient of restitution is determined with the impact and rebound velocity which are detected by a high-speed camera. To not hinder the view, the vacuum chamber is made of glass. Also a new release mechanism to drop one single particle under vacuum conditions is constructed. Due to that, all properties of the particle can be characterized beforehand.

The coefficient of restitution is a parameter that describes the loss of kinetic energy during collision. Here, a free-fall setup under vacuum conditions is developed to be able to determine the coefficient of restitution parameter for particles in micrometer range with high impact velocities.

实验装置的研制归还系数在真空条件下测量

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

有机硅为基础的介电弹性体致动器的制作工艺

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data acquisition times with high spatial resolution. In the electronics industry there is serious interest in performing failure analysis on 3D microelectronic packages, many which contain multiple levels of high-density interconnections. Often in tomography there is a trade-off between image resolution and the volume of a sample that can be imaged. This inverse relationship limits the usefulness of conventional computed tomography (CT) systems since a microelectronic package is often large in cross sectional area 100-3,600 mm2, but has important features on the micron scale. The micro-tomography beamline at the Advanced Light Source (ALS), in Berkeley, CA USA, has a setup which is adaptable and can be tailored to a sample&#39;s properties, i.e., density, thickness, etc., with a maximum allowable cross-section of 36 x 36 mm. This setup also has the option of being either monochromatic in the energy range ~7-43 keV or operating with maximum flux in white light mode using a polychromatic beam. Presented here are details of the experimental steps taken to image an entire 16 x 16 mm system within a package, in order to obtain 3D images of the system with a spatial resolution of 8.7 &#181;m all within a scan time of less than 3 min. Also shown are results from packages scanned in different orientations and a sectioned package for higher resolution imaging. In contrast a conventional CT system would take hours to record data with potentially poorer resolution. Indeed, the ratio of field-of-view to throughput time is much higher when using the synchrotron radiation tomography setup. The description below of the experimental setup can be implemented and adapted for use with many other multi-materials.

For this study synchrotron radiation micro-tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron&#39;s high flux and brightness the sample was imaged in just 3 min&#160;with an 8.7 &#181;m spatial resolution.

利用同步辐射微断层调查的多尺度三维微电子封装

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data ...

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic recording of image sequences. The basic components, features, constraints and optimization tips of a 3D-PTV topology consisting of a high-speed camera with a four-view splitter are described and discussed in this article. The technique is applied to the intermediate flow field (5 &#60;x/d &#60;25) of a circular jet at Re &#8776; 7,000. Lagrangian flow features and turbulence quantities in an Eulerian frame are estimated around ten diameters downstream of the jet origin and at various radial distances from the jet core. Lagrangian properties include trajectory, velocity and acceleration of selected particles as well as curvature of the flow path, which are obtained from the Frenet-Serret equation. Estimation of the 3D velocity and turbulence fields around the jet core axis at a cross-plane located at ten diameters downstream of the jet is compared with literature, and the power spectrum of the large-scale streamwise velocity motions is obtained at various radial distances from the jet core.

A three-dimensional particle tracking velocimetry (3D-PTV) system based on a high-speed camera with a four-view splitter is described here. The technique is applied to a jet flow from a circular pipe in the vicinity of ten diameters downstream at Reynolds number Re &#8776; 7,000.

湍流应用三维粒子跟踪测速：一喷流病例

3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

Challenges in Rheological Characterization of Highly Concentrated Suspensions &amp;#8212; A Case Study for Screen-printing Silver Pastes

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

挑战流变特性高度集中悬架 - 为例进行丝网印刷银浆

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a fixed bed are important phenomena in catalyst technology. The mechanical strength of the catalyst is measured here by its bending strength or flexural strength. This technique is relatively new from the perspective of applying it to commercial catalysts of typical sizes used in the industry. Catalyst breakage by collision against a surface is measured after a fall of the extrudates through the ambient air in a vertical pipe. Quantifying the impact force is done theoretically by applying Newton's second law. Measurement of catalyst breakage due to stress in a fixed bed is done following the standard procedure of the bulk crush strength test. Novel here is the focus on measuring the reduction in the length to diameter ratio of the extrudates as a function of the stress.

Here we present a protocol to measure the modulus of rupture of an extruded catalyst and the breakage of said catalyst extrudates by collision against a surface or by compression in a fixed bed.

基于断裂模量的催化剂挤出断裂预测

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a ...

Three-Dimensional Ultrasonic Needle Tip Tracking with a Fiber-Optic Ultrasound Receiver

Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. When visualization is lost, the medical device can cause trauma to critical tissue structures. Here, a method to track the needle tip during ultrasound image-guided procedures is presented. This method involves the use of a fiber-optic ultrasound receiver that is affixed within the cannula of a medical needle to communicate ultrasonically with the external ultrasound probe. This custom probe comprises a central transducer element array and side element arrays. In addition to conventional two-dimensional (2D) B-mode ultrasound imaging provided by the central array, three-dimensional (3D) needle tip tracking is provided by the side arrays. For B-mode ultrasound imaging, a standard transmit-receive sequence with electronic beamforming is performed. For ultrasonic tracking, Golay-coded ultrasound transmissions from the 4 side arrays are received by the hydrophone sensor, and subsequently the received signals are decoded to identify the needle tip&#39;s spatial location with respect to the ultrasound imaging probe. As a preliminary validation of this method, insertions of the needle/hydrophone pair were performed in clinically realistic contexts. This novel ultrasound imaging/tracking method is compatible with current clinical workflow, and it provides reliable device tracking during in-plane and out-of-plane needle insertions.

Accurate and efficient visualization of invasive medical devices is extremely important in many ultrasound-guided minimally invasive procedures. Here, a method for localizing the spatial position of a needle tip relative to the ultrasound imaging probe is presented.

基于光纤超声接收机的三维超声针尖跟踪

Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. ...