SGER: Scaling Down Mechanically Driven Fluidic Self-Assembly

摘要CTS-0426779 S。流体自组装（FSA）是一种令人兴奋的制造微观组件的新方法，包括在硅上集成电子，机械和光学器件，或将硅电子芯片集成到塑料或其他基板上。该过程自动工作，使用随机流体传输，允许在几分钟内放置大量设备。最近，工业界已经利用FSA来大幅降低射频识别（RFID）标签的成本，RFID标签是一种用于自动管理产品、供应品和设备流动的新兴技术。 大众媒体最近报道了沃尔玛、国防部和许多其他机构敦促在供应链中广泛采用RFID技术的报道。 RFID标签的大规模采用的限制因素之一是它们的成本，由于材料成本（大约mm 3的Si）和拾取和放置机器人组装的制造成本，以每个标签的美元来测量。 FSA可以帮助解决这两个问题，同时消除机器人组装，并允许更小的标签的精确组装。 这项工作的智力价值是考虑到当缩小标签的大小时遇到的新问题。 这些包括一系列新的表面力，这些力可能变得重要，而体积力，如浮力和惯性变得不那么重要。 此外，随着布朗运动的增加，对于较小尺寸的标签，悬浮液体的原子性质变得明显。 FSA，至少在大规模上，对于梯形标签的浓缩悬浮液是最有效的。 为了研究FSA在浓缩悬浮液中的动力学，将使用两类RFID标签替代品进行实验，一类是透明的，折射率与流体的折射率相同，另一类是不透明的。 因此，悬浮液将看起来透明，但仍显示浓缩悬浮液的动态。 在工作顺利完成后，工作的广泛影响将显而易见。 更便宜的方法来跟踪消费者和国防产品将导致经济效率，这将有利于我们的社会。 此外，减少运输和储存效率低下将有利于环境。超低成本RFID标签的可用性是这种进步的推动力，但需要开发新的信息技术来管理大量的新信息存储，并推动我们的国家网络基础设施从计算机网络转变为计算机和所有跟踪对象的网络。 所提出的实验的新奇在于，它们将使用与FSA制造工艺相关的范围内的悬浮液体积分数。此外，这项工作的探索性质在于找到折射率与固体材料相同的溶剂的正确组合，该固体材料可以微加工成与RFID标签制造过程相关的形状。一旦这些问题得到解决，一系列改变固体分数、颗粒尺寸、流速等的实验，将被执行。 FSA在小尺度上的动态将变得明显。 这项工作的成功结束将导致一个更大规模的调查与实际的制造参数的FSA的动态。

AbstractCTS-0426779S. Wereley, Purdue UniversityFluidic self-assembly (FSA) is an exciting new method for manufacturing microscopic assemblies, including integration of electronic, mechanical, and optical devices on silicon, or of silicon electronic chips onto plastic or other substrates. The process works automatically, using random fluidic transport, allowing the placement of very large numbers of devices in minutes. Recently, industry has exploited FSA to lower dramatically the cost of radio frequency identification (RFID) tags an emerging technology for managing the flow of products, supplies and equipment automatically. The popular press has recently featured reports of WalMart, the DOD and many others urging widespread adoption of RFID technology in the supply chain. One of the limiting factors for widescale adoption of RFID tags is their cost which is measured at dollars per tag, due to the material costs (approximately mm3 of Si) and manufacturing costs from pick and place robotic assembly. FSA can help solve both of the problems by simultaneously eliminating the robotic assembly and allowing precision assembly of much smaller tags. The intellectual merit of this work is the consideration of the new problems that are encountered when scaling the size of the tag down. These include a host of new surface forces that can become important while volume forces, such as buoyancy and inertia become less important. Furthermore, the atomistic nature of the suspending liquid becomes apparent for the smaller size tag with the increase of Brownian motion. FSA, at large scales at least, is most efficient with a concentrated suspension of the trapezoidal tags. In order to study the dynamics of FSA within a concentrated suspension, experiments will be conducted using two classes of RFID tag substitutes, one that is transparent with a refractive index identical to that of the fluid and one that is opaque. The suspension will thus appear transparent but still display the dynamics of a concentrated suspension. Upon the successful completion of work, the broader impacts of the work will be apparent. Cheaper ways to track consumer and defense products will lead to economic efficiencies that will benefit our society. Further, reducing shipping and storage inefficiencies will be good for the environment. The availability of ultra low-cost RFID tags is an enabler of such advances, but new information technology techniques will need to be developed to manage the vast new stores of information and drive a transformation of our national cyberinfrastructure from a network of computers to a network of computers and all tracked objects.. The novelty of the proposed experiments is that they will use suspension volume fractions in a range that is relevant to the FSA manufacturing process. Further, the exploratory nature of the work resides in finding the right combination of a solvent whose refractive index is identical to a solid material that can be microfabricated into shapes relevant to the RFID tag manufacturing process. Once these problems are tackled, a series of experiments varying solid fraction, particle size, flow rate, etc., will be performed. The dynamics of FSA at small scales will become apparent. Successful conclusion of this work will lead to a larger-scale investigation into the dynamics of the FSA with practical manufacturing parameters.