EAGER: Cut-and-Seam Manufacturing of Sensor Meshes for Perfusible Electronics

这项探索性研究的早期概念资助（EAGER）支持将电子设备连接到光纤阵列的研究，将多孔网格引入最初为固体表面设计的电子制造系统。传感器芯片将应用于蜘蛛状的微机电（MEMS）中间层，这种中间层可以附着在网状纤维上。网状封装的好处是，它允许传感器放置在新的、技术上重要的流动流体环境中，包括细胞生长支架、用于化学制造的膜反应器和冷却剂冲洗电子设备。支撑材料比传统的电子电路板更柔软，研究人员将研究如何连接可变形材料，使电子连接跨越接缝，而无需精确对齐。切缝式制造有利于空气处理器和呼吸面罩等过滤系统，这些系统必须适合独一无二的无间隙三维（3D）表面。这个项目可以导致一种新的电子制造方法，设计用于多孔和纤维材料。提出了一种工作传感器网格的三维装配策略，并对其成功进行了评价，同时也对其在接缝交叉和信号识别方面的局限性进行了评价。本项目还为纺织工程、机械工程和电气工程专业的本科生提供研究和培训机会，并为参与者提供有关MEMS和传感器的推广材料。这项EAGER研究的目标是在三个挑战上取得进展：1)MEMS和纤维之间低电阻接触的可扩展转移工艺，2)在灌注环境中操作的足够机械强度，以及3)纺织品制造中松散对齐公差的接缝可寻址性。该项目研究了一种从供体表面释放器件的新热方法。该装置的拉离力是在流动条件下表征的，电接触是使用探针站测量的。该方法是在整流缝带中使用芯片级二极管，以防止接缝处短路。最后，使用具有唯一ID号的温度芯片，传感器网格将被热源扫描，传感器信号用于识别接缝上的加热位置。这个跨学科的项目通过提高对设备到纤维连接的电气和机械性能及其对布局的依赖的理解，将微转移印刷转化为多孔和纤维基板。微转移芯片印刷技术现在已经取得了商业上的成功，但这些方法是为连续的、无孔的、具有可预测粘附接触面积的表面而设计的。该项目定义了接缝交叉点的信号完整性问题，这是制造可伸缩电子系统中一个日益重要的话题，而标准化连接器技术尚未可用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This EArly-concept Grant for Exploratory Research (EAGER) award supports research on attaching electronics to fiber arrays, bringing porous meshes into an electronics manufacturing system originally designed for solid surfaces. Sensor chips will be applied to spider-like microelectromechanical (MEMS) interposers that grip onto mesh fibers. The benefit of mesh packaging is it allows sensors to be placed into new, technologically important environments with flowing fluids, including cell growth scaffolds, membrane reactors used in chemical manufacturing, and coolant-flushed electronics. The supporting materials are softer than conventional electronic circuit boards, and the researchers will investigate how to join deformable materials making electronic connections across seams without precise alignment. Cut-and-seam manufacturing benefits filtration systems such as air handlers and respiratory masks that must fit one-of-a-kind three-dimensional (3D) surfaces without gaps. This project can lead to a new electronics manufacturing method designed for porous and fibrous materials. It presents a strategy for 3D assembly of working sensor meshes and evaluates its success as well as limitations for seam crossing and signal identification. This project also provides research and training opportunities for undergraduates in textile engineering, mechanical engineering, and electrical engineering, and outreach materials for participants to learn about MEMS and Sensors.The goal of this EAGER research is to make progress on three challenges: 1) scalable transfer processes for low-resistance contacts between MEMS and fibers, 2) sufficient mechanical strength for operating in perfused environments, and 3) addressability across seams made with the loose alignment tolerances of textile manufacturing. The project investigates a new thermal method for device release from a donor surface. The devices’ pull-off force is characterized under flow, and electrical contact is measured using a probe station. The approach is to use chip-scale diodes in a rectifying seam tape that prevents shorting at seams. Finally, using temperature chips with unique ID numbers, the sensor meshes will be scanned with a heat source and the sensor signals are used to identify the heated location across a seam. This interdisciplinary project transforms microtransfer printing to porous and fibrous substrates by improving understanding of device-to-fiber junctions’ electrical and mechanical properties and their dependence on layout. Microtransfer chip printing techniques are now seeing commercial success, but these methods are designed for continuous, non-porous, surfaces with predictable adhesion contact area. This project defines the problem of signal integrity at seam crossings, an increasingly important topic in manufacturing stretchable electronic systems where a standardized connector technology is not yet available.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.