NSF Award
2309482
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.<br/><br/>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.<br/><br/>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.
