Nanoelectronics Flexible substrate applications


Functional flexible substrate devices and cables based on polyimide cabling technology are a feasible, reliable and inexpensive solution for many biomedical diagnostic tools. Polyimide is chosen here due its low dielectric constant, flexibility, excellent dimensional stability, low outgassing and non-contaminating properties and exceptional mechanical strength.

The general platform being developed in this project consists of a bendable, adaptable system with stress/strain, temperature and humidity sensors that can be tailored to specific artificial skin, external sensing of body vital signs and implantable bone integrity monitoring applications. The overall fabrication process comprises (a) spin-coating polyimide atop 8-inch-diameter silicon wafers and curing, (b) defining the array sensing elements, (c) coating the resulting sample with another polyimide layer for passivation, (d) patterning the polymer layers using standard optical lithography and oxygen plasma etching and (e) peeling the devices off the silicon substrates. The substrates act simply as carriers to allow compatibility with cleanroom tools.