Robust Design of Large Area Flexible Electronics via Compressed Sensing

Abstract

Large area flexible electronics (FE) is emerging for low-cost, light-weight wearable electronics, artificial skins and IoT nodes, benefiting from its low-cost fabrication and mechanical flexibility. How-ever, the low temperature requirement for fabrication on a flexible substrate and the large-area nature of flexible sensor arrays inevitably result in inadequate device yield, reliability and stability. Therefore, it is essential to develop design methodologies for large area sensing applications which can ensure system robustness with-out relying on highly reliable devices. Based on the observation that most signals sensed by body sensor arrays exhibit sparse statistical characteristics, we propose a system design method which lever-ages the sparse nature via compressed sensing (CS). Specifically, we use flexible circuitry to implement a CS encoder and decode the compressed signal in the silicon side. As a system demonstration, we fabricated the temperature sensor array, shift register and amplifier to illustrate the feasibility of the encoder design using carbon-nanotube-based flexible thin-film transistors. To evaluate the improvement of system robustness achieved by the proposed sensing schema, we conducted two case studies: temperature imaging and tactile-sensor based object recognition. With ∼10% sparse errors (due to either device defects or transient errors), we achieved reduction of root-mean-square-error (RMSE) from 0.20 to 0.05 for temperature sensing and boost the classification accuracy from 65% to 84% for tactile-sensing based object recognition.