Armadillo-inspired ultra-sensitive flexible sensor for wearable electronics

Abstract

Flexible sensors are receiving growing attention as a valuable technology in application areas such as wearable electronics, soft robotics and e-skin. Unfortunately, most flexible sensors generally suffer from low sensitivity, narrow application range and single detection function. Herein, we present an uneven deformation strategy inspired by armadillo skin to construct ultra-sensitive flexible sensors. ASR-CLNS sensor consists of a silicone rubber substrate imitating the armadillo skin (ASR) and a continuously laminated conductive network (CLN). Mechanical deformation-induced stress concentration substantially contributes to ultra-high sensitivity. Noteworthily, the non-uniform substrates have specific stress concentration responses in different tensile directions, and the stretch sensitivity can be easily adjusted by microstructure customization or simply changing the sensor placement angle, which enables it to meet the detection requirements of more scenarios. Simultaneously, the laminated structure of the CLN endows the sensor pressure sensitivity, which allows sensors to be used to detect small pressures such as human breathing. Additionally, CLN demonstrated fast heat transfer capability, which can effectively improve the thermal management properties of composites. In short, this work provides an unexplored strategy to develop tunable/ultra-high sensitivity and multifunctional flexible sensor devices.