Ultra-Broad Linear Range and Sensitive Flexible Piezoresistive Sensor Using Reversed Lattice Structure for Wearable Electronics

Abstract

Flexible pressure sensors have attractedsignificant attentionowing to their broad applicability in wearable electronics and human-machineinterfaces. However, it is still challenging to simultaneously achievea broad sensing range and high linearity. Here, we present a reversedlattice structure (RLS) piezoresistive sensor obtained through a layer-levelengineered additive infill structure via conventional fused depositionmodeling three-dimensional (3D) printing. The optimized RLS piezoresistivesensor attained a pressure sensing range (0.03-1630 kPa) withhigh linearity (coefficient of determination, R (2) = 0.998) and sensitivity (1.26 kPa(-1)) dueto the structurally enhanced compressibility and spontaneous transitionof dominant sensing mechanism of the sensor. It also exhibited greatmechanical/electrical durability and a rapid response/recovery time(170/70 ms). This remarkable performance enables the detection ofvarious human motions over a broad spectrum, from pulse detectionto human walking. Finally, a wearable electronic glove was developedto analyze the pressure distribution in various situations, therebydemonstrating its applicability in multipurpose wearable electronics.