Wearable fabric-based ZnO nanogenerator for biomechanical and biothermal monitoring

Abstract

Wearable devices that can mechanically conform to human skin are a necessity for reliable monitoring and decoding of biomechanical activities through skin. Most inorganic piezoelectrics, however, lack deformability and damage tolerance, impeding stable motion monitoring. Here, we present an air-permeable fabric-based ZnO nanogenerator with mechanical adaptivity to diverse deformations for wearable piezoelectric sensors, collecting biomechanical health data. We fabricate ZnO nanorods incorporated throughout the entire nylon fabric, with a strategically positioned neutral mechanical plane, for bending-sensitive electronics (2.59 μA mm). Its hierarchically interlocked geometry also permits sensitive tactile sensing (0.15 nA kPa^-1). Various physiological information about activities, including pulse beating, breathing, saliva swallowing, and coughing, is attained using skin-mounted sensors. Further, the pyroelectric sensing capability of a mask-attached device is demonstrated by identifying specific respiratory patterns. Our wearable healthcare sensors hold great promise for real-time monitoring of health-related vital signs, informing individuals' health status without disrupting their daily lives.

Keywords: Biomonitoring; Fabric-based ZnO nanogenerator; Pieozoelectric energy harvesting; Pyroelectric energy harvesting; Wearable healthcare sensor.