Multifunctional strain sensor with adjustable conductive network for wearable applications

Abstract

Wearable sensors based on nanomaterials have recently elicited keen research interest and potential for a new range of flexible devices. This paper presents a simple method for the preparation of laser‐induced porous graphene (LIG) and discusses its application in monitoring human vital signs. LIG formed on a polyimide (PI)/polydimethylsiloxane (PDMS) composite material exhibits inherent high stretchability (over 30%), eliminating the need for transfer processes used in LIG prepared by laser scribing on PI films. LIG/CuSO4 composite materials, with different concentrations of Cu particles, show tunable mechanical and electronic properties based on laser‐induced graphene. The fabricated LIG demonstrates good cyclic stability and a nearly linear resistance response to tensile strain, making it suitable for wearable electronic devices, the maximum strain value and linear response to applied strain from 3% to 79%. The sensor exhibits a fast response time and high sensitivity, enabling real‐time detection of human pulse, joint motion, and complex dynamics. The multifunctionality advantages of LIG flexible sensor offer potential applications in next‐generation wearable electronics.