Double-layer stretchable composite conductive graphene-hydrogel with wide-range linear sensing and thermal-humidity management for health monitoring

Abstract

Laser-induced graphene (LIG) is widely used in stretchable electrical conductors due to its excellent properties and low manufacturing cost. However, there is usually a mechanical mismatch or poor interface effect between LIG and the flexible substrate, and LIG will inevitably crack when stretched, which leads to LIG-based stretchable conductors usually have poor operating range, linearity and sensitivity stability. In this study, a double-layer stretchable composite conductive (DSCCGH) was prepared based on laser-induced MXene-decorated graphene (LIMG), with LIMG transferred to the hydrogel using a repeated reversible freeze-thaw method and a biomimetic structural design incorporated. The strong mechanical interlocking between LIMG and the hydrogel, along with the graphene-coated MXene derivative TiO2 providing additional electrical pathways when LIG’s conductive networks are disconnected, allowed this DSCCGH to achieve wide-range sensing linearity (0–366%, R2 = 0.9948) and stable sensitivity. This setup enabled stable and reliable muscle movement and pulse monitoring. Furthermore, biomimetic structural design imparts the DSCCGH with perspiration and cooling functions, enhancing comfort and wearability for outdoor exercise. This innovative design provides significant potential for future developments in wearable electronics and human-computer interaction fields.