In-Situ Controllable Fabrication and Performance of Laser-Induced Graphene Flexible Sensors for Human Motion Monitoring

Graphene-based resistive sensors exhibit excellent sensing performance, but face challenges in terms of uniformity, stability, and large-scale fabrication. To address these issues, in this study, we blade-coated a PI/PDMS precursor on the fabric surface and constructed graphene via in situ laser induction, thereby effectively improving the preparation efficiency and stability of graphene. Meanwhile, the influence of the PI-to-PDMS ratio on the performance of the laser-induced graphene resistive sensor was investigated. It was found that at a PI-to-PDMS ratio of 1:3, the formed graphene showed the fewest defects and the highest graphene proportion, which originated from its good fluidity, compatibility, and crosslinking density. Experimental results demonstrate that the sensor exhibits favorable sensing performance, with a linearity of 0.99 and a sensitivity of 8.64 within the 10–20% strain range of Sample 2, along with repeatable stability over 2000 cycles, meeting the requirements of skin-friendly contact and highly stable motion monitoring for human joints. This study provides a reference for the efficient and rapid construction of graphene-based resistive sensors and shows considerable application potential.