Flexible and Cost-Effective Graphene-Coated Textile-Based Piezoresistive Pressure Sensor on a Paper Substrate for Human Motion Detection and Human−Machine Interfaces

The development of mechanically robust graphene-textile-based pressure sensors remains challenging due to poor adhesion between graphene-based conductive coatings and textile substrates. It often leads to coating delamination, degradation of conductive pathways, and unstable sensing performance under repeated mechanical deformation. Herein, we report a flexible piezoresistive pressure sensor based on a silk sericin (SS)-assisted reduced graphene oxide-coated textile (RGSC) integrated with graphite interdigitated electrodes fabricated on a paper substrate. Unlike conventional synthetic coupling agents, SS serves as a naturally derived bioadhesive interfacial layer that promotes strong interactions between graphene oxide (GO) and textile fibers, enabling enhanced coating adhesion and long-term stability. Fourier transform infrared spectroscopy confirms the formation of intermolecular interactions between sericin and GO, while washing durability and tape-peel tests demonstrate significantly improved coating retention. The sensor exhibits a wide pressure-sensing range of 0−250 kPa with sensitivities of 1.13 and 0.11 kPa −1 in the low- and high-pressure regions, respectively. It also has a low detection limit, low hysteresis, rapid response, excellent repeatability, and robust mechanical durability under repeated bending and cyclic loading. To validate the sensing mechanism, compressive strain analysis, microscopy-assisted structural deformation studies, and equivalent circuit modeling are performed. The results reveal that the sensor response originates from the pressure-induced densification of the conductive textile network and modulation of interfiber and sensing layer−electrode contact resistances. Furthermore, the developed sensor successfully demonstrated wearable monitoring of human motion and physiological signals while also exhibiting compatibility with wireless sensing platforms. This work introduces a bioderived interfacial method for robust graphene integration onto textile substrates and provides a promising route toward mechanically durable and environmentally responsible wearable pressure-sensing systems.