Scalable Wearable and Biocompatible Temperature Sensor: Integrating Laser‐Reduced Graphene Oxide on Chitosan‐PEG Membranes

ABSTRACT Flexible, cytocompatible, scalable temperature sensors are essential for bioelectronic devices. Here, a flexible sensor is fabricated using a chitosan–poly(ethylene glycol) (CS–PEG) matrix embedded with laser‐reduced graphene oxide (LrGO). Laser‐assisted reduction enhances conductivity and generates a stratified, porous microstructure that supports efficient percolation while maintaining flexibility. The sensor shows a stable, highly sensitive thermal response, with a temperature coefficient of resistance (TCR) of and a sensitivity of across . Impedance spectroscopy shows that the resistive configuration at yields an almost linear response (R ² = 0.996), while capacitive behavior and humidity variations ( RH) induce minor impedance changes (<15%). Under a ‐‐ step, the device shows reversible electrical changes, with a response time of , recovery of , minimal hysteresis (), and stable performance over . Bending tests up to strain for 200 cycles produce moderate resistance variation (R/R ₀ ≤ 1.88), confirming mechanical robustness. On‐skin measurements from to show a resistance decrease. Charge‐transport analysis agrees with Mott's hopping model. Cell‐culture assays confirm high viability (). The scalable, solvent‐free, metal‐free fabrication highlights the CS–PEG–LrGO sensor as a promising platform for wearable biosensing.