Wireless and Self‐Powered Wearable Pressure Sensors Based on Chitosan for Artificial Mechanoreceptors

Abstract Touch is key to perception, feeling, and interaction within the social environment. Emulating these sensory capabilities toward intelligent human‐like robots and prosthetics can be achieved by integrating sensor arrays, including pressure, temperature, strain, and humidity, spatially distributed in the human skin, mimicking somatosensory functions. However, existing sensor technologies are not environmentally sustainable due to their non‐biodegradable constituent materials, generally requiring bulky power sources incompatible with wearables. To address these challenges, this study presents a lightweight, flexible, and self‐powered dynamic pressure sensor platform, emulating the functionality of type‐II mechanoreceptors inside the skin, using chitosan biopolymer. A biodegradable pressure sensor is fabricated using a thin composite film of chitosan doped with different compositions of Zinc Oxide (ZnO) nanoparticles (NPs) as the active piezoelectric layer embedded between copper electrodes. The 15 wt.% chitosan‐ZnO composite‐based sensor demonstrates superior pressure and frequency sensitivities of 70.71 mV/kPa and 471.43 mV Hz −1 with excellent cyclic stability and device‐to‐device repeatability compared with pure chitosan‐based pressure sensors. The accelerated biodegradability studies demonstrate that ultra‐thin composite films can completely degrade in slightly acidic deionized water (pH 6.5) in less than 2 h, exhibiting environmental sustainability. Applications include object classification and identification, the detection of hand and finger movements, gesture recognition, and wireless data transmission.