High Sensitivity, Wide Response Pressure Sensor by Bioinspired Structure

ABSTRACT High‐performance flexible pressure sensors have demonstrated significant promise in electronic skins, energy harvesting, soft robotics, and other applications. However, achieving concurrent optimization of sensitivity and a broad pressure response range remained challenging, leading to limitations in detection thresholds, sensing range, and mechanical robustness. In this work, gradient stress hydrogels were prepared through a limited domain swelling method. It was made up of “soft” hydrogel (Poly (hydroxyethyl acrylate ‐co‐ acryloyloxyethyl trimethyl ammonium chloride) (HD 20 )) and “hard” hydrogel (Poly hydroxypropyl acrylate (HPA 50 )). “Soft” hydrogel provided high electrical conductivity (1.0510 S/m) and high sensitivity (4.7271 MPa −1 ), whereas “hard” hydrogel offered a wide sensing range (from 0.000486 to 1.17 MPa). Additionally, it could be applied to various material interfaces (glass, plastic, metal, polytetrafluoroethylene, silicone rubber, skin) due to ─OH/N + groups and low temperature environments (−14 °C). And it demonstrated outstanding cycle stability and the capacity to identify various strains. This facile and effective method was useful to design and preparing highly sensitive pressure sensors at a wide pressure working range.