Microenvironment‐Engineered Piezoionic Hydrogel Nanogenerators for Enhanced Energy Harvesting and Sensing

Abstract

ABSTRACT The demand for advanced materials capable of both efficient energy harvesting and high‐performance sensing has spurred research on piezoionic hydrogels. However, their low current and voltage outputs remain a bottleneck. In this study, an innovative piezoionic hydrogel nanogenerator (PHNG) based on polyacrylamide (PAM) hydrogel is developed using a microenvironment‐engineered strategy. By precisely modulating the internal acid‐base environment and incorporating optimized bubble structures, the device achieves a remarkable current output of up to 610.5 μA, which significantly outperforms most reported PHNGs. Moreover, the working principle of the microenvironment‐engineered PAM hydrogel under mechanical stress is systematically investigated. The enhancement in current output is primarily attributed to the modulation of the internal acid‐base environment, which increased the disparity in ion migration rates, and the incorporation of bubbles that induced lateral stress, enhancing ion mobility. The optimized PHNG exhibits high sensitivity (37.657 μA kPa −1 ), superior stretchability and good stability. Finally, an intelligent PHNG‐based electronic chessboard is developed to showcase the device's advanced sensing capabilities. This research provides new strategies for boosting PHNG performance and broadens its application prospects.