Professor Lizhi Xu of the Department of Mechanical Engineering and his team worked on the research for the topic “A high-current hydrogel generator with engineered mechanoionic asymmetry”. The research findings were recently published in Nature Communications on February 19, 2024.
Details of the publication:
A high-current hydrogel generator with engineered mechanoionic asymmetry
Hongzhen Liu, Xianglin Ji, Zihao Guo, Xi Wei, Jinchen Fan, Peng Shi, Xiong Pu, Feng Gong, Lizhi Xu, article in Nature Communications
https://www.nature.com/articles/s41467-024-45931-7
Abstract
Mechanoelectrical energy conversion is a potential solution for the power supply of miniaturized wearable and implantable systems; yet it remains challenging due to limited current output when exploiting low-frequency motions with soft devices. We report a design of a hydrogel generator with mechanoionic current generation amplified by orders of magnitudes with engineered structural and chemical asymmetry. Under compressive loading, relief structures in the hydrogel intensify net ion fluxes induced by deformation gradient, which synergize with asymmetric ion adsorption characteristics of the electrodes and distinct diffusivity of cations and anions in the hydrogel matrix. This engineered mechanoionic process can yield 4 mA (5.5 A m−2) of peak current under cyclic compression of 80 kPa applied at 0.1 Hz, with the transferred charge reaching up to 916 mC m−2 per cycle. The high current output of this miniaturized hydrogel generator is beneficial for the powering of wearable devices, as exemplified by a controlled drug-releasing system for wound healing. The demonstrated mechanisms for amplifying mechanoionic effect will enable further designs for a variety of self-powered biomedical systems.