Progress of biomechanical energy harvesters for wearable electronic applications

Abstract The rapid development of advanced manufacturing technologies in micro-electro-mechanical system (MEMS) fields has promoted the advance in wearable electronics. Among them, wearable biomechanical micro-energy harvesters have attracted much attention in recent years to meet the unique power supply demands of wearable electronics serving as sustainable power sources. In the meanwhile, they also have been successfully demonstrated to be either self-powered sensors or other functional devices for wearable electronic applications. Herein, we overview the state-of-the-art of biomechanical micro-energy harvesters for wearable electronic applications, including the summary of working principles and structural configurations of biomechanical micro-energy harvesters. In detail, three promising technologies for biomechanical micro-energy harvesting are studied, i.e. electromagnetic effect, piezoelectric effect, and electrostatic effect. As for the structural configurations, two essential factors to affect the properties of biomechanical micro-energy harvesters are emphasized, i.e. new materials, and advanced manufacturing technologies. For wearable application scenarios, fiber/fabric-based materials and biodegradable/ecofriendly materials are investigated. For advanced manufacturing technologies, micro/nano fabrication technologies for precise fabrication and large-scale fabrication technologies for mass fabrication are summarized. Moreover, we review the wearable electronic applications of biomechanical micro-energy harvesters for powering, sensing, and actuating, respectively, which reveals the feasibility of constructing the smart wearable microsystems based on the abundant function of biomechanical micro-energy harvesters. Finally, we conclude the review and discussed the future development trends of biomechanical micro-energy harvesters for wearable electronic applications.