High‐Performance Biomechanical Energy Harvester Enabled by Switching Interfacial Adhesion via Hydrogen Bonding and Phase Separation

Abstract

Dramatic advances in wearable electronics have triggered tremendous demands for wearable power sources. To mitigate the impact of CO2 emission on the environment caused by energy consumption, biomechanical energy harvesting for self‐powered wearable electronics offers a promising solution. The output power of devices largely relies on the surface charge density, where adhesion interfaces generate a higher amount than nonadhesion counterparts, yet unfavorable for wearable devices due to the large detachment force required. Thus, sustaining high surface charge density in an adhesion‐free interface represents a major challenge. Herein, by leveraging intermolecular interactions and solvent evaporation induced phase separation, a nonadhesion interface is successfully realized, minimizing the interfacial adhesion from 20 to 0 kPa. Importantly, benefiting from the induced nano/microscale topography upon phase separation, comparable surface charges are generated at the interface. Consequently, a high‐performance flexible biomechanical energy harvester featuring a record high peak power density of 20.5 W m‐2 Hz‐1 at low matching impedance of 1 MΩ is achieved under a low biomechanical input force of 5 N. The device can power small electronics by harvesting regular or intermittent biomechanical energy and illuminate light‐emitting diodes wired/wirelessly. This work provides a facile strategy for interfacial engineering toward efficient energy harvesting.

Solid-state, liquid-free ion-conducting elastomers: rising-star platforms for flexible intelligent devices

“…To boost the output electrical performance, one of the effective approaches is to tailor the properties of the ion-conducting elastomer and electrification material for amplifying the surface change transfer. 166 A self-adhesive PEO-based ion-conducting elastomer could be seamlessly assembled on the surface of a silicone rubber tribolayer with high surface charge density for the fabrication of a high-performance flexible TENG, exhibiting an open circuit voltage of 197 V and instantaneous power density of 2.3 W m −2 . 167 Another feasible strategy to improve the output electrical performance is to further intensify the ionic conductivity of liquid-free elastomers.…”

Advances in magnetic-assisted triboelectric nanogenerators: structures, materials and self-sensing systems

“…As the direct carriers, the tribo-materials are the crucial determinant of the applicability of TENGs [139][140][141][142]. Magnetic-assisted materials have emerged as a promising avenue for enhancing the performance and functionality of TENGs.…”

Textile electronics for wearable applications

“…Fiber-based devices have been extensively researched for energy harvesting from environment and human motion with enormous energy harvesting devices collecting photovoltaic [228], TE [229,230], piezoelectric, triboelectric [231], and moisture-electric [232] energy. Textile products, especially clothing covering large surface area of human body, have good opportunity of exposure to the indoor and outdoor light to absorb the photons from man-made light sources or solar radiation.…”