High-output Flexible Ring-structure Triboelectric Nanogenerators for Wearable Electronics and Sports Monitoring

Abstract

With the gradual miniaturization and functionalization of electronic devices, wearable electronic devices have attracted more and more attention. Triboelectric nanogenerator (TENG) based on triboelectricity and electrostatic induction coupling effect has been widely used in harvesting biomechanical energy of the surrounding environment, and convert it into electrical energy efficiently for wearable electronic devices. Herein, a high-output flexible ring-structure TENG (FR-TENG) is demonstrated, including sponge-like porous polydimethylsiloxane (PDMS) as the triboelectric layer and organic flexible hydrogel electrodes replacing the metal electrodes, which has a good stretchability. For convenience, normal film-based contact-separation TENG is used to test the performance of porous PDMS and hydrogel electrodes to prepare FR-TENG with excellent performance. Sponge-like porous PDMS is prepared by mixing deionized water and PDMS, and exhibits excellent tensile properties than pure PDMS. The proportion of deionized water will signiffcantly affect the morphology of the PDMS film and the output performance of TENG. The maximum output property is further improved by optimizing the concentration of deionized water, an open-circuit voltage (V<inf>OC</inf>) of 100 V and a short-circuit current (I<inf>SC</inf>) of 7.5 &#x03BC;A are achieved by the champion device with deionized water concentration of 7.5 wt&#x0025;. Meanwhile, the open circuit voltage of TENG with the hydrogel as the electrode is more than 1.5 times that of the metal silver electrode. The sports monitoring protective elastic band based on FR-TENG is designed for monitoring human motion data and preventing people&#x2019;s physical injury to protect human health. The application of this band is monitoring various muscle indicators of the human body and alerting injury risk demonstrated during daily fitness exercises. This work presents an effective approach towards health monitoring, self-powered system and human-machine interaction.