Towards Practical Triboelectric Nanogenerator for Mechanical Energy Harvesting and Self-powered Sensing

Abstract

Triboelectric nanogenerator (TENG) offers a promising solution as a decentralised energy source to sustainably power the ever-growing mobile electronics. TENG’s characteristics such as high output, versatile working modes and broad material availability have made it viable but still there are a few issues that limit practical applications of TENG. This thesis aims to tackle some of the practical limitations of TENGs to be used as wearable energy harvesters or self-powered sensors. Firstly, to address the poor stretchability of TENG with rigid metal / carbon electrodes for wearable applications, a soft and highly stretchable solid polymer electrode (SPE) based on biocompatible PVA infused with ionically conductive ingredient was developed as the TENG electrode. The use of SPE endows the TENG with high stretchability, superb transparency, environmental stability, and enhanced electrical output. Then the requirement of complex power management system of conventional TENG with AC output was simplified with a new design of DC-TENG boosted by a dual-breakdown mechanism. The DC output could be directly utilized by small electronics without the need of rectifiers, thus reducing complexity and energy loss. Lastly, for TENG-based sensors, to overcome the errors caused by TENG output variations under changing environment, a new method of extracting sensing signals independent of intrinsic TENG output variations is proposed. This research has yielded several important scientific contributions in the device design, optimisation and application of TENG. These findings provide new opportunities to improve TENGs in terms of wearing comfort, system complexity and sensing reliability, thus greatly enhancing the practical application of TENGs in real-life scenarios.