Discharge-induced wireless nanogenerator for energy harvesting and directional wireless power transfer with over 90% efficiency

Abstract

With the increasing challenges of power supply for numerous sensors widely distributed on the Internet-of-Things, triboelectric nanogenerator (TENG) becomes a potential distributed power solution by harvesting mechanical energy from the ambient environment. However, energy output of traditional wired TENGs was largely dissipated by discharge effect, resulting in a low energy transfer efficiency. Here, we proposed a paradigm-shift discharge-induced wireless nanogenerator (DWNG) for wireless power transfer (WPT) by utilizing the energy dissipated by triboelectric discharge. With low matching impedance, the DWNG demonstrated wireless mechanical energy harvesting with energy transfer efficiency of 92.707%, which is far higher than that of the wired output energy of 27.775%. By investigating the spatial distribution of the discharge-induced signal strength, we demonstrated that the wireless energy was concentrated around the electrodes, and the directional WPT can be realized by additional transport electrodes with low energy loss. DWNGs with both solid/solid and solid/liquid interfaces were demonstrated, with the feature of penetrating through bio-tissues, suggesting the capability of DWNG for high-efficiency wireless mechanical energy harvesting and direction WPT in various scenarios.