(Invited) Ultralight Triboelectric Nanogenerators for Portable Self-Charging Power Unit and Self-Powered Sensing Platform

Abstract

With rapid development of portable electronic devices and systems, mandatory requirements of portable, lightweight, and significantly sustainable power sources have attracted huge attention. Li-ion batteries or other energy storage devices are commonly used as a stable power supply for driving these electronic devices with small-scale energy consumption at the μW to mW level. Nevertheless, in modern personal electronics, batteries are usually the largest or heaviest component in the whole device, and moreover, the crucial problem of batteries is their limited lifetime and thus their need to be charged or replaced frequently. To conquer this problem, self-powered systems as integrated by an energy harvester and an energy storage device has been proposed and developed to simultaneously harvest and store ambient energy in the form of electricity, which opens potentials for sustainable and maintenance-free applications. Here, we report a ultralight cut-paper-based self-charging power unit (PC-SCPU) that is capable of simultaneously harvesting and storing energy from body movement by combining a paper-based triboelectric nanogenerator (TENG) and a supercapacitor (SC), respectively. Utilizing the paper as the substrate with an assembled cut-paper architecture, an ultralight rhombicshaped TENG is achieved with highly specific mass/volume charge output (82 nC g−1/75 nC cm−3) compared with the traditional acrylic-based TENG (5.7 nC g−1/5.8 nC cm−3), which can effectively charge the SC (∼1 mF) to ∼1 V in minutes. PC-SCPU is demonstrated as a sustainable power source for driving wearable and portable electronic devices such as a wireless remote control. To further enhance the output performance of TENG for extending the possible applications in portable electronic devices, we also report an ultrahigh output power of whirligig-inspired TENG (Wi-TENG) designed according to an antiqueue whirligig toy that is capable of converting low-frequency pulling motion into a high-frequency rotation. It shows that the rotor in the Wi-TENG achieves a maximum speed of 11,250 rpm. Ultrahigh charge transfer quantity of ~310 μC and output power of 40.18mW are obtained by per pulling of Wi-TENG. Moreover, a maximum short circuit current of 317 μA and a constant open-circuit voltage peak value of 153 V can be generated by the Wi-TENG, which can rapidly charge a commercial capacitance (100 μF) to ~14 V within 10 s. After power management, this Wi-TENG is successfully demonstrated as a portable sustainable power source for driving a commercial blood glucose meter.