Nanogenerator Based Full Self-powered Ultraviolet Detection System

Self-powered system is a new kind of functional devices which could convert mechanical energy in the environment into electrical energy for powering themselves. This system has enormous potential applications in the field of environmental monitoring, health monitoring, reconnoitering and biomedicine. Although the nanogenerator-based self-powered system developed fast in recent years, full self-powered sensing system still needs further improvement. In this paper we carried out some work around nanogenerator based full self-powered ultraviolet (UV) detection system, including PVDF/PA11 composite film-based piezoelectric nanogenerator, electrospun nanowire-based triboelectric nanogenerator (TENG), full self-powered UV radiation level detection system and TENG-based self-powered UV photodetector.By using PVDF/PA11 composite film, a piezoelectric nanogenerator with good performance is fabricated. The open-circuit voltage and the short-circuit current of this nanogenerator respectively reach up to 3.2 V and 13.2 uA. As a power source, this piezoelectric nanogenerator can power a commercial light-emitting diode (LED) directly without an energy storage system. Integrating the piezoelectric nanogenerator with a UV sensor, we fabricated a self-powered UV sensor which could detect UV intensity without additional power pack.A new kind of TENG is developed based on electrospun PVDF and PA6 nanowires. This nanogenerator exhibits the remarkable characteristics of easy fabrication, low cost and high output. Its open-circuit voltage and short-circuit current respectively reaches up to 1163 V and 211 μA. The power of this TENG is capable of lighting up as many as 140 commercial LED bulbs. And for the first time we powered a DC motor without an energy storage system by using this TENG.By using the high performance TENG, ZnO nanofiber based UV sensor, LED bulbs, shunt resistors and Zener diodes, we designed and fabricated a full self-powered UV radiation level detection system. By using this equipment, anyone can measure the UV radiation level anytime and take proper steps to protect his skin and eyes. This work not only presents a portable and self-powered UV radiation level detection device to alert people to a possible over-exposure to UV light, but also expands the potential applications of self-powered system to the field of public health.A TENG-based self-powered UV photodetector is fabricated using ZnO and PVDF as friction layers. This device integrates sensing unit with power supply unit and has dual functions. With this TENG-based UV photodetector, UV intensity of 2 nW/cm2 is successfully detected without additional power pack.