Self-powered online practical machine condition monitoring and wireless communication achieved on integrated, efficient, and durable triboelectric nanogenerator

Triboelectric nanogenerator (TENG) can effectively scavenge ambient mechanical energy with cost, weight, and effectiveness advantages despite critical issues of TENG such as integration to complex components, low current output, and durability. In this work, we designed an adaptive TENG on a mechanical shaft for harvesting rotational energy which can easily assemble and disassemble. The proposed TENG presents an excellent performance for a wide range of rotational speeds (0–2000rpm) and delivers a high power of up to about 80mW (a high short circuit current of 3mA) for a size of 216 cm 3, which is high enough for many types of machine condition monitoring purposes. The designed TENG has been evaluated under the noncontact mode of operation within a 0–0.5mm gap between TENG films. The TENG demonstrates excellent electrical stability of 99% without surface wear under noncontact mode within the whole test period for continuous operation of 420,000 cycles. The contact mode with a contact pressure of 0.76 Pa results in 90% electrical stability and apparent surface degradation. Moreover, it is demonstrated that the proposed TENG can power a wireless vibration sensor (60 mW) within 10 minutes energy harvesting for 9 seconds to send data via Bluetooth to a smartphone at up to 30 m, and a wireless temperature sensor (1.2 mW) in real-time for machine condition monitoring.