Self-Powered Dual-Mode Amenity Sensor Based on the Water-Air Triboelectric Nanogenerator.

A water-air triboelectric nanogenerator (WATENG) is presented for CO sensing application. During the operation of WATENG, two independent charge transfers can be used to characterize the effect of force and humidity, respectively. Thus, the structure of WATENG provides a capability to eliminate these two major interferences in a triboelectric self-powered sensor. With the aid of the polyethylenimine (PEI) coating, WATENG can be used for CO sensing in both static and dynamic conditions. In static condition with a stable CO concentration, the CO sensing is characterized with respect to different relative humidity, and the sensing range can be up to 6000 ppm. In dynamic CO sensing of a pulse gas spray, due to the fast recovery of PEI surface reaction, the sensing range of dynamic situation can be broadened to 30,000 ppm. The self-powered and portable feature of WATENG is preferable as a self-powered amenity sensor for the construction of internet of the things (IoT) sensor networks in the future.