Abstract: A new type of tea residue powder based triboelectric nanogenerator (TRP-TENG) was developed, and a smart wind monitoring device was developed based on it. During the experimental process, tea residue ultrafine powders with different degrees of fermentation were used as friction film materials to prepare different triboelectric nanogenerators. The differences in electrical output performance were tested and compared on a horizontal reciprocating stamping platform to find the optimal material for TRP-TENG and to optimize the device. On this basis, further testing and analysis were conducted on the optimized TRP-TENG in terms of frequency response, load characteristics, sustainability, and power supply capacity to evaluate its feasibility for application in wind monitoring devices. The experimental results show that the TRP-TENG developed with white tea residue as the material had the best electrical output performance, with an open-circuit voltage and short-circuit current of 9.1 V and 4.4 µA, respectively, and had a certain degree of stability. The contents of tea polyphenols and catechins in white tea residue were relatively high, while the contents of tea pigments were low. The corresponding TRP film had a loose and porous concave-convex surface microstructure, which could effectively increase the contact area and help improve the electrical output performance of TENG. This TRP-TENG could adapt to various vibration frequency working environments, and when the external resistance was 50 MΩ, the electrical output power reached 108.0 µW. At a driving frequency of 3 Hz, it could simultaneously light up 5 series connected commercial LED lights, and it could make the electronic timer work continuously for 15 s after charging the 10 µF capacitor for 5 min. In terms of application, a self-powered wind monitoring device was developed based on four series of connected TRP-TENG components. The test results show that this device has a significant response sensitivity to wind speed and can be applied to smart agriculture systems.

Key words: tea residue, triboelectric nanogenerator, energy collection, self-powered sensor, smart agriculture