Contact-electrification enabled water-resistant triboelectric nanogenerators as demonstrator educational appliances

Abstract Triboelectric nanogenerators (TENG) work on the principle of tribo and contact electrification, which is a common effect observed in daily life. TENGs are moving closer to commercialization, particularly for small scale energy harvesting and self-powered sensing. The toys and games industry has attracted a huge audience recently with the introduction of digital toys. In this paper we embedded TENGs to power up a toy and operate during its specific application. We have modified two potential electronic demonstrator applications using TENG for lobster toy (LT-TENG) and stress ball (SB-TENG) device. The LT-TENG device generates a maximum electrical response of 60 V/ 2 µA, with a power of 55 µW and power density of 0.065 µW/m2 at a load resistance value of 10 MΩ. Similarly, the SB-TENG device made of aluminum and PDMS as the triboelectric layers generates a maximum electrical output response of 800 V and 4 µA peak to peak current with an instantaneous power of 6 mW and a power density of 3.5 mW/m2 respectively at a load resistance of 10 MΩ. In addition, the layers of the TENGs are packed with polyethylene to maintain the performance of the nanogenerator under harsh environmental conditions, especially with humid environments. The water resistance studies proved that the packed SB-TENG is impervious to water. The LT-TENG device is accompanied by four LEDs, and the device lights up upon actuating the handle. The stress ball is connected with the measuring instrument to record the quantity of force at which the stress ball is pressed. The adopted approach paves the way to convert these traditional toys into battery-free electronic designs and its commercialization.