Ice-based triboelectric nanogenerator with low friction and self-healing properties for energy harvesting and ice broken warning

In this paper, a new type of ice-based triboelectric nanogenerator (ICE-TENG) has been fabricated to harvest energy in cold weather. Ice is a preferred material for designing TENGs in cold winter, alpine or snowy mountain regions because of its cleanness, environmental protection, abundant reserves, low friction, and self-healing properties. The short-circuit current and voltage can achieve 2.4 mu A and 48 V with 4 mm thickness of ice layer, 30 N loadings, and 5 Hz contact frequency, which can be useful in some practical applications such as lighting LEDs and charging capacitors. The ICE-TENG possesses excellent stability and can reach an output power of 35 mu W under 20 MCI loading resistance. The coefficient of friction between ice and other friction pairs is negligible, and it can even become super-slippery with the coefficient of friction below 0.008. Thus, the wear of the friction pairs is small, which can help TENG to have a long working life. Besides, due to the rapid phase change of ice, the ICE-TENG exhibits a commendable self-healing ability and maintains the original output performance after several damage and repair processes. To simulate the practical applications, a single electrode ICE-TENG driven by walking has been designed for harvesting energy on the ice surface. Because of the difference in electric output before and after the ice fragmentation, the ICE-TENGs are designed to construct a warning system to remind the danger when the ice surface suddenly shatters. Moreover, such ICE-TENGs are capable of lighting "ICE" LEDs and powering an electric watch with footsteps. This illustrates a promising potential in self-powered systems such as danger warning, charge shortage, and energy harvesting.