Submillimeter-Scale Superlubric Triboelectric Nanogenerator

Triboelectric nanogenerator (TENG) for mechanical energy harvesting has been regarded as one of the most prospective energy technologies for the new era. However, inevitable material wear during triboelectrification results in output reduction and even failure of the TENG. In this work, a submillimeter-scale superlubric TENG (SS-TENG) is reported that enables ultra-low friction coefficient (mu) and stable power generation. By using the micro/nano-processing technology, the interdigital electrodes are embedded into the dielectric layer as a flat surface, on which the highly-hydrogenated diamond-like carbon (PLC) is deposited as the triboelectric layer to effectively reduce the friction coefficient. The frictional properties are systematically investigated at different parameters, in which a submillimeter-scale (130 mu m) superlubricity state (mu = 0.0084) is achieved at 4 N, 2 Hz and nitrogen atmosphere. Meanwhile, the SS-TENG has a maximum power density of 3 mW m(-2), which can remain stable at the superlubric condition. This work has first realized the freestanding-mode superlubric TENG in submillimeter scale and provided a viable strategy for the development of long-lifetime TENG, which may have great applications in frictional energy recovery from mechanical components, human joint motion, and the natural environment.