Cylindrical bearing inspired oil enhanced rolling friction based nanogenerator

Friction and wear are the main factors influencing the output and lifetime of the triboelectric nanogenerators (TENGs). In this work, inspired by the cylinder roller bearing, an oil enhanced rolling friction based TENG (ORF-TENG) with high output and low friction was fabricated by using polyimide (PI) film, hexadecane, and roller of acrylonitrile butadiene styrene plastic (ABS). Compared to the sliding friction based TENG (SF-TENG), the open circuit voltage (V_oc) and short circuit current (I_sc) increased by 32.1 and 8.3 times, respectively, and the friction coefficient decreased by approximately 84.9% with the maximum conversion efficiency increased by more than 263 times. The electric outputs of ORF-TENG could be modulated by the number, diameter and material of the rollers. The enhanced electric output is mainly attributed to the synergistic effect of the oil molecules and the rolling action of ABS rollers. The triboelectric charges could transfer from the rolled ABS cylinder to the oil molecules to further promote the in-situ generation of triboelectric charges, and thereby resulting in the increase of the surface charge density. This work has pioneered an ORF-TENG, which provides a novel solution for the coexistence of high output and ultralow friction of TENG.