Rational design of a miniaturized mechanical frequency regulator for the sustained triboelectric generation

Mechanical design offers an effective way to improve triboelectric performance. However, mechanical components can increase the system volume for an installation. In this work, the miniaturized mechanical frequency regulator-based triboelectric nanogenerator (MMFR-TENG) was investigated to utilize irregular mechanical energies and enhance the applicability of mechanically designed TENGs. Based on the wind-up mechanism and the noncontact freestanding mode, the mechanical components and structure were designed and integrated. Based on the rotational energy analysis and root mean square (RMS) outputs, the effects of mechanical component parameters, such as the moment of inertia of rotators, mainspring stiffness, and switch structure, on triboelectric performance and characteristics were assessed, and optimized mechanical conditions were determined. In addition, two different operation modes of the MMFR-TENG, frequency regulation and continuous operation modes, were demonstrated. Our MMFR-TENG can provide an RMS power of 17.9 μW under irregular mechanical energy inflow in the frequency regulation mode. A handheld MMFR-TENG and its capability to charge capacitors were demonstrated. Our MMFR-TENG provides an effective technique to improve the applicability of mechanically designed TENGs in real life.