Triboelectric Circular Motion Sensor with Variable Friction Type and its Service Performance Research

Due to their simple structure, low cost, and self-powered characteristics, triboelectric nanogenerators are widely used in mechanical sensing fields. However, the existing investigations on triboelectric sensors mainly focus on a single friction type or material. In this paper, a triboelectric circular motion sensor with variable friction types (TCMS-VFT) is proposed. TCMS-VFT consists of a stator and a slider. Sliding, rolling, and sweeping friction between the slider and the stator can be achieved by replacing different types of sliders. The output characteristics, the durability of TCMS-VFT with different materials, structures, and friction types are systematically investigated. The experiment results show that TCMS-VFT with sliding friction has excellent output capability and stability. The service life of TCMS-VFT with a solid-block triboelectric layer can reach 200 000 revolutions (236.2 km) and 140 000 revolutions (165.34 km) under sliding friction and rolling friction, respectively. Compared to conventional films, this represents significant increase in durability. In particular, the service life of TCMS-VFT with sliding friction is increased by more than 30 times. The sensing experiments indicate that the accuracy of TCMS-VFT with sliding friction is better than that of the rolling friction and the sweeping friction, with an absolute error rate of less than 0.41% for velocity, an accuracy of ±0.42° for angular displacement. This paper can provide a guiding ideology and experimental basis for the structure design and practical application of triboelectric sensors.