Continuous rotation of eccentric triboelectric nanosensor under low frequency periodic vibration

Abnormal vibration and external impact are critical issues to mechanical structures as they can sometimes cause fatigue or even failure. An Eccentric Triboelectric Nanosensor (Ec-TENS) model has been proposed in our previous study to monitor these abnormal events, but specifically for an instant external impact. However, in many real life scenarios, low frequency vibration is more prevalent. Therefore, in this paper, the properties of Ec-TENS under a continuous low frequency vibration mode are investigated to enrich the theoretical principle of the previous sensor in this new mode, and the output performance at larger horizontal velocity range is illustrated by experiments. Firstly, the mathematical model of Ec-TENS is rebuilt under a continuous low frequency vibration mode, which demonstrates the horizontal velocity threshold for continuous rotation of Ec-TENS. According to the mathematical model, a series of prototypes has been fabricated and tested. The experimental results verify that the relationship between the rotor rotation angle and the external horizontal velocity is affected by the rotor radius and the rotor edge counterweight. In addition, it can be used for energy harvesting under low frequency periodic vibration according to the repeatability test.