A high-stability triboelectric nanogenerator with mechanical transmission module and efficient power management system

The triboelectric nanogenerator (TENG) has been demonstrated to be a promising technology for harvesting mechanical energy and powering electronic devices. However, it is difficult to make TENG output stable because of the irregular movement of actual mechanical sources in the environment, and the inefficient energy utilization limits its application. In this study, we propose a contact-separation TENG (CS-TENG) integrated with a mechanical transmission module and its optimal power management system. Firstly, a gear and cylindrical cam mechanism is designed in the mechanical transmission module, which respectively increases the working frequency of CS-TENG and makes the output stable. Secondly, a control module is developed in the PMS to accurately control a switch for extracting maximum output energy, and a series of simulation and experiments have been done to further study the effect of control parameters on the energy extraction process. In the control module, a differential circuit is used to detect the peak of the output voltage. It is found that an optimum differential resistance can increase the detection accuracy and reduce external interference. A time-delay circuit is used to accurately control the switch-on time. As the switch-on time increases, the energy extraction efficiency first increases and then decreases. Finally, the energy extraction efficiency of PMS reaches to 37.8% with the optimal control parameters. We not only solve the problem of the irregular output of TENG, but also provide a guidance for optimizing the design of self-powered system.