Soft starters are effective devices used to provide overload protection for motors from large mechanical shocks during the start-up period. However, existing soft starters require additional power supplies, sensors, and complex control elements that pose serious challenges to the integration, versatility, and operability of mechanical transmission system. Herein, we propose a newly soft starter based on the triboelectric nanogenerator (TENG) and electrorheological fluid (ERF) to realize a self-powered mechanical transmission system. Both ERF’s rheological characteristic and the baffle structure play a role in the torque of device. Driven by TENG, the soft starter with optimized baffle achieves a 715% growth in transmission torque compared to that of the device without baffle. And a smooth start is obtained with transmission speeds ranging from 0% to 100%. In application demonstration, this triboelectric soft starter (TSS) has the capacity to gain a smooth operation of the high-speed motor. In contrast, the direct start generates an overshoot, leading to a break in the conveyor belt. The TSS designed in this work with the advantages of self-powered, highly integrated, easy to operate, and low cost, provides a prospective strategy for broadening the application of TENG in mechanical transmission systems.

Efficiently converting the random vibration energy widely existed in human activities and natural environments into electricity is significant to the local power supply of sensor nodes in the internet of things. However, the conversion efficiency of energy harvester is relatively low due to the limitation of device’s intrinsic frequency. In this work, a multi-layered, wavy super-structured-triboelectric nanogenerator (SS-TENG) is designed, whose output performances can be greatly promoted by combining the charge excitation mechanism. The steel sheet acts not only as an electrode but also as a supporter for the overall frame of SS-TENG, which effectively improves the space utilization rate and results in a volume charge density up to 129 mC·m⁻³. In addition, the resonant frequency width of the SS-TENG can be widened by changing the parameters of the superstructure. For demonstration, the SS-TENG can sustainably drive two temperature and humidity sensors in parallel by harvesting vibration energy. This work may provide an effective strategy for harvesting vibration energy and broadening frequency response.