PVDF/ZnO-PDMS-based hybrid piezoelectric–triboelectric nanogenerator for self-powered sensing and harvesting vibration energy on the train bogies
摘要
With the rapid development of high-speed railway, real-time monitoring of operation safety becomes more and more crucial. However, power supply for microsensors in railway monitoring systems is still demanding and challenging. Stable energy to onboard sensing devices is essential to ensure the safe operation of rail transit systems. Herein, a hybrid piezoelectric–triboelectric nanogenerator (HPTG) is proposed to harvest the vibration energy on the bogie, which is also used as the self-powered sensing for continuous structural health monitoring (SHM) of train bogie. HPTG is designed and fabricated with polyvinylidene fluoride (PVDF)/zinc oxide (ZnO) composite and polydimethylsiloxane (PDMS) film. The experiment results demonstrate that incorporating ZnO simultaneously enhances piezoelectric and triboelectric outputs while improving the overall output performance of the device, fully realizing the synergistic effect of piezoelectric effect and triboelectric effect. Under the condition of external load, the maximum power of the hybrid output is 3.256 μW with excellent working stability. Through the integration of rectifier circuit and energy storage module, the microthermohygrometer is successfully driven. In addition, the feasibility of vibration energy harvesting of HPTG in the actual operating environment is further verified on the small-scale wheel rolling test bench, which provides a solution for the power supply problem of microelectronic equipment for train bogie monitoring, and can effectively help to develop the self-powered monitoring system of rail transit.