Self-sustained and self-wakeup wireless vibration sensors by electromagnetic-piezoelectric-triboelectric hybrid energy harvesting

Self-sustained wireless sensing nodes (WSN) with energy harvesting, low power consumption, and intelligent sensing are the key devices in artificial intelligence of things (AIoT) area. This paper designs a tri-hybrid generator with electromagnetic-piezoelectric-triboelectric units integrated into one vibration energy harvesting structure. The tri-hybrid generator has three functions with electromagnetic unit for power supply with 13.1 mW, two piezoelectric units as the accelerometer for amplitude and frequency sensing with broadband decoupling function, triboelectric unit for triggering the self-wakeup WSN. The tri-hybrid generator structure is simulated and optimized by theory and finite element modeling, and the performance is tested in a vibration platform. To achieve self-sustained WSN, this study designs the power management circuit with maximum power point tracking and undervoltage lock function, combining periodic wake-up with overload self-wakeup to decrease 94.2% WSN power consumption. Self-sustained WSN is realized in the laboratory and verified on the vehicle engine. Finally, the application of wireless vibration sensing is verified on the vehicle engine. This work has a wide range of applications in vibration scenarios and hopefully promotes the development of AIoT.