A low-frequency piezoelectric-electromagnetic-triboelectric hybrid broadband vibration energy harvester

In practical applications, vibration-based energy harvesters are usually restricted by their output performance and operating bandwidth. Therefore, improving the performance and increasing the operating bandwidth of vibration energy harvester become to two significant and urgent research focuses in past years. In this paper, a low-frequency piezoelectric-electromagnetic-triboelectric hybrid broadband vibration energy harvester is presented and investigated. It consists of flexible PET picking-up vibration structures which designed to achieve broadband behavior at low acceleration. In the meanwhile, integrate piezoelectric, triboelectric and electromagnetic mechanisms successfully enhanced the electric output of the hybrid energy harvester. As a result, the novel hybrid harvester can scavenge vibration energy at a wide vibration frequency. Under 0.5g acceleration at 20 Hz, the novel hybrid harvester obtained maximum output power 41.0 μW at a load resistance of 800.1 kΩ for one PEH unit, 66.5 μW at a load resistance of 343.1 Ω for one EMEH unit, and 4.6 μW at a load resistance of 1.4 MΩ for one TEH unit, and the piezoelectric, electromagnetic and triboelectric EH units can reach 3.5 Hz, 10.0 Hz, and 18.1 Hz operating bandwidth under 0.5 g acceleration, respectively.