A hybrid piezoelectric-triboelectric generator with inertial amplification for vibration energy harvesting

Low-frequency vibrations are widely present in engineering structures and environments, yet traditional energy harvesters struggle to efficiently harvest such energy, limiting their practical applications. This study proposes a novel hybrid piezoelectric-triboelectric energy harvester (P-TENG) that integrates an inertial amplification mechanism with dual-function Euler-buckled beams to efficiently harvest low-frequency vibration energy. The inertial amplification mechanism transforms vertical vibrations into coupled horizontal-vertical motions, enabling the system to achieve multi-directional energy harvesting from simple uniaxial excitation. Simultaneously, the Euler-buckled beams dual-function as elastic supports and piezoelectric converters, leveraging buckling-induced strain for energy harvesting. A dynamic model of the P-TENG is established and numerically simulated to analyze its dynamic response, nonlinear behavior, and voltage output performance. The results demonstrate distinct stiffness hardening and hysteresis phenomena observed through bidirectional frequency sweeps. Furthermore, the system performance is highly sensitive to geometric configurations, particularly the assembly angle, which significantly affects inertial amplification effects. Experimental results demonstrate that the harvester can achieve peak output voltages of 3.76 V (PEH), 8.12 V (TENG1), and 7.38 V (TENG2) at 12 Hz under 9.8 m/s² excitation, capable of directly powering 31 commercial LEDs connected in series and enabling self-powered operation of a low-power SHT30 temperature-and-humidity wireless sensor node. This design provides a reference for developing advanced hybrid energy harvesters with improved multi-transduction mechanisms integration capabilities.