Integrated nanogenerators with multimodal excitation and strain matching for frequency broadening and output enhancement

Abstract

Harvesting mechanical energy from the environment is a viable solution to the distributed power supply needed by the IoT. However, the narrow working frequency, integration difficulties, and large size have prevented current devices from fulfilling their application potential. This paper proposes an integrated multimodal nanogenerator (IMNG) based on a staggered L-shaped structure array. The device structure enables multiple vibration modes to work constructively for a broadened operating frequency range (15–75 Hz). Thanks to the desired matching of device strain distribution with different energy harvesting mechanisms, the optimized and synchronized piezoelectric and triboelectric nanogenerators significantly enhance output performance. The compact and miniaturized configuration (77 mm × 45 mm × 25 mm) allows the device to be deployed in space-constrained environments and harvest low-frequency vibration energy from automobiles. This work provides an effective strategy for frequency expansion, integration, and miniaturization, and promotes the application and development of vibration energy harvesting technology.