Frequency adjustable MEMS vibration energy harvester

[摘要] Ambient mechanical vibrations offer an attractive solution for powering the wireless sensor nodes of the emerging "Internet-of-Things". However, the wide-ranging variability of the ambient vibration frequencies pose a significant challenge to the efficient transduction of vibration into usable electrical energy. This work reports the development of a MEMS electromagnetic vibration energy harvester where the resonance frequency of the oscillator can be adjusted or tuned to adapt to the ambient vibrational frequency. Micro-fabricated silicon spring and double layer planar micro-coils along with sintered NdFeB micro-magnets are used to construct the electromagnetic transduction mechanism. Furthermore, another NdFeB magnet is adjustably assembled to induce variable magnetic interaction with the transducing magnet, leading to significant change in the spring stiffness and resonance frequency. Finite element analysis and numerical simulations exhibit substantial frequency tuning range (25% of natural resonance frequency) by appropriate adjustment of the repulsive magnetic interaction between the tuning and transducing magnet pair. This demonstrated method of frequency adjustment or tuning have potential applications in other MEMS vibration energy harvesters and micromechanical oscillators.

[发布机构] Micro-Nano Systems Centre, Tyndall National Institute, Cork, Ireland^1;Photonics Centre, Tyndall National Institute, Cork, Ireland^2;School of Mathematical Sciences, University College Cork, Cork, Ireland^3;A.S. Paintal Chr. Prof. in Engineering, Indian National Science Academy, India^4

[效力级别] 力学 [学科分类] 力学，机械学

[关键词] Electromagnetic transduction;Electromagnetic vibrations;Frequency tuning range;Magnetic interactions;Micromechanical oscillators;Natural resonance frequencies;Resonance frequencies;Vibration energy harvesters