Electrostatic MEMS vibration energy harvester for HVAC applications
[摘要] This paper reports on an electrostatic MEMS vibration energy harvester with gapclosing interdigitated electrodes, designed for and tested on HVAC air ducts. The device is fabricated on SOI wafers using a custom microfabrication process. A dual-level physical stopper system is implemented in order to control the minimum gap between the electrodes and maximize the power output. It utilizes cantilever beams to absorb a portion of the impact energy as the electrodes approach the impact point, and a film of parylene with nanometer thickness deposited on the electrode sidewalls, which defines the absolute minimum gap and provides electrical insulation. The fabricated device was first tested on a vibration shaker to characterize its resonant behavior. The device exhibits spring hardening behavior due to impacts with the stoppers and spring softening behavior with increasing voltage bias. Testing was carried out on HVAC air duct vibrating with an RMS acceleration of 155 mgRMSand a primary frequency of 60 Hz with a PSD of 7.15•10-2g2/Hz. The peak power measured is 12nW (0.6 nW RMS) with a PSD of 6.9•10-11W/Hz at 240 Hz (four times of the primary frequency of 60 Hz), which is the highest output reported for similar vibration conditions and biasing voltages.
[发布日期] [发布机构] Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy; NY, United States^1;Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy; NY, United States^2
[效力级别] 能源学 [学科分类]
[关键词] Hardening behavior;Inter-digitated electrodes;Microfabrication process;Nanometer thickness;Primary frequencies;Softening behavior;Vibration condition;Vibration energy harvesters [时效性]