基于单极性驻极体薄膜的振动能俘获研究

Vibration energy harvesting with uni-polar electret film

利用电晕充电方法成功制备了单极性交联聚丙烯(IXPP)驻极体膜,并设计、制备了基于该驻极体膜的振动能量采集器.通过表面电位的测量,研究了IXPP驻极体膜的电荷储存稳定性;通过测量振动能量采集器样品的准静态和动态电荷灵敏度,考察了能量采集器的机电耦合性能,研究了能量采集器在{3-3}模式下对环境振动能的俘获.结果表明,用-13 kV的电晕电压与-2.0 kV的栅极电压给单面镀铝电极的IXPP样品充电,在实验室环境下放置15天后获得-680 V稳定的表面电位;利用准静态方法测量器件样品的电荷灵敏度,在1.3 kPa压强下,样品的准静态电荷灵敏度M高达1800 pC/N;对于有效面积为13 cm^2的能量采集器,当振子质量为42.2 g,在共振频率70 Hz处,样品在最佳负载电阻80 M?附近的输出功率为5μW.

Electronic devices are highly demanded commodities and will continue increasing in popularity in the near future,all of which require powers in one way or another. A challenge that arises in remote or inconvenient locations is access to reliable power sources. Energy harvesting technology is critical in the development of self-powered electronic devices.In this paper we present a novel approach to vibration energy harvesting, which is based on uni-polar electret film.Uni-polar electret film is of a flexible polymeric material which can exhibit permanent polarization and induce durable electric filed. In this study, real charge electret films are prepared by using the negative corona charging one-side metalized irradiation cross-linked polypropylene（IXPP） films. Vibration energy harvesters based on such electret films are designed and fabricated. The charge stability in IXPP electret film is investigated by measuring the surface potential of sample. The electromechanical properties of the energy harvester sample are tested by measuring quasi-static and dynamic sensitivities. The energy harvesting from vibrations by using the energy harvester sample, at various vibration frequencies, load resistances, and seismic mass values, is also studied. The results show that as the IXPP film is charged with a corona voltage of-13 kV, grid voltage of-2.0 kV and charging time of 60 s, the stable surface potential of-680 V is obtained after 15-day storage in the laboratory environment. The quasi-static sensitivity of energy harvester sample is 1800 pC/N at a pressure of 1.3 kPa. At an optimum load resistance of 80 MΩ and a resonance frequency of 70 Hz,a maximum output power of 5 μW is obtained for an energy harvester sample with an effective area of 13 cm^2 and a seismic mass value of 42.2 g.