Preparation And Testing Of New Micron Vibration Piezoelectric Energy Harvester

With the increasingly tense energy source, much attention has been paid to energy collection technology, energy collector has been widely studied as a result of the development of the micro sensor. Its application fields are diversified, including monitoring sensor, medical embedded sensors, power supply for automotive, power supply for unmanned aerial vehicle,power supply for home security system, and so on. For daily life and production under indoor environment, vibration energy harvesting technology are more potential. Based on a number of scholars,electromagnetic vibration energy harvesting technology, electrostatic vibration energy harvesting technology and piezoelectric vibration energy harvesting technology appeared. After a comparative analysis of those three vibration energy harvesting technology,piezoelectric vibration energy harvesting technology is more suitable for powering a microelectronic device, more easily integrated with MEMS technology, so as to realize batch production.After the analysis of the existing research of piezoelectric vibration energy harvester, the existing research have several deficiencies. The output of piezoelectric vibration energy harvesters is closely linked to the structure dimensions,and the structure design of the existing research have no guidelines to follow, if s lack of theoretical foundation. The dimension of energy harvester is oversized in order to pursue high output, then not suitable for microelectronic devices. In terms of the production process, many research are based on the traditional mechanical processing, even manual adhesion.In order to improve the output, at the same time, controlled the size of the device is not too large, designed a comb structure piezoelectric vibration energy harvester with multi beam. And then prepared of the entity using MEMS technology,each layer’s material and the order is:Si/Si02/Ti/Pt/PZT/Ti/Pt/Si3N4. In order to explore suitable flexible substrate of the piezoelectric energy harvester based on MEMS fabrication processes, PZT thin films was prepared respectively in 0.05 mm stainless steel, 0.01 mm stainless steel, and TC4 titanium alloy /Ti/Pt, TC4 titanium alloy/Cu, Si/Si02/Ti/Pt substrates. Testing and analysis the results of the experiment. In order to detect the characteristics of the piezoelectric vibration energy harvester to characterize it,and then improvement it,this paper examined the characteristics of piezoelectric materials and the characteristics of energy harvester。The performance of piezoelectric material(PZT film), including XRD analysis of crystal phase, AFM analysis of surface morphology and dielectric properties, piezoelectric properties, ferroelectric properties.The test results show that, the prepared PZT thin films was formed perovskite organisation with(110) orientation, which has better performance than other orientation, and the prepared PZT thin films have compact structure, no significant defects. The dielectric constant variation of the prepared PZT thin films is normal, the maximum value is 2352, the dielectric loss is 0.046; the leakage current is very small, generally less than 4xlO’^A. For ferroelectric properties, the remnant polarization is Pr=37.037 C/cm^, coercive electric field is Ec=27.083KV/cm.Piezoelectric constant d33=28 pC/N.Since the dimension order of magnitude of the prepared energy harvester in this paper is micrometer, and the piezoelectric material is very sensitive to external factors. The influence of vibration, noise, air flow and other factors on the output of the device is very large, which leads to the test result is not convincing enough.The existing testing system only suitable for the measuring of large size piezoelectric vibration energy harvester, this paper build a new test system that can filter out the interference. The maximum ou^ut voltage of beam 4 up to80.78 mV; and the power density is 147.42209 p.W/cm^.