低频响应MEMS压电式微型振动发电机

MEMS Piezoelectric Micro-Vibration Generator Under the Low Frequency Response

利用溶胶-凝胶工艺实现均匀致密压电(PZT)膜与Pt/Ti/SiO2/Si/SiO2晶片良好异质集成制造,结合湿法腐蚀、干法刻蚀、磁控溅射、光刻和剥离等MEMS加工工艺制造了一种"单中心质量块-8悬臂梁"结构的压电式微型振动发电机,实现了振动能向电能的转换。测试结果表明:在谐振频率16 Hz、加速度激励3 g、16个压电敏感单元相串联条件下,器件开路输出交流电压峰峰值最大,为166.40 mV;当加载1.20 MΩ负载时,输出功率最大,为0.73 nW,单位体积的输出功率为37.27 nW/cm3,压电敏感单元有效单位面积下的输出功率为0.26 nW/cm2。

The fine heterogeneous integrated fabrication of the uniform and dense piezoelectric（PZT）film on Pt/Ti/SiO2/Si/SiO2 wafer was realized by the sol-gel process.And the piezoelectric micro-vibration generator was fabricated in the structure of ＂one center mass and eight microcantilevers＂ with MEMS machining methods,such as the wet etching,dry etching,magnetron sputtering,lithography and lift-off technology,accomplishing the energy transformation from the vibrational energy to the electrical energy.The experimental results show that the designed device can produce the maximum open circuit output AC peak voltage of 166.4 mV with the acceleration excitation of 3 gat the 1st-order resonant frequency of 16 Hz and 16 piezoelectric sensitive units in series.In addition,the output power can reach the maximum value of 0.73 nW at the suitable resistance load of 1.20 MΩ,and the output power per volume is 37.27 nW/cm3 and per effective area of the PZT cell is 0.26 nW/cm2.