High-efficiency piezoelectric micro harvester for collecting low-frequency mechanical energy.
A single-layer zinc oxide (ZnO) nanorod array-based micro energy harvester was designed and integrated with a piezoelectric metacapacitor. The device presents outstanding low-frequency (1-10 Hz) mechanical energy harvesting capabilities. When compared with conventional pristine ZnO nanostructured piezoelectric harvesters or generators, both open-circuit potential and short-circuit current are significantly enhanced (up to 3.1 V and 124 nA cm-2) for a single mechanical knock (∼34 kPa). Higher electromechanical conversion efficiency (1.3 pC/Pa) is also observed. The results indicate that the integration of the piezoelectric metacapacitor is a crucial factor for improving the low-frequency energy harvesting performance. A double piezoelectric-driven mechanism is proposed to explain current higher output power, in which the metacapacitor plays the multiple roles of charge pumping, storing and transferring. An as-fabricated prototype device for lighting an LED demonstrates high power transference capability, with over 95% transference efficiency to the external load.
Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, People's Republic of China.
Xin
X
Li
Jinhui
J
Song
Shuanglong
S
Feng
Xiong
X
Xie
Zhenhu
Z
Li
Liang
L
Wang
Yayun
Y
Pu
Ai Kah
AK
Soh
Jun
J
Shen
Wenqiang
W
Lu
Shuangyi
S
Liu