ZnO Nanowire-Based Piezoelectric Nanogenerator Device Performance Tests

Abstract

Over the past two decades, the quick development of wireless sensor networks has required the sensor nodes being self-powered. Pushed by this goal, in this work, we demonstrated a ZnO nanowire-array-based piezoelectric nanogenerator (NG) prototype, which can convert mechanical energy into electricity. High-quality single crystalline ZnO nanowires, having an aspect ratio of about 15, grown on gold-coated silicon substrate, were obtained by using a low-cost and low-temperature hydrothermal method. The NG-device fabrication process has been presented in detail, and the NG’s performance has been tested in both compression and vibration modes. Peak power of 1.71 µW was observed across an optimal load resistance of 5 MΩ for the ZnO nanowires-based NG, with an effective area of 0.7 cm2, which was excited in compression mode, at 9 Hz, corresponding to ~38.47 mW/cm3 volume-normalized power output. The measured voltage between the top and bottom electrodes was 5.6 V. In vibration mode, at 500 Hz, the same device showed a potential of 1.4 V peak-to-peak value and an instantaneous power of 0.04 μW, corresponding to an output power density of ~0.9 mW/cm3.