Electric-Field Assisted Hydrothermal Growth of ZnO Nanorods on Flexible Substrate and their Strain Sensing Applications

Abstract

This paper presents an electric-field assisted hydrothermal seedless synthesis of ZnO nanorods (NRs) on flexible polyimide (PI) substrate and their strain sensing applications. A three-electrode structure including top cathode and anode on PI substrate with a Copper layer on the back of PI (served as bottom gate) was fabricated with photolithography, sputtering and lift-off techniques. Hydrothermal growth of ZnO NRs on and between top cathode and anode (comb-like electrode-pair) was realized in Zn (NO3)2 and HMTA solution whilst an alternating current (AC) electric-field was applied onto the electrodes. The strain sensing properties of the fabricated ZnO NRs device were tested by measuring I-V characteristics of the device under different strains. From strain-free to 0.48% strain, the decrease ratio of the current flowing through the device reached 75% at a bias voltage of 1V.