Piezoelectric nanogenerator based on ZnO nanorods

A piezoelectric nano-generator (PZG) based on in-house ZnO nanorods (ZnO NRs) was constructed and utilized. ZnO NRs were synthesized by tube-in-tube chemical vapor deposition (CVD) technique for large production. To produce large harvested rods, the inner side of a horizontal quartz tube was used as growth platform directly without the aid of substrates or catalysts. The production is about 3–5 g each trail, which is considered as a large scale production in nano-field synthesis. The fabricated nano-rods are polycrystalline in structure and it has (57 ± 11)nm and (3.9 ± 0.8)μm in average diameter and length, respectively. Piezoelectric properties of ZnO NRs were studied by building a real piezoelectric nano-generator, which show the proportional relation between exerted mechanical forces and their outcome voltages. It was found that as the stress force increases more current will flow and the maximum voltage has reached 0.7 V. The nano-generator exhibited Schottky-like I–V characteristics and constructively generated harvesting currents. Current jumps by 4.14 μA when the applied force was increased by about 20 N. Correspondingly, the voltage signal exhibited a similar output of ∼0.25 V. This device can be utilized to generate electricity while walking to charge mobile electronic devices such as hand phones for instance.