ISBN 9783843957229

978-3-8439-5722-9, Reihe Elektrotechnik

Frank Eric Boye Anang
Piezoelectric-Energy-Harvesting Devices Based on Zinc Oxide Nanowire Arrays

258 Seiten, Dissertation Technische Universität Braunschweig (2026), Softcover, A5

Zusammenfassung / Abstract

In this study, zinc oxide (ZnO) nanowires (NWs) are utilized to generate piezoelectric potentials via impulse-type compressive and vibrational forces. Initially, ZnO NW arrays were selectively grown on patterned surfaces of a silicon (Si) substrate using a devised MEMS-compatible chemical bath deposition (CBD) method. The fabricated device with NW array length of (1.83 ± 0.14) μm and diameter of (0.20 ± 0.07) μm, had a layer of SU-8 polymer on the NWs and sandwiched between a top and bottom Cr/Au electrode. A maximum peak output voltage of ≈ 21.6 mV was measured using an I-V parameter analyzer when a mass of 91.5 g (≈ 0.9 N) was repeatedly and manually placed on it. A peak power density per active volume of 0.22 µW/cm3 and an areal power density of ≈ 0.043 nW/cm2 were realized, independent of the size of the NW array. To enhance the piezoelectric output, thermo-convective solution growth, (TSG) method was introduced. At a process temperature above ≈ 90 °C, ZnO NWs reached a length of ≈ 26.8 µm within 24 h, corresponding to a growth rate of 1.1 µm/h, nearly double the rate of 0.6 µm/h observed in CBD growth. As PENG device was fabricated by embedding the NWs in an S1818 polymer matrix over a 15 mm × 15 mm area. Under repeated impulse-type compressive forces of 0.9 N, a maximum peak output voltage of ≈ 95.9 mV was recorded, and a power density of ≈ 0.37 µW/cm3 and an areal power density of ≈ 1.06 nW/cm2, with its voltage higher by a factor of 4–5 compared to ≈ 21.6 mV that was previously obtained.