A vortex-induced vibration-based self-tunable airfoil-shaped piezoelectric energy harvester for remote sensing applications in water

Abstract

With growing innovations on the Internet of Things capabilities, automated monitoring and remote sensing applications have become important in the modern world. However, with thousands of distributed sensors and wireless communication routers, the power supply continues to be one of the main challenges for an efficient and sustainable operation. This paper deals with designing, developing, and testing a nonlinear airfoil-shaped piezoelectric energy harvester from flow-induced vibration. The harvester converts flow-induced vibration from water into electrical energy that can be conveniently stored and used to power smart remote sensors. A passive self-adjustable base compensates for the changing flow direction that can reduce the conversion efficiency of energy harvesters. Different beam substrate profiles were investigated for misalignment correction with thin airfoil profiles able to orient faster at higher misalignment angles. The airfoil-shaped piezoelectric energy harvester outperformed the conventional rectangular beams with equal volume with an additional inline mode observed for the same frequency range in low-velocity flow. The piezoelectric macro-fiber composite had an average RMS output of 132 mV for transverse oscillations in the absence of flow misalignment. Experimental studies have shown a performance reduction in both time and frequency domains between 50% and 60% for flow misalignment reaching up to 30°.