Aeroelastic wind energy harvesting by piezoelectric MEMS device with turbulence capturing

Wind tunnel experiments have been conducted to investigate the effect of turbulence on the power output of a MEM Saeroelastic wind energy harvester of approximately 5.5mm × 5.5mm × 10 mm in size.The energy harvester consistedmainly of a cylinder (2mm diameter, 10mmlength) attached to aMEMS platform equippedwith piezoelectric.The turbulence is artificially created via a turbulence generator comprising of a series of rectangular beams placed in thewind tunnel upstream of the energy harvester. By varying the wind speed andwidth of the turbulence generator beams, it is shown that the time-averaged power output of the energy harvester increases significantly as wind speed and turbulence generator size increases. In particular, replacing a 5mm-width turbulence generator with a 20mm-width turbulence generator can increase the power output by 1710% at wind speed of 6m/s. Power output in the magnitude of tens of nanowatts is measured when the device is exposed to turbulentwinds.Results suggest that the turbulence capturing conceptmay be a promising means of harvestingwind energy for miniature Internet-of-Things devices, such as small wireless sensor nodes that are not connected to the power grid.