Electromagnetic energy harvesting from vibrations induced by Kármán vortex street

► A device for harnessing energy from Kármán vortex street is developed. ► The energy harvester can generate a voltage of nearly 20mVpp. ► The excitation pressure has an amplitude of 0.3kPa and a frequency of about 62Hz. ► The miniaturized device can convert hydraulic energy into electricity. A new electromagnetic energy harvester for harnessing energy from vibration induced by Kármán vortex street is proposed. It converts flow energy into electrical energy by fluid flow, vortex shedding from a bluff body and electromagnetic induction. An analytical design method for the energy harvester is developed. A prototype of the energy harvester is fabricated and tested. The prototype has a volume of 37.9cm3. Experimental results show that an output peak-to-peak voltage of nearly 20mV in average is generated when the excitation pressure oscillates with an amplitude of 0.3kPa and a frequency of about 62Hz. By detecting the voltage drop across a matched load, the instantaneous power is determined as 1.77μW under a pressure fluctuation frequency of 62Hz and a pressure amplitude of 0.3kPa in the Kármán vortex street.