A New Piezoelectric Bimorph Energy Harvester Based on the Vortex-Induced-Vibration Applied in Rotational Machinery

An innovative wind-induced energy harvester utilizing a piezoelectric bimorph with a pulling strip was designed based on Kármán vortex street theory to collect wind energy from a rotating machinery for powering some devices. A mathematical model was initially established for the model force analysis, and the voltage generated by the piezoelectric bimorph were calculated. The stress distribution on the piezoelectric bimorph was also examined to prevent the piezoelectric material from cracking. A series of experiments were conducted according to the results of the numerical analysis. Both the numerical analysis and the experiments demonstrate that: first, rotation speed is the most important factor that affects the power generation capacity of the piezoelectric bimorph, and with a suitable installing angle, an output power of 1 mW can be easily acquired when the rotation speed exceeds 140 r/min; and, second, choosing an appropriate installing angle can increase the power generation capacity more effectively than rectifying the diameter of the cylindrical obstacle.