Investigation of resonant and energy harvesting characteristics of piezoelectric fiber composite bimorphs

Abstract This study investigates the resonant and energy harvesting characteristics of a piezoelectric fiber composite bimorph by using theoretical and experimental techniques, including the full-field optical technique, for the purpose of getting a new perspective on the mechanical and electrical energy transformation ability of piezoelectric composites. A laser Doppler vibrometer, impedance analysis, fotonic sensor, and polyvinylidene fluoride sensor are used in the experiments. Furthermore, an optical full-field technique is also used to measure the resonant frequencies and mode shapes of in-plane and out-of-plane vibrations. Finally, the electrical voltage of the piezoelectric fiber composite bimorph with shaker excitation is measured and used for a light-emitting diode. The shaker input voltage, output voltage of the piezoelectric structure, and light intensity are all measured to find out the power generation capacity of piezoelectric composite. The relationship between the energy harvesting ability and excitation methods, the input voltage value, and frequency are obtained through analyses. From the experiment results, it is indicated that the most efficient modes are affected by the excitation method and the location of an excitation point of the shaker. This study helps in understanding the resonant characteristics as well as the energy harvesting capability of piezoelectric composite.