Piezoelectric Nanofiber/Polymer Composite Membrane for Noise Harvesting and Active Acoustic Wave Detection
Being one of the most common form of energy existing in the ambient environment, acoustic wave has a great potential to be an energy source. However, the effective energy conversion of acoustic wave is a great challenge due to its low energy density and broad bandwidth. In this work, we developed a new piezoelectric nanogenerator (PENG) which is mainly composed of a piece of piezoelectric nanofiber/polymer composite membrane. As an energy harvester, the PENG can effectively scavenge broad low-frequency (from 50 Hz to 400 Hz) acoustic energy from ambient environment, and it can even scavenge very weak acoustic energy with a minimum pressure of only 0.18 Pa. When a drum is used as an excitation source, the maximum open-circuit voltage and short-circuit current density of the PENG reach 1.8 V and 1.67 mA m-2, respectively. In addition, the PENG has a good stability and its output frequency and amplitude are closely related to the driving sound wave, which makes the PENG capable of detecting the acoustic signals in the living environment and has the potential to be applied as a self-powered active acoustic detector.