Factors About and a Proposed Method to Harvest Acoustic Energy

Abstract

Scientists have tested many different ways to generate electrical energy from other forms of energy, including nuclear, potential, kinetic, solar, and thermal energy. However, acoustic energy has not been as rigorously studied. We are constantly surrounded by sound to the point it may even be considered pollution. There are noises almost everywhere: in karaoke rooms, factories, airports, and highways, to name a few sources. These huge amounts of energy (for example, there is 1 megaWatts amount of power when the sound intensity is 60dB) can be used if we are able to find an effective way to convert acoustic energy to electrical energy, not only to reduce “noise pollution”, but also to relieve the energy problem in our world. In this research, we propose and partially test a potential method to harvest acoustic energy. A speaker/microphone can be used to convert pressure into electrical signals. The efficiency and cost of the system will be evaluated. In addition, future work could use resonance to create a vibration in a small piece of metal and induce electricity using a changing magnetic field. Throughout the research, it was found the proposed diode-capacitor rectifier could convert an AC input (representing an acoustic input) to a DC output (usable electrical energy). These results show a way to generate electricity from noise. Moreover, the proposed device could be used to measure or monitor the intensities of sounds using an LED as a power threshold indicator.  Using resonance, which is highly frequency selective, frequency measurements could be obtained from various acoustic sources.