Power optimization for a unit cell metamaterial energy harvester

Abstract

Modern living involves using a significant amount of energy, much of which may be wasted or not used efficiently. This apparatus and methodology focuses on potentially wasted energy that is being produced by ambient vibration. Bi-modal broad band energy and/or specific frequency harvester/scavengers utilize the physics of local resonance in acousto-elastic metamaterials (AEMM structures). Frequency selectivity of a harvester depends on the mass of a core resonator, soft material that houses the central mass/resonator, and the base material which is used to manufacture the metamaterial. Piezoelectric materials are known to produce electrical current when they are deformed mechanically. Ambient energy is available in the form of vibration and noise, e.g. car vibration, acoustic noise from heavy machineries, vibration from rails, which is lost, if not otherwise harvested. A smart metamaterial can scavenge/harvest ambient low frequency vibration for charging batteries such that the ambient energy may become a renewable source of energy to power low power electronic gadgets on the go. Power output for a unit cell AEMM embodiment is optimized through one or more of multi-frequency/multi-modal harvesting, geometric optimization, and PZT position optimization.