Concurrent Passive Broadband Vibration Suppression and Energy Harvesting Using a Dual-Purpose Magnetoelastic Metamaterial Structure: Experimental Validation and Modeling

Abstract

A dual-purpose metamaterial structure that can concurrently suppress vibrations and scavenge energy is presented. The metamaterial assembly presented in this work uses a permanent magnet-coil system in addition to an elastic cantilever beam to perform its dual functions. A prototype is manufactured and a COMSOL model is developed. Two bandgaps are observed at 205–257 Hz and 587–639 Hz. COMSOL simulations show excellent agreement with measured data. Within these bandgaps the structure blocks vibrations from traveling through and, simultaneously, converts vibrations into electric power. The first bandgap has a vibration attenuation level larger than the attenuation level observed in the second bandgap. Mode shapes reveal that the local resonators experience larger deformations in the first bandgap than in the second bandgap and the vibrational energy is mostly contained within the first bandgap where the resonant frequency occurs, i.e., 224 Hz. The ability of the metamaterial assembly to scavenge these vibrations while simultaneously suppressing them is demonstrated. At an optimum load resistance of 15 Ω, within the first bandgap, approximately 2.5 μW was generated, while 0.6 nW was measured within the second bandgap. At optimum load resistance, measurements show maximum electric power reaching 5.2 μW within the first bandgap.