Meta-mass vibration energy harvester

A meta-mass vibration energy harvester MMVEH for harvesting mechanical energy from a vibrating structure VS, defined mathematically by a measure of inertia Mh and a measure of resistance to deformation, the measure of resistance having both an elastic component and a dissipative component, the structure containing vibrations with a given degree of coherence, the MMVEH comprising a rigid housing element of mass connected to at least one local region of the VS, the housing element plus the structure comprising a base system having a resonance equal to ω0, the housing element encapsulating $N$ oscillators, the oscillators being of substantially equal mass that sum to ms and having resonances that are substantially uniformly distributed across a band of width Ω centered at ωc,

• each oscillator causing a time varying internal force to act on the housing element in response to mechanical energy transferred from the VS, the sum of the internal forces determining a net internal force NIF that quantifies the internal transfer of energy between the housing element and the encapsulated oscillators,
• the NIF having a history that is determined as a convolution of a history of an external force that represents the VS as an external mechanical energy source and a time series that has the form of a sequence of pulses,
• each pulse having a width approximately equal to Ω−1 and each separated from its neighbors by an interval approximately equal to NΩ−1, so that the pulses appear well separated when measured in units of Ω−1 for N substantially larger than 1,
• the first of such pulses causing a transfer of some portion of mechanical energy entering the MMMEEC via the housing element during the action time of said first pulse, from said housing element to the encapsulated oscillators, while the time interval between the first and a second pulse assures the energy arriving in the encapsulated oscillators remains trapped therein,
• said portion of energy entering the housing element being transferred to the encapsulated oscillators being determined by the value of a mass ratio ms/(αM+Mh), α being a determinable geometric parameter that depends on the location of the MMVEH, such that for a determinable value said mass ratio substantially all of the energy entering the housing element is transferred to the encapsulated oscillators, wherein the energy remains trapped,
• the MMVEH therefore acting as a “one-way mechanical energy valve” such that energy transfers into but not out-from the MMVEH via the housing element, and the MMVEH acting as a “mechanical battery” such that the energy arriving in the encapsulated oscillators accumulates while awaiting conversion to electricity,
• the value of ms/(αM+Mh) that assures substantially all of the energy arriving in the housing element being transferred to the encapsulated oscillators, which depends on α, Ω/ωc, ω0/ωc and N, being determined by numerical simulations,
• each oscillator being combined with a converter element for converting mechanical to electrical energy, such that the converter elements await the accumulation of mechanical energy arriving in each of the oscillator/converter elements before converting the mechanical energy to an electrical current, and electrical circuitry for collecting and combining each of the electrical currents and outputting the sum of the currents via the housing element.