Design of mechanical band-pass filters for energy scavenging

In this paper, the design of mechanical band-pass filters to be used in energy scavengers is studied. For such filters an ensemble of cantilever beams is proposed where at the tip of each beam a mass, known as the proof mass, is mounted. It is shown that such an ensemble can be made into a band-pass filter when dimensions of the beams and masses of the proof masses are chosen appropriately. A systematic procedure for designing mechanical band-pass filters is given. It is shown that the maximal frequency band of the band-pass filter is limited and cannot be chosen arbitrarily large: The frequency band is independent of dimensions of the beams and masses of the proof masses. (c) 2005 Elsevier Ltd. All rights reserved.