Energy harvesting from mechanical vibrations using multiple magnetostrictive/piezoelectric composite transducers

This paper describes an energy harvester employing multiple Terfenol-D/Pb(Mg1/3Nb2/3)O-3-PbTiO3/Terfenol-D laminate magnetoelectric transducers to convert ambient mechanical vibration into electrical energy. The harvester uses four magnets arranged on the free end of a cantilever beam. The multiple transducers are placed in the air gap between the magnets. The optimal initial positions of the transducers at the static equilibrium are analyzed. And the output characteristics of the harvester employing various numbers of transducers are experimentally studied. Experimental results indicate that the harvester employing multiple transducers can provide higher power and power density. The harvester employing four transducers produces a maximum output power of 7.13 mW, which is 3.95 times higher than that of the harvester employing a single transducer, and the harvester employing two transducers produces a maximum output power of 4.07 mW, which is 1.83 times higher than that of the harvester employing a single transducer. (C) 2011 Elsevier B.V. All rights reserved.