Rising requirements for a new constructions, devices and machines force engineers to monitor them all day long. An attractive solution seems to be applications of wireless sensors. However, there is a barrier limiting their application, which is the need to supply them with an electrical power over extended period of time without using additional wiring or batteries. The potential solution of this problem seems to be an energy harvesting. Most methods of obtaining the energy from the external sources e.g. vibrations, is to use piezoelectric materials. However, the amount of energy generated by piezoelectric materials is smaller than most electronic devices need. Therefore a new method for generating a pulse of energy and conditioning for other loads devices must be developed. This paper proposes a new energy harvesting device based on magnetostrictive material. In the course of the experiments with using Terfenol-D rods as actuators and sensors it has been observed interesting phenomenon. Mechanical impact (e.g.energy between 1J and 10J in infinite time) to magnetic core based on Terfenol-D rod (diameter 5mm, length 10 mm), NdFeB permanent magnets and coil allowed get electric power signal enough to supply device of 100 Ohm load on their active state (typical low power controller). In comparison to the same magnetic circuit built with other typical ferromagnetic materials e.g. Armco iron, showed effect 10 times lower or none. Tests and experiments showed the important role of coupling Terfenol-D and NdFeB permanent magnets, their configuration and variable coil parameters determined this effect. In regard to the results the authors proposed the construction of a new impulse harvesting method based on Terfenol-D material for low impedance load.

Date Published: 30 March 2010
PDF: 12 pages
Proc. SPIE 7644, Behavior and Mechanics of Multifunctional Materials and Composites 2010, 76440U (30 March 2010); doi: 10.1117/12.847974

Published in SPIE Proceedings Vol. 7644:
Behavior and Mechanics of Multifunctional Materials and Composites 2010
Zoubeida Ounaies; Jiangyu Li, Editor(s)