This paper investigates the potential of designing a vibratory energy harvester which utilizes a ferrofluid sloshing in a seismically excited tank to generate electric power. Mechanical vibrations change the orientational order of the magnetic dipoles in the ferrofluid and create a varying magnetic flux which induces an electromotive force in a coil wound around the tank, thereby generating an electric current according to Faraday's law. Several experiments are performed on a cylindrical container of volume 5x10^-5 m³ carrying a ferrofluid and subjected to different base excitation levels. Initial results illustrate that the proposed device can be excited at one or multiple modal frequencies depending on the container's size, can exhibit tunable characteristics by adjusting the external magnetic field, and currently produces 28 mV of open-circuit voltage using a base excitation of 2.5 m/s² at a frequency of 5.5 Hz.

Date Published: 27 March 2012
PDF: 7 pages
Proc. SPIE 8341, Active and Passive Smart Structures and Integrated Systems 2012, 83410T (27 March 2012); doi: 10.1117/12.917437

Published in SPIE Proceedings Vol. 8341:
Active and Passive Smart Structures and Integrated Systems 2012
Henry A. Sodano, Editor(s)