Electromagnetic ferrofluid-based energy harvester

This Letter investigates the use of ferrofluids for vibratory energy harvesting. In particular, an electromagnetic micro-power generator which utilizes the sloshing of a ferrofluid column in a seismically-excited tank is proposed to transform mechanical motions directly into electricity. Unlike traditional electromagnetic generators that implement a solid magnet, ferrofluids can easily conform to different shapes and respond to very small acceleration levels offering an untapped opportunity to design scalable energy harvesters. The feasibility of the proposed concept is demonstrated and its efficacy is discussed through several experimental studies.

► A ferrofluid-based electromagnetic energy harvester is proposed and tested. Conformability of fluids offers unique capabilities to design scalable harvesters.
► Power is sensitive to changes in the fluid surface area and external magnetization.
► Device generates 1 microwatt of output power at a base acceleration of 3 m/s2.