Ferrofluid-based Stretchable Magnetic Core Inductors

[摘要] Magnetic materials are commonly used in inductor and transformer cores to increase inductance density. The emerging field of stretchable electronics poses a new challenge since typical magnetic cores are bulky, rigid and often brittle. This paper presents, for the first time, stretchable inductors incorporating ferrofluid as a liquid magnetic core. Ferrofluids, suspensions of nanoscale magnetic particles in a carrier liquid, provide enhanced magnetic permeability without changing the mechanical properties of the surrounding elastomer. The inductor tested in this work consisted of a liquid metal solenoid wrapped around a ferrofluid core in separate channels. The low frequency inductance was found to increase from 255 nH before fill to 390 nH after fill with ferrofluid, an increase of 52%. The inductor was also shown to survive uniaxial strains of up to 100%.

[发布机构] Sensors and Electron Devices Dir., US Army Research Laboratory, Adelphi; MD, United States^1

[效力级别] 能源学

[关键词] Carrier liquid;Inductance densities;Low-frequency;Nanoscale magnetic particles;Stretchable electronics;Transformer core;Uni-axial strains