Electrorheological Fluids
“Electrorheological (ER) fluids are suspensions of extremely fine non-conducting particles (up to 50 micrometres diameter) in an electrically insulating fluid. The apparent viscosity of these fluids changes reversibly by an order of up to 100,000 in response to an electric field. For example, a typical ER fluid can go from the consistency of a liquid to that of a gel, and back, with response times on the order of milliseconds. The effect is sometimes called the Winslow effect, after its discoverer the American inventor Willis Winslow, who obtained a US patent on the effect in 1947 and wrote an article published in 1949” (Wikipedia, Electro-Rheological Suspensions, 5/17/2011) (Winslow, US Patent 2,417,850; 3/25/1947)
Recent Journal Articles
Development and flow evaluation of electro-rheological nano-suspensions
(855-862) Colloid and Polymer Science 289 #7 (2011)
Tanaka et al of the Kyoto Institute of Technology and Tohoku Universitydevelopeda candidate for electro-rheological (ER) nano-suspensions based on anatase titanium dioxide with a particle diameter around 300 nm. The micro-gap flow behavior and microstructure were evaluated for a suspension with a particle volume fraction of 8.8 vol.%. The ER effect was investigated for the nano-suspension. The effect of shearing time on the ER responses was also investigated. The ER effect was discussed in comparison to the effect previously reported for the nano-suspension based on rutile