advantage is the speed of response. There are few other effects able to control such large amounts of mechanical or hydraulic power so rapidly. Unfortunately, the increase in apparent viscosity experienced by most Electrorheological fluids used in shear or flow modes is relatively limited. The ER fluid changes from a Newtonian liquid to a partially crystalline "semi-hard slush". However, an almost complete liquid to solid phase change can be obtained when the electrorheological fluid additionally experiences compressive stress. This effect has been used to provide electrorheological Braille displays and very effective clutches. See also Continuum mechanics Debye–Falkenhagen effect Electroactive polymers Electroadhesion Electroviscous effects Ferrofluid Fluid mechanics Magnetorheological fluid Electrowetting Smart fluid References Smart materials