Smart fluid

Source: Wikipedia, the free encyclopedia.

A smart fluid is a fluid whose properties (e.g. viscosity) can be changed by applying an electric field or a magnetic field.

The most developed smart fluids today are fluids whose viscosity increases when a magnetic field is applied. Small magnetic dipoles are suspended in a non-magnetic fluid, and the applied magnetic field causes these small magnets to line up and form strings that increase the viscosity. These

National Museum of Emerging Science and Innovation in Tokyo as an earthquake shock absorber
.

Some haptic devices whose resistance to touch can be controlled are also based on these MR fluids.

Another major type of smart fluid are

shock absorbers and hydraulic valves
, other, more esoteric, applications such as bulletproof vests have been proposed for these fluids.

Other smart fluids change their

lenses
: a drop of this fluid, captured in a small cylinder and surrounded by oil, serves as a lens whose shape can be changed by applying an electric field.

Background

The properties of smart fluids have been known for around sixty years, but were subject to only sporadic investigations up until the 1990s, when they were suddenly the subject of renewed interest, notably culminating with the use of an MR fluid on the suspension of the 2002 model of the Cadillac Seville STS automobile and more recently, on the suspension of the second-generation Audi TT. Other applications include brakes and seismic dampers, which are used in buildings in seismically-active zones to damp the oscillations occurring in an earthquake. Since then it appears that interest has waned a little, possibly due to the existence of various limitations of smart fluids which have yet to be overcome.[citation needed]

See also

References