Researchers at MIT have developed a flexible material inspired
by animal hair that moves in response to a magnetic field.
The surface consists of a thin, flexible polymer skin and a ferromagnetic
hair-like micropillar array. The orientation of these micropillars
can be controlled by an external magnetic field.
The micropillars tilt in the direction of the magnetic field and as a
result the pillars can control the direction in which fluids spreads
through the material. When the magnetic field switches direction
the fluid instantaneously changes direction following the orientation
of the field. Even on a vertically inclined surface fluid can be
tuned to climb against gravity. The material can also influence a fluids
drag. Under a more tilted magnetic field a droplets drag across the
material is reduced. In addition to manipulating the flow of fluids
the materials tilting pillars can also influence optical patterns
similar to the way window blinds filter sunlight.
The researchers say this work provides exciting opportunities for
real-time fluid and light manipulation. The surface can serve as
an important platform for applications such as smart windows,
versatile artificial skin, cell manipulation, dynamic optical devices
and fluid control.