A gearwheel rotation operated by a light-driven molecular crystal actuator.
The 3.2-mm-diameter gear was rotated by the crystal, which showed reversible
bending upon alternate irradiation with UV and visible light.
micromuscles based on polymers, the new microrobotic arm
is wireless and responds quickly, even in water and at low
“The light-driven actuators can be remote-controlled even in
water, and the size can be reduced to micro- or nanometers,” Irie
said. “The robust actuators can find versatile applications in bio-
logical and medical fields as light-driven mechanical tools.”
The scientists also observed that if one end of the crystal rod is
anchored, alternating irradiation with UV and visible light could
be used to induce the loose end to cause a small gear to turn. It
could also be used to work as a freight elevator: If attached to a
ledge, the rod can lift a weight more than 900 times as heavy as
the crystal itself. This makes it equivalent to piezoelectric crystals
and stronger than polymer muscles.
Next up, Irie said his team will work toward how to efficiently
prepare the rodlike crystals with controlled size.
Microplasma arrays promise
to revolutionize lighting
ARLINGTON, Va. – A new plasma-based lighting system comprising microcavity arrays produces inexpensive, wafer-thin,
flexible sheets of light – and its creators say it will revolutionize illumination.
Just as in a fluorescent light, a microcavity array is energized
by an applied voltage. The new technique, developed by Dr.
Gary Eden and Dr. Sung-Jin Park of the University of Illinois
at Urbana-Champaign, involves confining plasma in parallel
rows of microcavities within thin-sheet materials and introducing electricity.
The discovery began to take shape in 1996, when two graduate
students approached Eden with a block of silicon and asked if
they could drill a small hole in it to try to produce a plasma inside the hole. They did this with a hole about 400 μm in diameter,
which Eden said was a crude forerunner of the current microcavity array (MCA) lighting system.