Microscopic Seesaw That Moves Due to Spooky Quantum Physical Force
Experiment Supports 50-Year Old Theory and May Lead to Practical
Applications
MURRAY HILL, N. J.--(BUSINESS WIRE)--Feb. 9, 2001-- Physicists at
Lucent Technologies' (NYSE: LU - news) Bell
Labs have made a microscopic seesaw that moves in response to a
little-known but strong and pervasive force predicted by
quantum mechanics, the widely-accepted scientific theory that describes the
behavior of atoms and other microscopic
particles.
This experiment, which will be reported in a forthcoming issue of the journal
Science, shows that esoteric physical effects are
important in designing nanoscale machines, which are 1,000 times smaller
than today's micromachines. It also suggests that
such effects might be used to make extremely sensitive sensors in the
future.
The microscopic seesaw is the latest scientific advance from Bell Labs
physicists conducting research in
microelectromechanical systems (MEMS), tiny machines which are
becoming crucial components in devices ranging from
complex optical switches in new data networks to actuators that deploy
airbags.
``We are using our expertise in MEMS to fashion creative experiments that
illustrate what little-known quantum effects come
into play in extremely small devices,'' said Federico Capasso, physical
research vice president at Bell Labs and a member of
the team that produced the seesaw.
According to quantum mechanics, even empty space (vacuum) has a little
energy -- known as zero-point energy --
associated with it. This picture is quite different from the classical
understanding of a vacuum as completely empty space
without any energy. In the quantum description, a vacuum is teeming with
virtual photons that produce constantly oscillating
electromagnetic fields.
In 1948, Dutch physicist Hendrik Casimir predicted that this zero-point
energy would produce an attractive force between
uncharged parallel metallic plates that are very close together. The bizarre
``Casimir force'' was first measured precisely by
physicists in 1997.
Bell Labs physicists recently realized that the Casimir force could be used
to tilt a microscopic MEMS seesaw. They built the
seesaw using a tiny metallized plate that was balanced on a hinge and kept
parallel to the surface of a silicon chip. When a
gold plated sphere suspended on a wire was brought close to the seesaw --
an experimental setup similar to the two parallel
plates -- the seesaw was attracted toward the sphere in agreement with
Casimir's prediction. Their results show that quantum
mechanical effects play a significant role in MEMS systems when the
separation between components is in the nanometer
range (a nanometer is one-billionth of a meter).
An article describing the experiment will be published today on Science
magazine's new Science Express Web site that can
be accessed at: www.sciencemag.org/feature/express/expresstwise.shl.
Other Bell Labs physicists involved in the experiment
were Ho Bun Chan, Vladimir Aksyuk, Rafael Kleiman and David Bishop.
``This experiment has opened up an entirely new sensitivity range for MEMS
devices,'' said Bishop, the director of Bell Labs'
micromechanics research. Bishop's team of MEMS researchers developed
and recently began customer shipments of the
Lucent WaveStar (tm) LambdaRouter, the world's first commercial
all-optical switch capable of switching data at rates up to
terabits per second.
``In addition to making powerful optical switches with MEMS technology, we
use MEMS techniques to do heady scientific
work that pushes the frontiers and may lead to wonderful devices,'' Bishop
said.
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