Scientists at the U.S. Department
of Energy's Argonne National Laboratory are developing a way to control
the Casimir force, a quantum mechanical force which attracts objects when they
are only a hundred nanometers apart.
"The Casimir force is so small that most experimentation has dealt simply
with its characteristics," said Derrick Mancini, interim director of Argonne's
Center for Nanoscale Materials. "If we can control this force or make it
repulsive, it can have dramatic effects on the development of nanoelectromechanical
Nanoelectromechanical systems (NEMS) are nano-meter size mechanical devices
that can be used for actuation or sensing at the nano-scale. Many NEMS devices
are currently being developed for unique applications in sensing, telecommunications,
signal processing, data storage and more. In the macro world, the Casimir force
is so small that it can barely be detected, but at the nanoscale it becomes
a quantum effect that scientists cannot currently control.
"As characteristic device dimensions shrink to the nanoscale, the effects
of the attractive Casimir force become more pronounced, making very difficult
to control nano-devices. This is a technological challenge that needs to be
addressed before the full potential of NEMS devices can be demonstrated,"
scientist Daniel Lopez said. "The goal is to not only limit its attractive
properties, but also to make it repulsive. A repulsive force acting at the nano-scale
would allow engineers to design novel NEMS devices capable of frictionless motion
The approach to controlling this force involves nanostructuring the interacting
surfaces to tune the effects of the Casimir force.
Argonne National Laboratory was recently selected by the Defense Advanced Research
Projects Agency (DARPA) to develop mechanisms to control and manipulate the
Casimir force. This program will be developed in close partnership with Indiana
University - Purdue University Indianapolis, National Institute of Standards
& Technology (NIST) and Los Alamos National Laboratory.