Stable optical lift proved
ROCHESTER, N.Y. – The existence of stable optical lift,
or the use of a beam of light to move and manipulate particles in the micrometer
scale, has finally been proved. Applications include astrophysics, biotechnology
and microelectronics. Someday it could be used to enable long-distance space travel
or to power micromachines.
“Airplanes and automobile spoilers use the concept of aerodynamic
lift to achieve movement,” said Grover A. Swartzlander, joint associate professor
in the department of physics and the Chester F. Carlson Center for Imaging Science
at Rochester Institute of Technology. “Our computer model predicts and our
experiments prove that sustained optical lift is possible and can be used to make
particles move perpendicular to the direction of the light flow. Combined with the
previously known ‘levitation force’ of light, the specially shaped particles
can be made to ‘fly.’ ”
Grover A. Swartzlander, left, led
a Rochester Institute of Technology (RIT) research team that has proved the existence
of stable optical lift. Also pictured are Timothy Peterson, second left, a computer
science master’s student; Alan Raisanen, associate director of the Semiconductor
and Microsystems Fabrication Laboratory; and Alexandra Artusio-Glimpse, right, a
doctoral student in imaging science. Courtesy of William Dube, RIT.
Optical tweezers manipulate particles using a focused light beam,
but optical lift occurs in uniform illumination, which means that particles could
be lifted and moved simultaneously in a single uniform beam of light.
To test the process, Swartzlander and his colleagues developed
computer simulations, then devised an experiment using milliwatt-scale laser light
and microscopic semicylindrical rods. The rods, when illuminated by the laser, exhibited
a levitation force in the direction of the beam and a lift force that was perpendicular
to the beam. They also rotated into a stable orientation and subsequently underwent
The work was published online in December 2010 by Nature Photonics.
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