Sep. 27, 2011 Engineers at Harvard have created a device that
may make it easier to isolate and study tiny particles such as
viruses. Their plasmonic nanotweezers, revealed this month in
Nature Communications, use light from a laser to trap nanoscale
particles. The new device creates strong forces more efficiently
than traditional optical tweezers and eliminates a problem that
caused earlier setups to overheat. "We can get beyond the
limitations of conventional optical tweezers, exerting a larger
force on a nanoparticle for the same laser power," says
principal investigator Ken Crozier, Associate Professor of
Electrical Engineering at the Harvard School of Engineering and
Applied Sciences (SEAS). "Until now, overheating has been a
major problem with tweezers based on surface plasmons. What
we've shown is that you can get beyond that limitation by
building a plasmonic nanotweezer with an integrated heat sink."
Optical tweezers have been an essential tool in biophysics for
several decades, often used for studyi