Optical tweezers have been used by biophysicists since their
invention at Bell Labs in the 1980s, and are typically used to
study cellular components. But they have a few drawbacks, not
least of which are overheating and inefficiency. So engineers at
Harvard have been working on a next-gen model they call
plasmonic nanotweezers to solve those and other issues with
traditional optical tweezers so that tiny particles such as
viruses can be isolated, observed, and manipulated. Back at Bell
Labs, scientists had shined a laser through a microscope lens to
focus it tightly. They found that light, made of electromagnetic
waves, creates a gradient force at the point of focus that is
capable of attracting a tiny particle and holding it in that
beam of light until random motion or some other force knocks it
out. The basic limitation of this approach is that a lens cannot
focus that beam beyond half the wavelength of light, so if the
particle the researchers hope to trap is smaller than the focal
spot, they might have t