Optic tweezers

conceptual description of laser beams that are used to trap and manipulate small particles (e.g., cells or molecules). These beams of light act rather like small tweezers that can exert forces due to the differences in the index of refraction between the medium and the particle suspended in that medium. A laser beam, focused through a lens of high numeric aperture, has the ability to lock into position microscopic particles, a mechanism known as a laser trap. SYN: laser tweezers.