Phys.org March 14, 2019
Optical tweezers are used to study proteins, biological molecular motors, DNA and the inner life of cells – to hold objects as small as a single nanoparticle in one place. However, the high intensities of light required by optical tweezers can damage live biological specimens and restrict the types of objects that can be held. Researchers in the UK have developed optically trapped micro-rotors, which are placed in the liquid surrounding the particle, and used to manipulate its movement using fluid flow. As the micro-rotors are rotated, they create a wave in the liquid that exerts a force on the particle. By controlling the directions of each micro-rotor, they can either move the particle to a specific location or hold it in one spot—allowing particles to be sorted or imaged at high resolution. They have successfully demonstrated the technique…read more. Open Access TECHNICAL ARTICLE
A diagram showing 2 optically trapped rotors and how their motion can be used to control a free-floating cell (grey sphere). Credit: Dave Phillips