Laser light that can trap and move microscopic objects is now the subject of a $100,000 study funded by NASA.
The study will look at three methods for corralling and transporting particles, single molecules, viruses, ribonucleic acid and cells to a robotic rover or spacecraft using lasers. The three methods are the optical vortex, also known as optical tweezers, optical solenoid beams and a Bessel beam.
'We want to make sure we thoroughly understand these methods. We have hope that one of these will work for our purposes,' study team member Barry Coyle said. 'Once we select a technique, we will be in position to then formulate a possible system. We're at the starting gate on this.'
The Bessel beam induces electric and magnetic fields in the path of an object enabling it to be pulled backward, against the direction of the beam. But this method has never been demonstrated, it is only a theory.
Optical tweezers, which have been demonstrated, use two counter-propagating laser beams that overlap. A particle can be trapped by the overlapping lasers and by alternating the intensity of the beams the particle can be moved. However, this method requires the presence of an atmosphere because the particle is moved when the air is heated by the beams' alternating intensity.
Optical solenoid beams have a property that enables them to exert an electromagnetic force that pulls the illuminated objects in the opposite direction to that of the light. Because this method relies on electromagnetics it does not require an atmosphere.