Researchers have created an optical tractor beam capable of pulling a macroscopic object. A special graphene-silica composite was designed for the laser-pulling. When irradiated by the laser beam, the composite creates a reversed temperature difference which pushes it towards the laser source. This movement was visible to the naked eye. The study shows that manipulation of a macroscopic object is possible by carefully controlling the interactions between the object, light, and medium. The medium used in the experiment is similar to that of Martian atmosphere and thus, has potential for application in the exploration of Mars.
Reference: Lei Wang, Shige Wang, Qiuling Zhao, Xia Wang. Macroscopic laser pulling based on the Knudsen force in rarefied gas. Optics Express, 2023; 31 (2): 2665 DOI: 10.1364/OE.480019