Chalmers researchers create microscopic metavehicles powered by light

Researchers from Chalmers University of Technology in Sweden have created microscopic vehicles that are powered by light. Their breakthrough was made after combining layers of an optical metasurface with a microscopic particle. After building the vehicles, they were able to use a light source to control them.

Using the light source, the researchers could move their tiny vehicles in complex and precise ways. Researchers were also able to use their metavehicles to transport other objects. The researchers have shown that unfocused light can be used to maneuver extremely small, microscopic particles in a precise manner.

Microscopic vehicles created in the research are the scale of 10 micrometers wide and one micrometer thick, which is one-thousandth of a millimeter. The minuscule particles are made of the tiny particle itself coated with a metasurface. A metasurface is an extremely thin arrangement of specifically designed and ordered nanoparticles. Those little particles were designed to direct light in specific ways.

Researchers believe the breakthrough could be used to improve components for optical devices, including cameras, microscopes, and displays. The tiny metavehicles created by the researchers were placed in the bottom of a water dish. A loosely focused laser was then used to direct a plane wave of light onto the particles.

The team was able to control the vehicles in various patterns by adjusting the intensity and polarization of light. The metavehicles were stable enough, and scientists could control them precisely enough that they could be used for more complicated navigation. The heat generated by the light has no impact on moving the particles.

Researchers were also able to use the metavehicles to push small particles inside the tank. During the research, the minuscule objects were able to push microscopic polystyrene beads and a yeast particle through the water. They were also able to push a dust particle 15 times the size of the metavehicle itself.