Light-driven nanorobots can locate, gather and relocate bacteria in fluids

Scientists at Julius-Maximilians-Universität Würzburg have engineered nanorobots smaller than one micrometer that travel through liquid using photon-recoil propulsion. Each robot contains up to four plasmonic nanoantennas that absorb light of a specific color and helicity and re-emit it, creating a tiny thrust. Steering is achieved by aligning the antenna wires with the polarization direction of the incoming light, allowing rapid 90° turns.

In controlled experiments the bots captured bacteria, moved them across the sample, and released them at predetermined sites, even while carrying larger bacterial groups, though at reduced speed. Lead experimental scientist Jin Qin describes the devices as “microscopic cleaning devices,” highlighting their potential for precise manipulation in microbiology and biomedical research. Professor Bert Hecht notes the work demonstrates how light can actively shape the microscopic world.