Smallest on-chip motors that fit inside a strand of hair developed

Researchers at the University of Gothenburg have developed the smallest on-chip motor to date, featuring gears so tiny they can fit inside a human hair strand. These microscale gears, approximately 0.016 millimeters in diameter, overcome a longstanding size barrier in micromachine technology by using light-powered motion rather than traditional mechanical drive trains. The innovation relies on silicon gears embedded with optical metamaterials that react to laser light, enabling precise, contactless control of gear speed and rotation direction through adjustments in laser intensity and polarization. This approach eliminates the need for bulky mechanical couplings, allowing for highly scalable and integrated micro-gear systems on chips. The light-driven micromotors have potential applications in fields such as medicine and scientific research, where they could be used to manipulate microscopic particles, control light, or operate as pumps and valves within the human body. For instance, these tiny machines—comparable in size to human cells—could regulate fluid flows or perform precise mechanical functions in lab-on-a-chip