Swarming microrobots use spinning flows to turn gears without touching

E pluribus unum—”out of many, one”—is not only a motto for the United States; it’s a good credo for microrobots. A research collaboration between Cornell and the Max Planck Institute for Intelligent Systems has shown how a swarm of microrobots spinning on a water surface can together generate the fluidic torque needed to manipulate passive structures without any physical contact. This collective behavior was demonstrated to operate gears and move objects, with the aim of eventually performing microscale tasks and biomedical procedures.