Microrobots swim and steer with no brain, sensors, or software

Researchers at Leiden University, led by Professor Daniela Kraft and Mengshi Wei, have created microrobots that can swim, steer, and adapt to their environment without relying on brains, sensors, or software. These microrobots, only a few tens of micrometres long—much smaller than a human hair—are constructed as flexible chains of connected segments using high-precision 3D microprinting. When exposed to an electric field, their shape and flexibility generate wave-like motion, enabling them to move at speeds of about 7 micrometres per second and respond to obstacles in a life-like manner. The key innovation lies in the continuous feedback loop between the robots’ shape and movement: their flexible bodies influence how they move, and their movements, in turn, alter their shape. This interaction allows the microrobots to sense environmental changes and adjust automatically without any electronic control systems. They can avoid obstacles, change direction, navigate crowded spaces, and even push objects aside