At Leiden University , Professor Daniela Kraft and researcher Mengshi Wei have built microscopic robots that move, navigate obstacles, and adapt to their surroundings, without sensors, software, or external control. This research opens up entirely new possibilities for biomedical applications. The concept didn’t come from engineering theory, it came from watching animals move. Worms and snakes continuously reshape their bodies as they travel, allowing them to slip through complex terrain without conscious planning. Macroscopic robots have long borrowed this principle, but shrinking it down to the microscale had always hit a wall: small robots were rigid, and flexible robots were large. Kraft and Wei set out to close that gap. Their solution was a soft, chain-like structure made of flexibly connected segments, fabricated on a Nanoscribe 3D microprinter. Each element measures just 5 µm, with bar-joints of 0.5 µm connecting them. To put that in perspective, a human hair runs between 70 and 100 µm thick.…