Small, medium or large, a robotic fish maintains its swimming ability

The scalable robot ScaFi. 2026 CREATE Lab EPFL. CC BY SA-4.0. Propeller-powered underwater vehicles have long helped scientists explore and monitor aquatic environments. But they’re limited by their own mechanics: spinning blades can snag on vegetation, stir up sediment, and startle the wildlife they’re often sent to study, making them poorly suited to shallow creeks,…