EPFL and NYU release scalable biomimetic robotic fish ScaFi, whose swimming gait remains consistent across a nearly fivefold change in body length

An EPFL and NYU team published ScaFi in npj Robotics, a biomimetic robotic fish based on the tail-swinging motion of cod and mackerel, scaled up by simply thickening a fiberglass tail rod proportionally. The team built three sizes—0.6, 1.1, and 2.9 meters—and tested them in a creek and Lake Geneva; after normalization by body length, the swimming gait was largely consistent. The largest model has lower energy efficiency and needs a stronger motor, while under disturbance the smaller models are more agile but recover more slowly.