Researchers at the University of Southampton have created a fish-inspired robotic fin that could help underwater robots move smoothly through turbulent water. By copying the way fish sense and respond to changing currents, the new design allows robotic vehicles to adapt to rough conditions instead of fighting against them.
Learning From Nature
Underwater robots often work in difficult environments where strong currents and swirling flows can easily disrupt their movement. Traditional robotic fins and wings are rigid, so sudden changes in water flow can push the machines off balance. As a result, robots must constantly correct their position, which wastes energy and reduces efficiency.
Fish, however, handle turbulence far better. They rely on sensitive biological systems that allow them to detect even slight changes in water movement. Then they quickly adjust their fins and body shape to stay stable and continue swimming smoothly.
Inspired by this natural ability, scientists designed a flexible robotic fin that can “feel” the surrounding water.
A Fin That Senses and Adapts
The new fin is made from soft silicone and contains tiny liquid-metal channels that act like sensors. When moving water bends the fin, these channels detect the deformation and send signals to a control system.
The robot then adjusts the stiffness and shape of the fin in real time using hydraulic pressure. Instead of resisting turbulence, the fin bends and adapts, helping the robot glide more naturally through the water.
More Stable Ocean Robots
During laboratory tests in a water tunnel, the adaptive fin dramatically improved stability. Compared with traditional rigid wings, the system reduced sudden force spikes caused by turbulence by about 87 percent.
Such technology could make underwater robots more reliable and energy-efficient. In the future, these improved machines may assist with marine research, inspect offshore structures, and explore deep-sea environments where stable navigation is essential.
