Last week we wrote about how studying elephant trunks is helping scientists build more versatile robotics. Now, a group of researchers from the University of Colorado at Boulder has cracked the code on fish fins in the hopes that it will inspire similar design innovations.

Fin structure

Fish fins are unique in that they are quite thin and flexible, but also incredibly powerful. In fact, fins don’t contain any muscle, despite their ability to quickly propel fish in a different direction at any moment. Fish fins operate by twitching sets of muscles located at the base of the fins, and by using computer simulations and 3D-printed materials, the researchers were able to break down how these appendages are so efficient.

It turns out, fins are composed of multiple segments of a hard material that stack on top of much softer collagen. This gives them the perfect balance between flex and power.

“If you look at a fin, you’ll see that it’s made of many stiff ‘rays,'” said Francois Barthelat, senior author of the study. “Each of those rays can be manipulated individually just like your fingers, but there are 20 or 30 of them in each fin.”

Potential applications 

The researchers are confident that this knowledge can provide revolutionary inspiration in a variety of fields. In airplane design, for example, materials that are both stiff and flexible could be used to create wings that morph on command for improved maneuverability. This isn’t the first time aquatic creatures have inspired better design. Other studies have looked at how fish scales could be used to build better body armor and even more sustainable road salt.

Source study: Science Robotics – Segmentations in fins enable large morphing amplitudes combined with high flexural stiffness for fish-inspired robotic materials