In addition to their pointy and painful spines, sea urchins have another impressive part of their anatomy: their mouths. A team of engineers at the Jacobs School of Engineering at UC San Diego have created a grabbing claw inspired by the mouth of the sea urchin, and in particular its highly durable reinforced teeth. The urchin-mouth claw could be instrumental in collecting ground samples from planets like Mars.
Sea urchin mouths are incredibly durable in large part because of the rugged environment they inhabit. Each of a sea urchin’s teeth is reinforced with a keel — a t-shaped structure that reduces stress on the tooth to increase longevity and durability. That’s how sea urchins can dig through the rocky terrain of the ocean floor, uprooting forests of kelp without being sidelined by the rocks or other obstacles that would stop other animals.
The UC San Diego engineers scanned a sample of pink sea urchins from the Pacific Ocean using three-dimensional microscopy imaging. From the 3D scan, they were able to build an accurate model of a typical sea urchin’s mouth and teeth, which led to a series of 3D prototypes of their claw invention. Their first prototype was extremely close to the sea urchin’s natural mouth, which enabled it to grind up tough rocks, but it missed finer particles like sand. A second prototype scooped up sand better thanks to flattened tooth ends, but the natural opening and closing motion that categorizes sea urchin grasping was out of whack.
Finally, the engineers kept the flattened teeth but reattached them to the base of the grabbing claw to allow for smoother opening and closing motions. Each of the prototypes was 3D printed, so making changes was a quick and precise process. The UC San Diego engineers hope that NASA or SpaceX might take notice of their tech, since they envision it being attached to rovers to collect soil samples from other planets.
