Metin Sitti and colleagues at the Carnegie Mellon University have developed a tiny swallowable robot that can anchor itself to the walls of your gut in order to snap images, deliver drug, perform biopsy, and so on.
Turns out, finding an adhesive that would stick to tissues without damaging them was very tricky, and the researchers found the solution ... in beetles and geckos!
Sitti and his lab group looked to beetles, which secrete oil-like liquids along their foot hairs in order to stick securely to surfaces. They coated their robot's feet with a similarly viscous liquid to "help get more adhesion by giving them a surface-tension component," says Sitti. Aside from increasing capillary and intermolecular forces, secretions help feet adhere to rough surfaces by filling in the gaps, he adds. [...]
Sitti's group is also mimicking gecko feet. Geckos have angled hairs on their feet that allow them to pull in one direction to adhere more securely, and in another direction to detach. "We made some angled fibers [where] in one direction friction is very high, and the other direction it's low," says Sitti. The group plans to put the angled fibers on the capsule robot in the future.