Robots are often characterized by their rigid frames and steel-like grip. However, researchers from Iowa State University have just published a study detailing the results of their latest soft robotics creation–robotic tentacles that are precise enough to coil themselves around the waist of an ant 400 microns wide, and soft enough to grab a delicate fish egg without deforming it.
The researchers working on the project say their aim is to develop robotic limbs that are soft and small enough to someday perform microscopic surgery. For example, robotic tentacles that could manipulate delicate blood vessels or even slip into our brains to remove tumors.
The tech behind these robotic tentacles
These eerie, but fascinating robotic tentacles were inspired by the limbs and appendages of octopuses, worms and starfish. Made from soft, elastic plastic and rubber, these robotic tentacles move in a spiraling manner to grab and squeeze objects, be they living or nonliving, much like elephant trunks, octopus arms and plant tendrils do.
These robotic tentacles consist of microscopic tubes 5 to 8 millimeters long whose walls are 8 to 32 microns thick and their hollow channels 100 to 125 microns wide. Putting these sizes into perspective, the width of a human hair is typically 100 microns.
Making these tubes involve dipping thin wires or optical fibers in liquid silicon rubber. Once the rubber solidifies, they are removed from the wires and fibers, leaving behind hollow tubes that can be inflated and deflated with a syringe. Also, as the rubber tubes dry, the effects of gravity ensure that their ends are thinner than their bases. When inflated, the thin side will bend more than its thicker base. The flexibility of these rubber tubes were further enhanced by fitting their exteriors with rings of silicon rubber that, according to study co-author Jaeyoun Kim, “amplif[y]the single-turn coiling into multi-turn spiraling.”
Adding more control, dexterity and functionality to such robotic tentacles will certain help conventional robotics overcome many of the obstacles of space and fragility. And in the realm of microsurgery, “the gentle spiraling and scooping motion of our micro-tentacle will definitely help.”