He’s every bit as awesome as “RoboCop.” Except, you know, he’s a clam.
Still, this new device–from Anette Hosoi, Amos Winter, and co-workers in MIT’s Department of Mechanical Engineering–is pretty nifty. It’s biomimetic, based on the digging behavior of the so-called “razor clam” (Ensis directus), a specimen of which is shown in the video, and to left in the photo, above. Elizabeth A. Thomson’s article at MITnews describes the research that led up to the invention:
Winter created a glass-sided box filled with water and beads, added a living clam, and watched the animal burrow. It turns out to be a multi-step process. The animal’s tongue-like “foot” wiggles down into the sand, then the animal makes a quick up-and-down movement accompanied by opening and closing its shell. Together these movements propel it.
By filming the movement of the beads, Winter made a startling discovery. The clam’s quick up-and-down, opening-and-closing movements turn the waterlogged “sand” around it into a liquid-like quicksand. Experiments showed that “moving through a fluidized substrate [the quicksand] rather than a packed granular medium [ordinary sand] drastically reduces the drag force on the clam’s body, bringing it to a point within the animal’s strength capabilities,” Winter reported.
Details about the device itself are scanty, other than that the clam-sized machine shown in the photo “is supported by a large apparatus of pressure regulators, pistons and more that control such things as how hard the robot is pushed in each direction.” Which leads me to speculate that the prototype, as shown, is unpowered and operated remotely by pneumatics or hydraulics. They’re envisioning applications as a lightweight anchor that could burrow into or out of a sea- or lakebed on command.