RoboClam: Robot inspired by the razor clam's amazing digging powers

Mar 11, 2014
RoboClam: Robot inspired by the razor clam's amazing digging powers
Inspired by the amazing ability of the small clam to dig and wedge itself far deeper and more securely than would be thought, they show the robo-clam, a metal device on the right, anchored in sand in a testing device right next to a razor clam in the sand to the left. Credit: DONNA COVENEY

Warning: Don't try and stick this clam in your chowder. Scientists have built a robotic clam that isn't edible but could be incredibly useful, because it easily outperforms other commercial digging devices. This RoboClam, described at the American Physical Society meeting in Denver, could prove invaluable as low-energy anchors or as an environmentally safe way to lay down more intercontinental, undersea fiber-optic cables.

The Atlantic razor clam (Ensis directus) is a small, weak creature, about 4 to 8 inches in length. It has a weak squishy body that pokes, tonguelike, out of a long, narrow shell with a painfully sharp rim that looks like a closed straight razor (hence the nickname). And yet these clams can be hard to catch because of their remarkable burrowing ability - they can easily escape a hungry human digger.

The razor clam outstrips humans' mechanical diggers, too. When researchers compared the digging efficiency of the clam to commercial digging devices like anchors, it found that it was 10 times as efficient at digging as the machines on the market. This means it uses far less energy to get through such densely packed sand. But what gave the razor clam, not to put too fine a point on it, such an edge?

A team of researchers from MIT and the University of Maryland decided to find out.

"The idea was just to trust that nature has designed a good way to do this," said lead author Kerstin Nordstrom, a soft-matter physicist at the University of Maryland.

The scientists studied the and found that it digs quickly by "fluidizing" the sand it's digging into, making it act like a fluid rather than a solid. It does this by contracting its body and sort of sucking in, creating a vacuum that causes the sand to become unstable and start moving around. This fluidlike mix of grains and water is much easier to displace and dig through than a floor of solid, unmoving sand.

With this principle in mind, the researchers built a prototype that would fluidize the sand in the same way. Nordstrom and her colleagues used a mathematical model to check whether the RoboClam was properly fluidizing sand. They found that timing was key: start digging too quickly, and the sand wouldn't have enough time to "get up to speed"; start digging too late, and the would have already started settling.

The RoboClam, as they called it, worked as they predicted. Researchers are now building a larger version at MIT. Such efficient digging devices could be useful for ocean surveys or geological surveys or surveillance. That's because the relatively small robots charged with such work easily get pulled along with the current, but don't have a whole lot of extra energy to spare to anchor themselves to the ground. Bluefin Robotics, which supported the research, makes just the kind of robots that would benefit from such a low-energy anchor.

And as the Internet continues to grow, a clamlike digging device could be an environmentally friendly way to lay down more submarine data cables between continents, without bringing in large digging devices.

Explore further: An intersection of math and biology: Clams and snails inspire robotic diggers and crawlers (w/ Video)

4.8 /5 (12 votes)
add to favorites email to friend print save as pdf

Related Stories

Study uncovers secret to speedy burrowing by razor clams

May 25, 2012

(Phys.org) -- If you look at a razor burrowing clam sitting in a bucket, you’d never guess that it could burrow itself down into the soil, much less do it with any speed. Razor clams look like fat straws, ...

Robotic clam digs in mudflats

Nov 22, 2009

To design a lightweight anchor that can dig itself in to hold small underwater submersibles, Anette (Peko) Hosoi of MIT borrowed techniques from one of nature's best diggers -- the razor clam.

Razor clam research has a sharp edge

Apr 04, 2013

(Phys.org) —A barefoot encounter with a Razor Clam is not a pleasant experience, just ask anyone who has had their feet sliced open in the shallows of picturesque Lake Macquarie, north of Sydney.

Clam found to be over 500 years old

Nov 15, 2013

Further research following a field trip carried out by Bangor University's School of Ocean Sciences in 2006 has led us to identify the age of a clam more accurately.

Recommended for you

C2D2 fighting corrosion

1 hour ago

Bridges become an infrastructure problem as they get older, as de-icing salt and carbon dioxide gradually destroy the reinforced concrete. A new robot can now check the condition of these structures, even ...

Meet the "swarmies"- robotics' answer to bugs

7 hours ago

(Phys.org) —A small band of NASA engineers and interns is about to begin testing a group of robots and related software that will show whether it's possible for autonomous machines to scurry about an alien ...

Hitchhiking robot reaches journey's end in Canada

23 hours ago

A chatty robot with an LED-lit smiley face sent hitchhiking across Canada this summer as part of a social experiment reached its final destination Thursday after several thousand kilometers on the road.

Hitchhiking robot charms its way across Canada

Aug 15, 2014

He has dipped his boots in Lake Superior, crashed a wedding and attended an Aboriginal powwow. A talking, bucket-bodied robot has enthralled Canadians since it departed from Halifax last month on a hitchhiking ...

User comments : 0