Robo-earthworm squeezes through tight areas, survives blows

After observing how earthworms can squeeze through tight spots and survive heavy blows, researchers have built a robot version of the animal, with possible applications ranging from medicine to rescue and reconnaissance.

 

Researchers said the robot, dubbed "Meshworm," can move forward via peristalsis, or squeezing and stretching muscles along its body.

 

"Meshworm" is made almost fully of soft materials and is resilient, being able to continue moving even after being trampled on, according to the Massachusetts Institute of Technology (MIT), whose researchers were involved in the project.

 

Sangbae Kim, Esther and Harold E. Edgerton Assistant Professor of Mechanical Engineering at MIT, said such a soft robot may be useful for navigating rough terrain or squeezing through tight spaces.

 

“You can throw it, and it won’t collapse. Most mechanical parts are rigid and fragile at small scale, but the parts in Meshworms are all fibrous and flexible. The muscles are soft, and the body is soft … we’re starting to show some body-morphing capability,” said Kim.

 

Aside from Kim, the paper’s authors are graduate student Sangok Seok and postdoc Cagdas Denizel Onal at MIT, associate professor Robert J. Wood at Harvard, assistant professor Kyu-Jin Cho PhD ’07 of Seoul National University, and Daniela Rus, professor of computer science and engineering and director of MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL).

 

Aside from MIT, researchers from Harvard University and Seoul National University also took part in engineering the robo-earthworm.

 

The team recently published details of the design in the journal IEEE/ASME Transactions on Mechatronics. Their research was supported by the U.S. Defense Advanced Research Projects Agency.

 

Useful applications

 

Kellar Autumn, a professor of biology at Lewis and Clark College, said "Meshworm" may have many useful applications, such as next-generation endoscopes, implants and prosthetics. 

 

“Even though the robot’s body is much simpler than a real worm — it has only a few segments — it appears to have quite impressive performance,” Autumn says. “I predict that in the next decade we will see shape-changing artificial muscles in many products, such as mobile phones, portable computers and automobiles.”

 

A separate article on BBC said the engineers noted a worm-like motion helped reduce the noise such machines produce, making them suitable "for reconnaissance purposes."

 

BBC added "Meshworm" is one of several animal-inspired projects being funded by DARPA.

 

It said other projects include a robotic "cheetah" that can run at speeds of 18mph (29 kph), a micro-aircraft equipped with a camera that looks like a hummingbird, and AlphaDog - a four-legged robot designed to carry soldiers' gear.

 

Artificial muscle

 

Researchers created “artificial muscle” from wire made of nickel and titanium. This is a shape-memory alloy that stretches and contracts with heat.

 

The wire was wound around the tube, creating segments along its length, much like those of an earthworm.

 

A small current applied to the wire segments can squeeze the mesh tube and have the robot move forward.

 

While a significant challenge in soft robotics has been to design soft motors for such robots, the researchers behind "Meshworm" took a cue from the earthworm's muscle fibers that work together to inch the worm along. 

 

Kim and his colleagues developed algorithms to carefully control the wire’s heating and cooling to direct the robot worm to move in various patterns. 

 

To test its resiliency, the researchers hit the robot with multiple blows from a hammer, and stepped on it to test its durability.

 

"Despite the violent impacts, the robot survived, crawling away intact," the MIT said. — TJD, GMA News