The robot is named “Meshworm” for the flexible, meshlike tube that makes up its body. Researchers created “artificial muscle” from wire made of nickel and titanium — a shape-memory alloy that stretches and contracts with heat. They wound the wire around the tube, creating segments along its length, much like the segments of an earthworm. They then applied a small current to the segments of wire, squeezing the mesh tube and propelling the robot forward...

Kim and his colleagues looked to the earthworm for design guidance. [emphasis mine - ed] They noted that the creepy crawler is made up of two main muscle groups: circular muscle fibers that wrap around the worm’s tubelike body, and longitudinal muscle fibers that run along its length. Both muscle groups work together to inch the worm along.

The team set out to design a similar soft, peristalsis-driven system. The researchers first made a long, tubular body by rolling up and heat-sealing a sheet of polymer mesh. The mesh, made from interlacing polymer fibers, allows the tube to stretch and contract, similar to a spring.

Science fiction writers have been thinking "worm-like robot" for a long time. In his 1962 story War With The Robots, sf great Harry Harrison predicts the development of the robot earthworm:

"...At the front end is a hard-edged orifice that drills a hole in the ground. Debris is carried back through the body of the machine and eliminated here: in operation it is not unlike the common earthworm. Directional apparatus here guides it, oriented by a gravimeter to locate our base. Here a power unit and here a frequency generator...

"They have no metallic components ... they move very slowly... we estimate they entered the ground four years ago."

I regret to note that Harry Harrison died this past week; we'll all miss him, but fortunately he left some great stories behind. I have just a few here on Technovelgy:

• Arm of the Law, Fantastic Universe, 1958
  
• Bill the Galactic Hero, Unknown, 1965
  
• Deathworld, Astounding Science Fiction, 1960
  
• Ethical Engineer, Analog, 1963
  
• I Always Do What Teddy Says, Bantam, 1965
  
• Robot Justice, Fantastic Universe, 1959
  
• Rock Diver, Hillman Periodicals, 1951
  
• Simulated Trainer, Fantastic Universe, 1958
  
• The Repairman, Galaxy Science Fiction, 1959
  
• The Robot Who Wanted to Know, Pyramid Books, 1962
  
• The Robots Strike, Fantastic Universe, 1959
  
• The Turing Option, Unknown, 1992
  
• The Velvet Glove, Fantastic Universe, 1956
  
• War With The Robots, Pyramid Books, 1962