Rarely is a flexible image conjured when thinking of robots. The term ‘robot’ is mostly associated with rigidness, with joints and hinges that squeak on. The new Meshworm, an innovative robotic worm, therefore breaks preconceived notions of robots with fresh force.
A team of researchers from MIT, Harvard University and Seoul National University (SNU) developed in early August a robotic earthworm called Meshworm.
Apart from looking disturbingly like an earthworm, it is a useful robot because of its soft exterior, which can be used in areas that are hard to reach, or terrains that are rather bumpy for ordinary robots. Also, because it is soft, the worm can fit through small holes, even those smaller than the diameter of its body. Furthermore, despite its pliable exterior, the earthworm robot is extraordinarily tough. It can survive blows from a hammer and can resist being compressed.
The team leader, Sangbae KIM, stated that “You can throw it, and it won’t collapse. Most mechanical parts are rigid and fragile on a 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.”
The Meshworm’s movement is like that of the earthworm. It is able to twist and twirl so freely because of the material of which it is made. Researchers carefully chose to make it by winding a wire of a special nickel/titanium memory alloy around a mesh tube.
This wire is capable of contracting and expanding in different segments along its length, working as a muscle. The movement is based on peristalsis, the rhythmic expansion and contraction of muscles that can be seen in snails, sea cucumbers, and even in the human esophagus. Inside it is a small battery and circuit board that runs a computer algorithm.
This whole package sends an electric current through the wires, heating the wires and causing them to contract. It is the alternation between heating and cooling that makes the robot move like a worm and crawl forward.
While the Meshworm is not the first attempt at making a wormy robot, it differs in its simple design. All it needs to start moving is some circuitry, a set of wires that coil around the body to allow it to contract.
The Meshworm could be applied to several possible fields. It could be suited for endoscopes, implants and prosthetics. As mentioned above, it would be efficient in dealing with uneven landforms and fitted corners.
A type of ‘soft robot’, the Meshworm embodies the idea that to function outside the lab in the real world, softness is a very desirable quality. Humans can interact more naturally with soft robots because they are easier to handle, without any sharp edges that could cause discomfort or pain.
The combination of both soft and hard is needed, even in hard robots if they want to develop a true sense of tactility. As Kim states, “Just feel your palm. That is softer than any rubber you’ve seen in this world.”
Written by OH Jung Eun, SNU English Editor, josefinaoh@snu.ac.kr
Reviewed by Eli Park Sorensen, SNU Professor of Liberal Studies, eps7257@snu.ac.kr
Proofread by Brett Johnson, SNU English Editor, morningcalm2@gmail.com