Could new 'self-healing' technique lead to invincible robots?

Robots are a step closer to Terminator-like invincibility after “wounds” in parts healed themselves, researchers have said.

Inspired by the soft tissue of humans and other organisms, the team from Vrije Universiteit Brussel in Belgium created a gripper, hand and artificial muscle out of rubbery elastomers. Capable of completing simple tasks, the robots can also “heal” damage when exposed to heat, potentially paving the way for resilient, long-lasting and eco-friendly new machines.  

Many believe soft robots hold promise for a wide range of tasks. Unlike harder devices made of metal or hard plastic, they can withstand mechanical impacts or change shape, making them suitable for rough terrain or tight spaces.

Despite their robustness, they are also susceptible to tears and punctures from sharp objects – something which the Brussels team set out to change using the heat-sensitive elastomers. In experiments, the researchers deliberately damaged the parts, making cuts in the material. When heat was applied, the parts sealed up and healed without leaving any weak spots.

“It is indeed like Terminator when he shoots the robot and it heals,” said researcher Bram Vanderborght to Professional Engineering. “But of course, robots are not just the mechanical parts, they are also the electronics. So maybe in the far future when everything is self-healable – also the sensors and the electronics – then yes it could be a bit like an invincible robot.”

However, Vanderborght said the robo-apocalypse is on hold for now because of one key feature – robots cannot regrow lost parts. Other challenges also face the healing process, which currently uses 80°C heat from an external source.

“While the material we use can be healed in theory infinitely, in practice if you overheat it then you get irreversible bonds and then of course healing will not work,” said Vanderborght. “Or if your surface gets contaminated then it’s also of course not so good, because then you have particles in it. The surface has to stay clean, it’s the same as a wound in a human.”

The team now plans to try different healing techniques, either internalising the heat source, using light-sensitive materials or using the cuts themselves as stimuli. Sensors could also detect tiny cracks and start preventative healing, said Vanderborght.

The research was published in Science Robotics.