Soft robot demonstrates self-healing capabilities

The research team has created SHeaLDS – self-healing light guides for dynamic sensing – which creates damage-resistant soft robots that can self-heal from cuts at room temperature without any external intervention.

In order to ensure the self-healing process takes place correctly, the team developed a process that allowed the robot to identify when it has suffered damage. 

To do this, researchers have pioneered a technique using fibre-optic sensors coupled with LED lights capable of detecting minute changes on the surface of the robot. These sensors are combined with a polyurethane urea elastomer that incorporates hydrogen bonds, for rapid healing, and disulfide exchanges, for strength.

“Our lab is always trying to make robots more enduring and agile, so they operate longer with more capabilities,” said Rob Shepherd, associate professor of mechanical and aerospace engineering.

“If you make robots operate for a long time, they’re going to accumulate damage. And so how can we allow them to repair or deal with that damage?”

To demonstrate the technology, the researchers installed the SHeaLDS in a soft robot resembling a four-legged starfish and equipped it with feedback control.

Researchers then punctured one of its legs six times, after which the robot was then able to detect the damage and self-heal each cut in about a minute. The robot could also autonomously adapt its gait based on the damage it sensed. 

“They have similar properties to human flesh,” Shepherd said. “You don’t heal well from burning, or from things with acid or heat, because that will change the chemical properties. But we can do a good job of healing from cuts.”

Shepherd’s Organic Robotics Lab plans to produce more of these stretchable fibre-optic sensors, which could be very beneficial in the fields of robotics and wearable technology.

Eventually, the researchers want to integrate SHeaLDS with machine learning algorithms capable of recognising tactile events to eventually create “a very enduring robot that has a self-healing skin but uses the same skin to feel its environment to be able to do more tasks.”

The findings of the investigation were published in the journal Science Advances.