Cuts being made into the legs of a soft robot produced using SHeaLDS, which resembles a four-legged starfish. Photo: Rebecca Bowyer/Cornell University.Engineers at Cornell University have created a soft robot capable of detecting when and where it is damaged – and then healing itself on the spot. They describe this self-healing robot in a paper in Science Advances.
“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 at Cornell University. “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?”
Shepherd’s Organic Robotics Lab had already developed stretchable fiber-optic sensors for use in soft robots and related components – from skin to wearable technology.
According to Shepard, for self-healing to work, the key first step is that the robot must be able to identify that there is, in fact, something that needs to be fixed. To do this, the researchers pioneered a technique that involves coupling their fiber-optic sensors 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. The resulting SHeaLDS – self-healing light guides for dynamic sensing – can produce a damage-resistant soft robot able to self-heal from cuts at room temperature without any external intervention.
To demonstrate the technology, the researchers used SHeaLDS to produce a soft robot resembling a four-legged starfish and equipped it with feedback control. They then punctured one of its legs six times, and showed that the robot could 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.
While SHeaLDS is sturdy, it is not indestructible. “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 plans to integrate SHeaLDS with machine-learning algorithms capable of recognizing 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”.
This story is adapted from material from Cornell University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.