A team of researchers at Vrije Universiteit Brussel developed a special type of rubber that has the potential to be used in self-healing robots, according to a paper published in the journal Science Robotics in August 2017.
Researchers created a type of rubber that is strong enough to maintain its shape without internal support as well as soft enough to provide sensitivity. Such a rubber would not require the use of glues and screws for repairing, as the scar would not be as strong as the original material. On successful creation of such a rubber, the team of researchers proceeded to develop fingers for a robot using this unique kind of rubber. In case this rubber gets cut, it can be placed in an oven to heal at the temperature of 80° C for around 40 minutes. The high temperature causes the wound to close, thus initiating self-healing in the robot. The rubber is a polymer made of a network with cross links—a Diels-Alder reaction takes place, which creates bonds across a damaged area. The rubber must be left to cool down for a short period of time, after it has been heated, thus allowing the bonds to firm.
The team also created a gripper, which was a kind of artificial muscle on which they used this rubber, subjecting various cuts to this design to test the efficacy of self-healing. They created several devices using this technique and noted that all of them healed as expected and reported to be 98 to 99 percent functional post repair.
This process of healing could be repeated as many times as required, without imposing any degradation on the rubber.
This self-healing soft gripper has the potential to handle a variety of softs objects, including a rubber duck, mandarin oranges, and cherry tomatoes, without extensive human intervention.
This robot that self-heals in a way similar to that observed in human skin, when damaged shows immense potential for several applications where sensitivity is required such as lifting a patient at a hospital.