Breaking Up Isn’t Always Hard to Do
Researchers have created soft robots that can self-amputate and reattach their limbs, making them more versatile than traditional robots.
If you want a robot that can vacuum your floors, a little wheeled robot like those that are commercially available is probably your best bet. But if you want it to make your lunch, it would be of little use. You would instead need a robot with different sensors, algorithms, an arm, and more to get the job done. You would run into a similar situation with robots that are used in agriculture, medicine, and other areas as well. These systems are generally designed to do one thing, and do it well — and outside of those bounds they are about as useful as a paperweight.
When there is a lot of work to be done, this is very inefficient. Managing and maintaining a fleet of robots to carry out all of the tasks we want them to do would be a nightmare, and of course the expense would also be a major constraint. A team led by researchers at Yale University has developed a robotics system that may help robots to be more versatile in the future, however. Their method enables soft robots to remove and reattach parts of their body at will, giving them the ability to significantly alter their structure and the functions they can perform.
The technique was demonstrated on standard, soft silicone robots that are actuated by a bending of the material that occurs when internal air pockets are inflated or deflated by pumps. Where these new robots differ from those of the past is that they have very unique joints. Each joint is made up of a bicontinuous thermoplastic foam, in which the gaps in the foam are filled with a sticky polymer.
When these joints come into contact, the polymer sticks them together before hardening and making a strong connection. But when necessary, the attachments can be broken — as the polymer is heated with an electric current, it begins to soften and melt, which causes the joints to separate. The addition of the foam keeps the polymer in place so that it does not just form a puddle on the floor. This allows the process to be repeated in reverse to restore an attachment or create an entirely different configuration.
Reconfigurable robots are not entirely new, of course. But past designs typically relied on magnets or other rigid components to make the connections. But since even the joints of these new robots are soft, they can go where no rigid robot can, carrying out tasks like handling fragile objects, exploring confined spaces, or working in close proximity to humans in a safe manner.
In the following video, one of the team’s robots is shown crawling along until a rock falls on one of its legs, leaving it trapped. Then much like some reptiles and crustaceans can do, it self-amputates that leg to continue on its way. That is definitely something you don’t see a robot do everyday, and it could be a key piece of the puzzle that helps us to build more versatile robots in the future.