Scientists have developed a material that can switch between hard and soft states, which they say could enable the creation of low-cost, morphing robots.
Developed as part of a research project with Boston Dynamics, the Google-owned robotics company, the material was built with wax and foam by researchers from MIT, Max Planck Institute for Dynamics and Self-Organization and Stony Brook University.
Likening the technology to that of the T-1000 robot from the movie Terminator 2: Judgement Day, an MIT release suggested that the material could be used to create robots for rescue operations.
Robots built of the material would be able to squeeze through narrow gaps, such as rubble in collapsed buildings, and then re-expand to provide assistance to trapped survivors.
The project started with the idea of creating a “squishy” robot to get through tight spaces, but soon developed into the creation of a material that could switch between properties.
This was because of the need for control by the robot: something that would be very hard to achieve if it was always soft.
“You can’t just create a bowl of Jell-O, because if the Jell-O has to manipulate an object, it would simply deform without applying significant pressure to the thing it was trying to move,” explained MIT mechanical engineering and applied mathematics professor Anette Hosoi.
A phase-changing material that could switch between hard and soft was decided upon as the best solution.
“If you’re trying to squeeze under a door, for example, you should opt for a soft state, but if you want to pick up a hammer or open a window, you need at least part of the machine to be rigid,” said Hosoi.
The material is a foam 3D grid structure coated in wax. The foam can be squeezed into a far smaller space and will always bounce back, making it an ideal solution for the material.
The wax coating is what enables the material to switch between states: while cold it will remain hard and rigid, but when heated will soften and enable the structure to be squashed.
The researchers have proposed that this could be achieved by running wires along the struts of the lattice shape, with an electrical current applied when the wax needs to be heated.
By using such readily available materials, the researchers believe that the technology will be cheap to manufacture.
“A lot of materials innovation can be very expensive, but in this case you could just buy really low-cost polyurethane foam and some wax from a craft store,” said Nadia Cheng, who worked on the project as a former graduate student of Hosoi.
The technology may be some way from being a commercial reality, but with such cheap materials shape-shifting robots could become a ubiquitous part of our future.
Featured image: screenshot from Terminator 2: Judgement Day. Inline image one courtesy of MIT.