Shape-Shifting Robots Possible with New MIT Material

Shape-shifting robots, like something out of "Terminator 2," may be possible with MIT's newly developed material that can change between hard and soft states, according to recent research.

The material's design, developed by MIT in collaboration with Boston Dynamics, couples compressible foam on the inside with an external wax coating. With just a little bit of heating, the wax coating can change from a hard outer shell to a soft, pliable surface. Also, heating the wax allows the material to repair any damage it sustains.

"This material is self-healing," she says. "So if you push it too far and fracture the coating, you can heat it and then cool it, and the structure returns to its original configuration," Anette Hosoi, a professor of mechanical engineering and applied mathematics at MIT, explained in a statement.

And they chose internal foam because it can be squished into a small fraction of its normal size, and still bounce back to its original shape.

"This work is a great demonstration of how thermally controlled rigidity-tuning could potentially be used in soft robotics," added Carmel Majidi, an assistant professor of mechanical engineering in the Robotics Institute at Carnegie Mellon University, who was not involved in the research.

The invention was crafted as part of DARPA's Chemical Robots program, aimed to create "squishy" robots capable of squeezing through tight spaces and then expanding again to move around in a given area.

Researchers believe that robots built from the material, which is described in the journal Macromolecular Materials and Engineering, could also be used in search-and-rescue operations to squeeze through rubble looking for survivors, Hosoi says.

And because the robot is largely made of foam and wax, the material offers a rather inexpensive way to build advanced robotic technology.

Hosoi is now investigating the use of other unconventional materials for robotics, such as magnetorheological and electrorheological fluids. These materials consist of a liquid with particles suspended inside, and can be made to switch from a soft to a rigid state with the application of a magnetic or electric field.