Massachusetts Institute of Technology researchers, with the help of 3D printing, have developed a material that can switch between hard and soft. The material is described in a paper in the “Macromolecular Materials and Engineering” journal. It was developed by a team led by Anette Hosoi, a professor of mechanical engineering and applied mathematics at MIT, and is made of wax and foam.
The material was created based on the needs of Defense Advanced Research Projects Agency (DARPA). The agency wanted researchers to create robots that were octopus-like in that they could squeeze through tight spaces and then expand again. After much consideration, the research team decided that the only way they could meet DARA’s needs was to come with a material that could switch between being hard and soft.
“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,” Hosoi said to MIT News.
To create a material that was able to be “squishy” and rigid, the research team turned to foam and wax. They chose foam because it can be compressed, so that it is smaller than its normal size. They chose wax because it is hard when cool, but flexible when heat is applied. Creating the first batch of material was pretty simple. The research team dipped ordinary polyurethane foam in melted wax. Next, they encouraged the foam to soak up the wax by squeezing it.
During the next testing phase, the researchers 3D-printed the foam that they used in a lattice pattern instead of using regular polyurethane foam. They found that the 3D-printed foam worked better, perhaps because the research team was able to design the structure of the foam. The way in which they enabled the material to harden or soften was by heated it via copper wires.
A potential application of the material is use in surgical robots. Because robots made of this material could change states at will, they would be able to move through a patient’s body without damaging it. Search and rescue missions are another potential use of the new technology. Robots made of the phase-changing material would be able to go where human emergency responders cannot, looking through rubble, for survivors during catastrophes.
Now the research team is looking into using other materials that can be used for robotics in a similar way as the wax/foam combination. According to MIT News, the researchers are looking at fluids that have particles suspended inside them to see if they too can be made to switch from soft to hard in the presence of a magnetic or electrical field. Let’s hear your opinion on this 3D printed material in the shape shifting material forum thread on 3DPB.com. Check out the video below showing the material in action.