Researchers from North Carolina State University and Elon University have developed a new technique to remotely control and reconfigure soft robots. They were able to control the robots, lock them into one position, and reconfigure them so that they could become different shapes. The team of researchers were able to develop this with the use of light and magnetic fields.
Joe Tracy, one of the professors of material science and engineering at NC State and an author of the paper on the new research, spoke about the developments.
“We’re particularly excited about the reconfigurability,” he said. “By engineering the properties of the material, we can control the soft robot’s movement remotely; we can get it to hold a given shape; we can then return the robot to its original shape or further modify its movement; and we can do this repeatedly. All of those things are valuable, in terms of this technology’s utility in biomedical or aerospace.”
The soft robots that the researchers used were created out of polymer that was embedded with magnetic iron microparticles. Normally, this type of material is not flexible, and it stays in its shape. What’s different about the material that the researchers used is that when they heated it up by using light from a light-emitting diode (LED), the polymer became pliable.
The researchers then used a magnetic field to remotely change and control the shape of the soft robots. Once the robot was the shape that the researchers wanted, they removed the LED light. Once the light was removed, the robot became stiff again. This time, it was in the new shape. The LED light was then reapplied, and they removed the magnetic field. At that point, the soft robots were able to return to their original shape. If they didn’t want the robot to return to its original shape, they could apply the light again and use the magnetic field to create even more shapes.
These soft pliable robots have the potential to be used for many different things. The researchers were able to use them to lift and transport objects, and they were also used as cantilevers.
Jessica Liu, the first author of the paper, spoke about the new technique.
“We are not limited to binary configurations, such as a grabber being either open or closed,” she said. “We can control the light to ensure that a robot will hold its shape at any point.”
The researchers also created a computational model. This is able to be used to create a faster and more efficient soft robot design process. They are able to adjust the robot’s shape, polymer thickness, amount of iron microparticles in the polymer, and the size and direction of the magnetic field. This is all able to be done before they construct the prototype.
“Next steps include optimizing the polymer for different applications,” Joe Tracy said. “For example, engineering polymers that respond at different temperatures in order to meet the specific applications.”
The researcher’s paper was published in the journal Science Advances. It is titled “Photothermally Magnetically Controlled Reconfiguration of Polymer Composites for Soft Robotics.”
The co-authors include Jonathan Gillen, former undergraduate at NC State; Sumeet Mishra, former Ph.D. student at NC State; and Benjamin Evans, associate professor of physics at Elon University.