Soft robotic devices can be controlled using magnetic fields to remotely manipulate microparticle chains embedded in the robots, researchers at North Carolina State University found.
“By putting these self-assembling chains into soft robots, we are able to have them perform more complex functions while still retaining relatively simple designs,” says Joe Tracy, an associate professor of materials science and engineering at North Carolina State University. “Possible applications for these devices range from remotely triggered pumps for drug delivery to the development of remotely deployable structures.”
Researchers introduced iron microparticles into a liquid polymer mixture and applied a magnetic field to induce the microparticles to form parallel chains. This mixture was dried, leaving an elastic polymer thin film embedded with the aligned chains of magnetic particles. The direction and strength of the magnetic field can be varied. The iron microparticle chains respond by aligning themselves and the surrounding polymer in the same direction as the magnetic field.
The technique builds upon work in the field of self-assembling, magnetically actuated composites conducted by Tracy and Orlin Veley, the INVISTA professor of chemical and biomolecular engineering at North Carolina State.
“The chains allow us to manipulate the polymer remotely as a soft robot by controlling a magnetic field that affects the chains of magnetic particles,” says Tracy.
Tracy and his researchers created three types of soft robots using this technique. One is a cantilever that can lift up to 50 times its own weight. The second is an accordion-like structure that expands and contracts to mimic the movements of muscles. The third is a tube designed as a peristaltic pump. A compressed section travels down the length of this tube, much like someone squeezing out the last bit of toothpaste by running their fingers along the tube.
“We’re now working to improve both the control and power of these devices, to advance the potential of soft robotics,” Tracy says.
Filed Under: Materials • advanced