Controlling soft robots using magnetic fields

A team of engineering researchers has made a fundamental advance in controlling so-called soft robots, using magnetic fields to remotely manipulate microparticle chains embedded in soft robotic devices. The researchers have already created several devices that make use of the new technique. “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 and corresponding author of a paper on the work. “Possible applications for these devices range from remotely triggered pumps for drug delivery to the development of remotely deployable structures.”

Specifically, the direction of the magnetic field and its strength can be varied. The chains of iron microparticles respond by aligning themselves and the surrounding polymer in the same direction as the applied magnetic field. The researchers have also developed a metric for assessing the performance of magnetic lifters, such as the cantilever device.

“We do this by measuring the amount of weight being lifted and taking into account both the mass of particles in the lifter and the strength of the magnetic field being applied,” says Ben Evans, co-author of the paper and an associate professor of physics at Elon University. “We think this is a useful tool for researchers in this area who want to find an empirical way to compare the performance of different devices.”