Researchers Control Soft Robots Using Magnetic Fields

The magnetic field of magnetic particles in chains is useful for developing responsive materials soft robotics. Scientists from the North Carolina state University introduced iron microparticles into a liquid polymer mixture and applied a magnetic field to induce the microparticles to form parallel chains. Using such materials with greater complexity allows advanced functions.


Conventional robotic grippers struggle to handle items that are delicate and of varying size, shape, and weight. So, scientists had built soft robotic grippers to manipulate items of varying size, shape, and weight with a single device. Now scientists have built a method to control soft robots.

Scientists from the North Carolina State University have developed a fundamental advance in controlling so-called soft robots. They just used magnetic fields that remotely manipulate microparticle chains embedded in soft robotic devices.

Scientists primarily introduced iron microparticles into a liquid polymer mixture. Next, they applied a magnetic field to induce the microparticles to form parallel chains. It makes the mixture dry that leaves behind an elastic polymer thin-film. The film is embedded with the aligned chains of magnetic particles.

Through this chain, scientists could manipulate the polymer remotely as a soft robot by controlling a magnetic field. And, it directly creates an impact on the chains of magnetic particles. The chains of iron microparticles respond by aligning themselves. And the surrounding polymer in the same direction as the applied magnetic field.

Joe Tracy, an associate professor of materials science and engineering at North Carolina State University, said, “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. Possible applications for these devices range from remotely triggered pumps for drug delivery to the development of remotely deployable structures.”

Through this technique, scientists have created three kinds of soft robots. The first device is a cantilever that can lift up to 50 times its own weight. The second device is an accordion structure that expands and contracts the muscle’s nature. And the third device is a tube that behaves like a peristaltic pump.

Tracy said, “We’re now working to improve both the control and the power of these devices, to advance the potential of soft robotics.”

Along with this, scientists have also developed a metric for assessing the performance of magnetic lifters, such as the cantilever device. They developed it 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.

Co-author Ben Evans said, “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.”


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