New technique to control soft robots

An Indian-origin researcher from North Carolina State University has developed a novel technique for using chains of magnetic nanoparticles to manipulate elastic polymers in 3D which could be used to remotely control new "soft robots".

The ability to control the motion of soft robots, coupled with their flexibility, gives them potential applications ranging from biomedical technologies to manufacturing processes.

By applying a magnetic field, the researchers can control the way the nanocomposite bends -- making it a soft robot.

"Using this technique, we can create large nanocomposites, in many different shapes, which can be manipulated remotely," said Sumeet Mishra, PhD student and lead author of the paper.

"The nanoparticle chains give us an enhanced response, and by controlling the strength and direction of the magnetic field, you can control the extent and direction of the movements of soft robots," he explained.

The process begins by dispersing nanoparticles of magnetite -- an iron oxide -- into a solvent.

A polymer is then dissolved into the mixture, which is poured into a mold to form the desired shape.

A magnetic field is then applied, causing the magnetite nanoparticles to arrange themselves into parallel chains.

The solution is dried, locking the chains into place, and the finished nanocomposite can be cut, to further refine its shape.

The researchers believe this technique may be especially attractive for some biomedical applications as compared to soft robotics that rely on electricity or light for control.

"Electrical control can raise safety issues for some medical applications," Mishra added.

Both electrical and light signals pose challenges in terms of communicating those signals to devices embedded in the body.

"Magnetic fields, on the other hand, pass through easily -- and pose fewer safety challenges," he pointed out.

This technique uses inexpensive and widely available materials and the process is relatively simple and easy to execute, the researchers concluded in the paper appeared in the journal Nanoscale.