Selective
actuation of the side arms of a soft robot in a horizontal uniform
magnetic field.
Image credit: Sumeet Mishra.
(December 18, 2015) Researchers
from North Carolina State University have developed a technique for using
chains of magnetic nanoparticles to manipulate elastic polymers in three
dimensions, 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. Researchers are interested
in using magnetic fields to control the movement of these soft robots because
it can be done remotely – the control can be exerted without physically
connecting to the polymer – and because magnetic fields are easily obtained
from permanent magnets and electromagnets.
Chained magnetic
polymer nanocomposite. Image credit: Sumeet Mishra.
A team of researchers has now found a way of embedding long
chains of nanoscale magnetite particles in sheets of elastic polymer to form a
magnetic polymer nanocomposite. By applying a magnetic field, the researchers
can control the way the nanocomposite bends – making it a soft robot.
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.