posted on 2023-12-01, 15:04authored byAngus Unruh, Ethan J. Savage, Ayusman Sen
The design of functional nano/micro machines capable
of carrying
out complex tasks is an area of great current interest. Achieving
this goal requires control of their motion trajectories on demand
with precision. The addition of asymmetrically placed nickel stripes
to chemically powered gold–platinum disks allows for precise
control over particle motion through the application of magnetic fields.
These electrophoretic particles are typically too large to move due
to their aspect ratio and instead fall flat on one side. However,
the particles can be oriented vertically using a magnetic field, allowing
them to autonomously move through their environment. By utilizing
multidirectional magnetic fields, we demonstrate how the motion of
these particles can be initiated or stopped on demand and how their
trajectories can be directed into specific patterns, such as orbital
or rotational paths including sudden changes in direction or reciprocal
motion. The particles can also pick up and move multiple cargo particles
that are heavier than their weight.