Untethered microrobots actuated with focused permanent magnet field

This paper investigates the actuation of untethered microrobots with a focused magnetic field generated by a permanent magnet wand. The microrobots are chrome-steel spheres or Neodynium cubes with a size of 250 μm, which perform desired planar motions directed by the movement of the wand. We propose and evaluate novel methods to enhance the focused magnetic field of the wand by sharpening its tip, increase microrobot velocities via novel mechanical amplifiers, and reduce environmental forces via inexpensive anti-friction coatings. We document results of automated operation and teleoperated control of the microrobot during competition at the Mobile Microrobotics Challenge (MMC) held in 2013. Experimental results from the mobility and microassembly challenge indicate an excellent degree of precision motion control over the robot, at a price of a slightly lower maximum speed when compared to conventional electromagnetic actuation.© 2014 ASME