Magnetic "Micro-robots"

These magnetic particles are manipulated by magnetic fields to open and close their pincers and pick up a glass bead to move it around. The particles lie at the interface between layers of oil and water. A magnetic field perpendicular to the interface causes the particles to form the clumps/"micro-robots" and a magnetic field parallel to the interface causes them to swim. So the next step is obviously to filter different beads from a mixed bag of them. And then, world domination.

Electret: The electric field equivelent of a magnet

So, magnets have permanent magnetic fields and electrets have a permanent electric field. Note that this is completely different than an electromagnet that generates a magnetic field due to an electric current. It seems like the main uses for these things are as sensors in microphones and dust collectors in air filters, but I think they have more potential, they just don't get the same attention that their magnetic counterparts do. They are made in an analogous way to ceramic magnets. A highly dielectric material melt is cooled and solidified in a strong electric field which aligns the molecules in the solid creating a permanent electric field.