Lucas Zeer, Software Developer and Nanotechnology Engineer, working at SciBots, is experimenting with Digital Magnetofluidics Devices. He built a first prototype of a FerroBot and is now developing a control board for it.
Magnetofluidics technology looks quite promising and could also be used in biology in combination with magnetic beads or with some kind of parafluids. Paramagnetic fluid or “parafluid” is a fluid that is attracted to a magnet.
For the experiment in this video the surface is covered with nanowires.
The FerroBot for now is not using any coatings (just a glass petri dish). The mineral oil base ferrofluid that Lucas is using is hydrophobic itself: Oil base ferrofluid suspended in 50/50 rubbing alcohol and water + a bit of sugar (which helps it not stick as much according to some people on stack overflow).
Interesting research and I am sure we will see more from Lucas as he is now even looking into Surface Plasmon Resonance (SPR) as a Biosensor for Smart Phone Platforms.