Apple's obsession with magnets could mean better cooling for your next Mac

Ferrofluids + magnets = awesome cooling solution

Magnets ... just how do they work? Well, one company that seems to have a very good grasp on how magnets work is Apple, and the Cupertino giant is busy patenting technology that makes use of their odd properties.

I'm not usually a big fan of trawling through patents because companies tend to patent all kinds of weird and wonderful stuff, and most of the time it's done just to keep other from using the technology, but a patent uncovered the Patently Apple on magnet technology makes very interesting reading indeed. One bit in particular caught my eye, related to using ferrofluid for cooling:

Another twist relating to thermal management is presented in Apple's patent that deals with the use of correlated magnets in conjunction with a ferrofluid for a cooling system. According to Apple, as a ferrofluid is heated, its magnetic qualities decrease (e.g., it becomes less attracted to a magnet). Thus, a magnet near an element to be cooled will attract ferrofluid which will be heated by the element, thereby becoming less magnetically sensitive. The heated ferrofluid will flow away from the magnet and be replaced by cool ferrofluid. This cycle may continue indefinitely.

To me this is one of those 'why hasn't someone already thought of this?' ideas. It's absolutely brilliant. A magnet acts as a pump (a pump with no moving parts whatsoever, and needs no power or maintenence), and the ferrofluid acts as the coolant. Cool ferrofluid is drawn to the part that requires cooling and then as that ferrofluid warms up and becomes less magnetic, fresh cool ferrofluid replaces it.


This devices solves so many problems associated with cooling electronics devices:

  • A system like this would be small and self-contained.
  • It requires no power.
  • No maintenance system.
  • Sealed system, no risk of leaks (you definitely wouldn't want ferrofluid leaking inside your system because it would do immense damage).
  • Could be scaled up or down for different needs.
  • Far more efficient than vapor heat pipes currently used for cooling GPUs.

This is one of the most interesting patents to come out of Cupertino in a long time.