Magnetic repulsion is a force that can make things levitate. This is the principal behind maglev trains and an emerging breed of wind turbine. The advantage of magnetic levitation is the fact that physical friction is cut drastically or eliminated entirely--stuff no longer has to touch at all. When something must spin with ease, ball bearings have been the tech of choice, but this may be changing. Magnetic bearings, which use the principal of magnetic levitation, could be easing in with a cleaner and greener edge.The New York Times recently ran an interesting piece on a company that is trying to make magnetic bearings an off-the-shelf item. Magnetic bearings have been around for a while, but a Virginia-based company, Synchrony Inc., has taken what is typically a snarl of wires and control boxes, and bundled it all into a single, ethernet-connected unit. Magnetic bearings have the potential to be cleaner (since they don't depend on toxic liquid lubricants) and more efficient (no physical friction means less wasted energy).
You won't likely be buying magnetic bearings for your longboard anytime soon (they're highly specialized and in the tens of thousands of dollars), but they are already at work in big, stationary applications like HVAC chillers and gas turbine engines, where propellers need to spin with the utmost efficiency and every little bit counts.
"Magnetic bearings may play an increasingly important role in future industrial systems, including environmentally friendlier ones. The low-friction technology of these bearings eliminates the need for lubrication to keep a system operating smoothly," writes Anne Eisenberg in her article. What she does not mention is that wind turbine manufacturers (especially the Chinese, it seems) are getting keen on magnetic technology as a way to make wind generators more sensitive to temperamental air currents. Some proposed designs defy convention altogether.
While still more pricey than ball-based bearings, Victor Iannello, the chief executive of Synchrony, says that over the longrun, magnetic bearings are cheaper than their greasy cousins, despite the higher upfront cost.