(U.S. patent #5,462,363)
Link: http://www.erikbrinkman.com/scroller/

In 1968, Sandia National Atomic Labs in New Mexico invented a nearly frictionless linear device which they called a "Rolamite". It has no rubbing, slipping or sliding (only very minimal rolling friction).

.... IT FEELS LIKE LIQUID MOTION ....

The Rolamite is now used in airbags and as the safety for the trigger in nuclear weapons. Sandia expected at the time that they would be able to achieve continuous ROTARY motion with this principle, but they never did.

Link: Rolamite Articles

I solved the rotary puzzle by creating what I call the ScrollerWheel. The implications are mind-boggling ! .... finally a "Rotary Rolamite".

Rotary Motion with friction SO low that many mechanical systems will no longer need bearings and .... never need grease .... ever. This completes the task begun in 1968 by Sandia and opens a new era with the first new mechanical principle to emerge in 350 years.

Link: Historical Comparison