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Q & A: low friction coefficients

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Most recent answer: 08/29/2013
Q:
Coefficient of friction of two surfaces 0.1, is it possible to make the COF drop less? To values incredibly low like 0.01 or even 0.001? Without using ball bearings and such. Is it physically possible to do? I understand COF can never = 0. But can we decrease it to near zero values as much as possible?
- Ali
A:

You can certainly beat 0.1. Teflon's coefficient of friction with itslef or with some hard materials is around 0.04. I would imagine there are some solids with even lower COFs but can't think of any off-hand.

A quick check of graphite shows that a freshly cleaved surface can briefly have a COF of as low as 0.006.

Mike W.

p.s. Apparently our knee joints, including some fluid, are down in the range you'd like:
.  That engineering feat required a long development time.


(published on 08/29/2013)

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