[tt] the physics arXiv blog

[Eugen Leitl]

----- Forwarded message from the physics arXiv blog <howdy at arxivblog.com> -----

From: the physics arXiv blog <howdy at arxivblog.com>
Date: Wed, 28 May 2008 13:16:04 -0500 (CDT)
To: eugen at leitl.org
Subject: the physics arXiv blog
Reply-To: the physics arXiv blog <howdy at arxivblog.com>


[1]the physics arXiv blog

   [2]Friction-free sliding observed in nanoparticles

   Posted: 28 May 2008 12:34 AM CDT

   [3]Nanofriction 

   On the atomic scale, friction is a curious beast and explaining
   exactly how it arises (and why in certain circumstances it appears to
   be absent) has stumped tribologists.

   For the growing number of engineers designing and building
   nanomachines, one important question is how friction scales with the
   contact area between nanoscale components.

   In the macroscopic world, this is easy to answer: dry friction is
   independent of contact area, according to the second law of friction
   developed by the 17th century French scientist Guillame Amonton.

   Not so on the nanoscale, say Dirk Dietzel at the University of Münster
   in Germany and friends who have spent many happy hours measuring the
   force needed to push nanoparticles around using an atomic force
   microscope.

   And their results are at first glance quite counterintuitive. They say
   that in some circumstances the frictional force increases linearly
   with surface area. And, get this, in other circumstances friction is
   absent entirely.

   Friction free sliding is actually predicted between surfaces that are
   perfectly smooth, atomically flat and inert. That turns out to be
   feasible only for very small surface areas. The evidence for this
   effect has been patchy so far so Dietzel';s team can pat themselves on
   the back.

   More interesting perhaps is their assertion that the frictional forces
   they have measured are the result of contamination between
   nanosurfaces.

   What they're implying is that the problems that many engineers have
   with friction on that scale could be solved by reducing contamination.
   That's an interesting take. The only trouble is that cleanliness on
   the atomic scale is not a simple thing to achieve.

   Ref: [4]arxiv.org/abs/0805.2448: Frictional Duality Observed during
   Nanoparticle Sliding

   [5][arXivblog?i=1XaWEO] 
   [6][arXivblog?i=uxOwRH] [7][arXivblog?i=6LVBFH]
   [8][arXivblog?i=OlCDGh] [9][arXivblog?i=gC09KH]
   [10][arXivblog?i=wKsLOh] [11][arXivblog?i=NwHicH]
   [12][arXivblog?i=BjTadh] [13][arXivblog?i=QddpsH] 
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References

   1. http://arxivblog.com/
   2. http://feeds.feedburner.com/~r/arXivblog/~3/299596094/
   3. http://arxivblog.com/wp-content/uploads/2008/05/nanofriction.jpg
   4. http://arxiv.org/abs/0805.2448
   5. http://feeds.feedburner.com/~a/arXivblog?a=1XaWEO
   6. http://feeds.feedburner.com/~f/arXivblog?a=uxOwRH
   7. http://feeds.feedburner.com/~f/arXivblog?a=6LVBFH
   8. http://feeds.feedburner.com/~f/arXivblog?a=OlCDGh
   9. http://feeds.feedburner.com/~f/arXivblog?a=gC09KH
  10. http://feeds.feedburner.com/~f/arXivblog?a=wKsLOh
  11. http://feeds.feedburner.com/~f/arXivblog?a=NwHicH
  12. http://feeds.feedburner.com/~f/arXivblog?a=BjTadh
  13. http://feeds.feedburner.com/~f/arXivblog?a=QddpsH
  14. http://arxivblog.com/
  15. http://www.feedburner.com/fb/a/emailunsub?id=8632699&key=kesJ612ZsV
  16. http://feeds.feedburner.com/arXivblog
  17. http://feeds.feedburner.com/arXivblog

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-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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