Has anyone developed a practical application using the Casimir effect?

The Casimir effect is the attractive force between two surfaces in a vacuum - first predicted by Hendrik Casimir over 50 years ago.

http://en.wikipedia.org/wiki/Casimir_effect

Was just curious if anyone has been able to harness this force for a practical application.


jj.inc6 years ago
Is this basically just a mico-gravity kind of thing. I always wondered why two things didn't pull together here on earth, but now I realize there is air in the way.

Anyway, I wonder if this is gradually pulling all the space junk together and making it easier for us to find a way to get rid of it.
kelseymh8 years ago
For the most part, the Casimir effect is an annoyance. In micro- and nanoscale mechanical applications, the attractive Casimir force has the effect of dramatically (exponentially) increasing the friction between nearby components. Some authors have argued that this effect is an insurmountable barrier to practical "nanomachines." However...

The Casimir effect is attractive between "infinite" parallel conducting planes (where "infinite" means "really really large" compared to the separation). For other surfaces or non-conducting materials, it may be attractive or repulsive. In particular, a recent article in Nature (you have to pay for the text, argh) confirms the existence of repulsive forces under appropriate conditions.

If this result is true, and if it can be generalized, then it may be possible to overcome the "friction" I described in the first paragraph by an appropriate choice of materials, component shapes, or/and immersion in fluids.
As far as I know, most current practical applications involve negating its effects, like its (very small) contribution to static friction.

Casimir repulsion is being looked at as a way to overcome friction in general. Casimir forces are also being looked at for controlling nano-gears and sensors. Theories of how it could be used are proliferating, but I am not aware of any applications that are definitively practical yet.

I expect some of its first 'real' uses will be doing the same things as in current experiments- measuring and controlling miniscule forces.

If you're interested in current developments of the nano-world, I suggest you take a look at van der Waals forces and MEMS.