What materials is compressed by applying electricity?

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Request for Question Clarification by pafalafa-ga on 18 May 2004 20:19 PDT

The phenomenon you are asking about is probably piezoelectricity.  

Certain crystals produce electricity when squeezed, and the effect is
reversible.  When an electric charge is applied, the crystals will
change shape a tiny bit.  The distortions can include a compression
change.

Is this what you are asking about?  I'd be glad to give you an
overview of the distortion effects in piezoelectric materials, and
identify some of the relevant materials.

But I am not aware of materials that *only* compress.  Rather,
compression is one possible type of distortion the materials can
undergo.

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Clarification of Question by samuelholl-ga on 19 May 2004 07:00 PDT

I'm interested in materials that compress much more than a
piezoelectric crystal. (to over 50% of their volume.)
Also the material should relax to it's original volume when the
electricity is released.

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Request for Question Clarification by pafalafa-ga on 19 May 2004 07:05 PDT

Hmmm.  I can't think of any materials that behave in quite the manner
you're describing.  It will be interesting to see if another
researcher can come up with something to meet your needs.

Good luck.

pafalafa-ga

piezoelectric crystal generally only change shape by a small amount (a
couple percent or less) when a voltage is applied.  I seem to recall
reading about some kind of polymer gel which changed shape by a larger
amount (though still I think less than 50%) and was under
consideration for "artificial muscle" for robots.

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