A commonly available material exhibiting reasonable expansion/contract

[OtherRealm]

I am looking for a commonly available, non toxic material (i.e. on the market today for a relatively low price) that exhibits reasonable expansion and contraction in size when electricity is applied. This could be a gas, liquid, easily workable solid but ideally it would be a fabric or flexible rubber/plastic. I know there are jury-rigged (i.e., not currently on the market and requiring further development) ways of doing this using heat, I just was wondering if there is anything currently out there that would get the job done and ideally uses electricity directly and not through thermal expansion . Thanks.

 

[Simon Bridge]

Define reasonable? I'm guessing piezo-crystals are not?
What is it for?

i.e. imbedding dipoles in a block of rubber would make it stretch in an applied electric field.
Ferrofluids can be made to deform significantly in magnetic fields - which you can make with electricity.
The amount of stretching depends on the elasticity of the material - which would be an engineering problem.

For commercially available materials - try "artificial muscle" or "electroactive polymer".

 

[OtherRealm]

I am working on a robotics idea I had, and I would like to keep the cost within reason
I haven’t found anything that is commonly used (and therefore, I am assuming this implies there is nothing commonly available). I have found a recently published paper in Science (February) on using twisted nylon fishing line but so far I have been unable to duplicate their results using what I had lying around. I ordered some other thread that I’m going to try, but I didn’t want to go through a lot of effort if there is something already readily available.

 

[Simon Bridge]

I don't think there is anything you can just go down to the store and buy - except piezo-electric devices - you'd have to construct it out of other materials.
i.e. two small magnets, a plastic tube, and a rubber band - a solenoid at each end.