Materiel that contracts or expands when electricity is introduced?

[Guest me6]

Is there a material that expands or contracts when electricity is introduced? For example if the material is in this shape 0 then electricity is introduced it turns into this o or vice versa. Thanks in advance.

[BPHgravity]

I do not know of any material exhibiting this phenomenon produced by electrical current alone, however, there is positive thermal expansion effects due to heat from electrical current.

[Cap'n Refsmmat]

That's why electricity makes wires buzz, I think. (that's what my science teacher says)

[BPHgravity]

Its not the conductors that buzz, its the connections at the terminations that do. Current causes an annealing effect at terminations that may eventually cause vibration. In most cases, the buzz you are hearing is from fluorescent luminaire transformers.

[Guest me6]

What i am thinking of is trying to replecate the human muscle. But by using electricity. Thanks.

[Skye]

MIT is doing something similar with polymers, but using chemical changes rather than electrical.

 

http://www.ai.mit.edu/projects/muscle/muscle.html

[YT2095]

yes there is, any material that exploits the Peizo electric effect does this

[BPHgravity]

yes there is, any material that exploits the Peizo electric effect does this

 

Huh? I don't think so. The piezoelectric effect causes some materials to become electrically polarized when they are mechanically strained. Applying electrical currents to a piezoelectric crystalline substance won't induce pressure or change?

 

 

I do recall reading about some sort of mineral laden gelly substance that "quivered" when elctrical currents were applied. I don't know what ever came of it.

[YT2095]

Huh? I don't think so. The piezoelectric effect causes some materials to become electrically polarized when they are mechanically strained. Applying electrical currents to a piezoelectric crystalline substance won't induce pressure or change?

you ARE just joking aren`t you?

the peizo electric effect works BOTH ways, and electrical signal will cause movement also, I think you understand only half of it here

 

one only need listed to a house alarm to know that a peizo transducer will indeed create movement!

[apathy]

so you are trying to make artificial muscle, eh?

usually conductive polymers like polythiophenes, polypyrroles or polyanilines are concocted in such a way, layers and whatnot to bring about electrochemical actuation

 

i sci-findered a few references if you have acess:

 

Synthetic Metals, 102(1-3), 1317-1318.

Sensors and Actuators, B: Chemical, B99(2-3), 525-531.

Sensors and Actuators, B: Chemical, B96(1-2), 152-156.

 

Cheers!

[Sayonara]

There was a rubbery fibre shown on Tomorrow's World a while ago that contracted and expanded when exposed to acids and alkalis respectively (or possibly vice-versa). That was supposed to be the next big step in artificial muscles, but as usual it seemed to suffer the kiss-of-death effect from appearing on that program.

[YT2095]

it`s just an idea, but maybe you could use Nitinol AKA "Memory Metal" in conjunction with a heating and cooling element, to make a reverse tensor (think bicep/tricep).

[DaveT]

The best material would be carbon nanotubes. With less than a volt, you can get major movement in the strongest and lightest material. It works in a wide variety of temps approx -185 to +1800. Look it up online, there are many pages on its properties including how to build them.

 

 

 

 

Is there a material that expands or contracts when electricity is introduced? For example if the material is in this shape 0 then electricity is introduced it turns into this o or vice versa. Thanks in advance.

[Enthalpy]

It's done currently with shape memory alloy (like Ni-Ti). Wires of such materials heat when a current passes, and the lengths changes - much more so than by thermal expansion alone.

[John Cuthber]

This is well established technology that you can buy off -the=shelf.

http://www.musclewires.com/AboutMuscleWires.php

(others are also available; that was the first one Google found for me)

If you need a lot of force or distance then things might be more difficult

[birsin]

Yes there are. They are commonly called aerogels or artificial muscles. They are currently being used mostly in solar cells because of the voltage needed to make them contract or expand. However, i was thinking, since robots have such a hard time walking, running, etc. with pneumatics and the current mechanics we use for their mobility, how come we cant make an accurate muscle group and whole robot with a similar muscle mapping to us with this material. And to compensate for the energy needed, the fibers could also act as solar cells. Unless this is already being tested or it's not capable of doing so.

 

http://www.nbcnews.com/id/29776085/

Edited February 17, 2013 by birsin