"smatrt" wire

[bloody-orc]

well there is somekind of a wire that shrinks when electricity is going through it. anyone heard of it? well anyways where to get such a thing and also how to replace it and how is it made? and if someone has used it then how strong is it?

 

[tansis]

Nitinol wire is what you are looking for I believe, often called "muscle wire" or Flexinol , remarkable stuff.

NIhttp://www.nitinol.com/3tech.htm
NITINOL (an acronym for NIckel TItanium Naval Ordnance Laboratory) is a family of intermetallic materials, which contain a nearly equal mixture of nickel (55 wt. %) and titanium. Other elements can be added to adjust or "tune" the material properties

https://www.imagesco.com/catalog/nitinol/nitinol.html
Nitinol's physical function resembles biological muscle; when activated it contracts. To activate Nitinol it is heated above its transition temperature (typically 70C). An electric current may be passed through the wire to heat it electrically. When the material cools it can be stretched back it its original length.

Lots of linear applications, but this one displays some rotary thinking
https://www.imagesco.com/articles/nitinol/10.html

 

[bloody-orc]

woww thanks!
this is really extrodinary stuff and just what i have been looking for. thanks a lot