Wednesday, December 18, 2013

Check this out: Muscle wire

Have you heard of muscle wire?

It contracts when you pass current through it, heating it up, and returns to its original length when it cools.

It's made of shape memory alloy called Nitinol which undergoes a "reversible solid-state phase transformation known as a martensitic transformation" [Source: Wikipedia].

Have you used it? Post up your projects in the comments.


  1. It is neat stuff, I have a few lengths of it. It does have a few drawbacks, slow, low range of motion, only one way (you need to provide a counterforce) and draws a lot of power. But it's simplicity and strength/weight ratio and cheapness is just off the charts compared to other actuators. It is good for simple things like unlatching locks, for instance releasing all your weapons on your battlebot, or releasing landing gear on your ultralight airplane. where you don't need very fast cycling. miga motors makes self contained actuator modules with the stuff:

    1. John, thanks for the great info. I know muscle wire has been around several years now but I've not yet played with it. It's been on my "some day" list for a long time.