I’ve been remaking the Sound Reactive Nightgown and trying to make the Nitinol react more effectively. So I’ve been researching methods to shape or train the Nitinol to ensure it maintains a determined shape.
I’ve been experimenting with different diameters of Nitinol (aka Flexinol, memory alloy, muscle wire). I found that the thicker wire works best for moving fabric. Here you see a picture of .010″ diameter Nitinol but I recommend using 500 um or more (.019″+)
Training the Nitinol: Force the wire into your desired shape using pins on a metal plate, metal clamps, or metal wire to hold your Nitinol into shape. Heat the Nitinol under fire (I used my gas stove for about 10-20 seconds). Make sure you’re moving the Nitinol to heat it evenly.
Set the Nitinol aside to cool to room temperature. Do not undo the clamps until completely cool.
Place the Nitinol in ice cold water for 10 seconds or longer. Take the wire out and let it return to room temperature. Now you can remove the clamps and stretch out the Nitinol (Try not to force the wire too much at any time – this can make the wire weak and snap and this stuff is expensive!).
Place the flexinol into a bowl or plate. Pour boiling water onto the Nitinol. It should return back to your forced shape in an instant.
A video showing the trained Nitinol in action: http://www.youtube.com/watch?v=Y7jjqXh7bB4
This is a great link that gives info on Nitinol and training the wire: http://www.google.com/url?sa=t&source=web&ct=res&cd=12&ved…