Home SCIENCE Nitinol Metallic Muscles with Shape Memory

Nitinol Metallic Muscles with Shape Memory


So today I will tell you about one unusual object – the paper clip. This clip is made from a very unusual material – nitinol. Nitinol is an alloy of nickel and titanium in proportions of 45% titanium and 55% nickel. This alloy has the unique property that was discovered in 1961 by American scientists.

source/image(PrtSc): Thoisoi2 – Chemical Experiments!

The property of this alloy is called “shape memory”. So to demonstrate this property let’s conduct an experiment.Take a clip of nitinol and deform it. Besides the clip I as well have a spring made of nitinol, which I also deform into a random shape.The activation temperature of nitinol is about 40 degrees Celsius.

I’ve turned on the burner on the stove and put the deformed Nitinol clip on its surface.Over time, while heated, the clip begins to return to its original shape. The same thing happens with the spring. This happens because when the temperature changes the crystal lattice configuration of nitinol changes from one phase to another.


Also, nitinol is 10 times more elastic than other metals. While nitinol restores the shape it can also do some work. Let’s see what kind of work a small spring of nitinol can make.I’ve attached the spring to a tripod and hung a porcelain basket on to it, which weighs 118 grams. Next, we stretch the spring. For the spring to be tightened again, I’ll heat it with a lighter. Let’s proceed. As you can see, the spring has lift the basket quite easily./Thoisoi2 – Chemical Experiments!