Nitinol Heat Engine

Powered By Hot and Cold Water

Demonstrate the conversion of heat energy into mechanical energy with this working engine. Based upon the work of Dr. Alfred Johnson who was granted a patent on this type of heat engine in 1977, this model uses the unique property of Nitinol alloy to generate mechanical motion from heat.

Nitinol has trained into a shape at high temperature (about 600ºC) and allowed to cool to room temperature, where it can be easily deformed and welded into a loop. When heated above a transition temperature (in this application about 50ºC to 70ºC) the Nitinol object abruptly returns to its high-temperature shape with a substantial force that is able to drive the pulleys and thus create motion. This interesting demo of basic physics is simple to operate - just use hot and cold water.