Heat Engine - Nitinol Metal Engine driven by hot & cold water.

The Heat Engineis a very special kind of heat engine that demonstrates the conversion of heat energy into mechanical energy. Based upon the work of Dr. Alfred Johnson who was granted a patent on this type of heat engine in 1977 patent # 4,055,955

It uses the unique property of Nitinol alloy to generate mechanical motion from heat. Nitinol has trained into a shape at high temperature (about 600° C) 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 50° C to 70° C) 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.

See the Heat Engine in action!

More Information

Thermobile

This fully assembled Nitinol Heat Engine works like an engine without any visible power source. As a shape memory alloy, the Nitinol wire reacts to small changes in temperature converting low temperature thermal energy into mechanical energy and driving the engine as it tries to return to its "remembered shape".

The wheels of the Thermobile will continue to spin as long as it remains heated. To start the engine, simply immerse the edge of the smaller pulley into a water bath between 45 and 90 degrees Celsius and spin the larger pulley.

Specifications:

8" long x 1" thick, 4 oz.

Clear acrylic handle with aluminum pulleys and looped Nitinol wire.

Operating Temperature: 45 - 90 degrees Celsius. (105 - 200F)

Curie Effect Heat Engine

Explore the properties of Ferromagnetism and Curie points with this Curie Effect Heat Engine. Kit Includes:

• Nickel Curie effect enhanced wire (part of aluminum wire assembly)
• 1.5" Aluminum Wire Assembly
• Neodymium Disc Magnet 1"Diamter x 3/16" Thick
• Birthday Candle
• Brass Machine Screw & Nuts
• Wooden Side .75" x 4" x .25"
• Base 1.25" x 2" x .5"
• Steel Plate 1.25" x 3" x .032"

Construction Booklet (pdf 74K)

Video File 1 Heat Engine Test: Hi Res (544 Kb) Lo Res (208 Kb)

Video File 2 Heat Engine Running: Hi Res (1.5 Mb)Lo Res (488 Kb)

External Link - The Design, Construction and Testing of a Thermo-Magnetic Motor by Tim Raney