4F30.60 Nitinol Engine


Heat engine, shape-memory alloy


A heat engine consisting of a loop of Nitinol wire running on two pulleys. When the smaller pulley is dipped into a cup of hot water the loop of wire rotates.



  • [1] Thermobile
  • [1] Mug
  • [1] Immersion heater or kettle
  • Water


  1. Boil the water using an electric kettle.
  2. Pour boiling water into a mug.
  3. Wait for 2 to 3 minutes until the water temperature drops to about 80 °C.
  4. Immerse the brass wheel about half way into the hot water and observe the wire rotates.


Additional Resources


  • We have a loop comprised of a length of thread and a short length of wire on two pulleys. At high temperature, the wire "wants" to be straight. If the wire is wound onto one of the pulleys and let go, the loop will rotate until the wire is off the pulley. The operation is not continuous.

Related AV

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If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.