Nitinol memory wire experiment for kids

Nitinol memory wire is metal that remembers its original shape when heated (alloy of nickel & titanium). Experimenting with nitinol memory wire is fun like a magic trick, but it demonstrates physical principles of thermal energy and elasticity.

Safety note: Be sure to explain safety precautions to children. This experiment uses hot water. Eye and skin protection should be used. Disclaimer: All information provided on this site is for entertainment and education purposes only. Using any information from thecasabouquet.com is at your own risk.

Instructions for nitinol memory wire experiment

• Give the children 3 cups or bowls. You may want to use coffee cups to help with insulation. Label with a marker: hot, cold, room temperature.
• Ask the children to make observations of the nitinol memory wire and its qualities and make a sketch.

  

  

  
  
• Distribute water and ice cubes and water that is close to boiling. Record the temperature of each cup.
• Twist and bend the wire into a new shape.
• Put on safety glasses. 
• Use tongs to carefully lower the nitinol wire into the room temperature water. Observe and record the results.

What questions can you answer with an experiment like this? Does the shape you bend in the metal make a difference? Can you think of how it could be useful to have a metal that can be easily returned to its original shape? What inventions already exist? What could you invent?

Supplies

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• Safety glasses
• 3 cups or bowls
• nitinol wire 3 inch length or 12 inch length
• very hot water
• water with ice
• room temperature water
• tongs
• thermometer or temperature sensor
• paper towels,
• paper or notebook for recording results, pen

Tips for teachers: 1) I did not have hot tap water or a microwave available in my classroom. I tried to use the old immersion heating coil that is relatively inexpensive. I found it dangerously hot to use around children and it shorts out easily. My favorite was a plug in teakettle. It costs a bit more, but is safer, long lasting, and portable. 2) Children really do need to use caution with this experiment because the wire can fly into the air. With younger children, we used a large clear plastic box to help with shielding.

What is the science?

Content: thermal energy, elasticity, crystal structure

Nitinol is a silvery metal alloy made with nickel and titanium. It has shape memory from the combination of the crystal structures of the two metals. Its elasticity is 10 or more times that of other metals. Elasticity is the ability of a metal to return to its original size and shape after a distorting force is removed. There are a number of medical applications of nitinol, along with military, and industrial.

Resource links

• http://www.need.org/Files/curriculum/guides/IntScienceofEnergy.pdf
  • Science of Energy from need.org has a whole set of energy lab activities and worksheets
• http://www.vernier.com/products/sensors/temperature-sensors/
  • Temperature sensors from Vernier Software & Technology
• http://www.chemistrylearner.com/nitinol.html
  • Nitinol from Chemistry Learner
• http://www.physics4kids.com/files/thermo_transfer.html
  • Energy transfer from Physics 4 Kids
• http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch13/unitcell.php
  • Unit cells (crystals) from Purdue Chemistry
• http://www.flinnsci.com/teacher-resources/safety/general-laboratory-safety/
  • General Lab Safety resources from Flinn Scientific. Be sure to check out the Student Safety Contract.

I’ll be looking for comments below, or contact me at lisa [at] thecasabouquet[dot]com.

Affiliate links: if you make a purchase using these links, I’ll receive a small compensation towards maintaining this blog, at no extra cost to you.