1. Nitinol
Copyright © 2012 Board of Trustees, University of Illinois. All rights reserved.

2. Objectives
To investigate the unique properties of an alloy called Nitinol
To design an experiment using Nitinol
To understand the connection between Nitinol’s atomic structure and its physical characteristics
To learn about Nitinol’s applications
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3. Nanotechnology
Some scientists and engineers develop smart materials

4. Smart materials
Any material engineered at the nanoscale to perform specific tasks

5. Smart fabrics

6. Self-healing materials
Studied and made at University of Illinois
Can repair themselves
Can be used in cell phones and other devices

7. How self-healing materials work
Image from Sottos’ Nature article

8. Similar to epoxy

9. A smart alloy
NiTiNOL
Made of Nickel and Titanium at Naval Ordnance Laboratory

10. Nitinol—a smart material?
Bend it
Heat it
What happens?

11. Shape Memory Alloy (SMA)
Nitinol is a “shape memory alloy”
What does that mean?
What is happening at the nanoscale?

12. Phases of matter Solid Liquid Gas strong bonds weak bonds no bonds
Modified from a graphic found at

13. Martensite phase of Nitinol
Lower temperature
Very flexible
Can easily be deformed (changed)
Crop of graphic from
Modified fro ma graphic from
Deformed Martensite
Martensite

14. Austenite phase of Nitinol
Higher temperature
Rigid
Has defined shape
Crop of graphic from

15. Solid phases of Nitinol→
heat
Taken from

16. What you observed

17. What happened at the atomic level
Modified from graphics from 4applications.htm and

18. Nitinol
(Click on image to play.)

19. → Other ways to heat it? heat
Taken from

20. Can you “retrain” it?
Can you give Nitinol a new shape memory?

21. Properties of Nitinol Shape memory alloy Elastic
Does not react with water or oxygen
Can be used in the body

22. Austenite temperature
Slight difference in ratio of Ni to Ti can change the temperature from -50°C to +95°C
Engineered for different functions

23. How do you think Nitinol might be useful?

24. Medical applications Needles Orthodontic devices Guidewires Catheters
Stents
Stent picture from
Catheter picture from

25. Other applications

26. Summary Learned about Nitinol’s properties Heated it
Found other ways of heating it
Retrained it
Learned about its
applications