Presentation I had on

1. Smart Materials and their
Applications in Engineering
Dr. Mohammad Tawfik

2. Who am I?
• Aerospace Engineering Department
• Smart Materials and Structures
• American University in Cairo
• Communication and Leadership Skills

3. Why am I here?

4. To share the fun

5. And maybe … talk about
Smart Structures

6. Smart Material: What?
• Controlled change in properties
– Change in mechanical properties (MR fluids, SMA)
– Change in geometry (Piezoelectric, SMA)
• Energy Converters!
– Mechanical Electrical (Piezoelectric)
– Heat  Mechanical (SMA)
– Mechanical  Heat (Viscoelastic)
– Etc…

7. Smart Materials: Why?
• Vibration Damping
• Shape Control
• Noise Reduction
• Vibration/Damage Sensing
• Heat Sensing

8. Smart Structures: Classification
Wada, Fanson, and Crawly

9. Magnetorheological Fluids

10. MR Fluids
How do they work?
• Externally applied magnetic field
in a direction normal to the fluid
flow direction form dipoles in the
iron particles
• Magnetic poles start attracting
each others to the direction of the
field, hence forming chains
• The chains then form a skeleton
within the fluid, which gains the
fluid controllable yield stress

11. Why MR technology?
Mix them and you are done!
Required Materials to
synthesize an MR fluid:
• Lithium grease
 General purpose oil
 Micron-sized iron particles

12. Rabinow and Winslow 1950’s

13. • Some Videos

14. Seat Shock Absorbers

15. Shape Memory Alloy

16. Shape Memory Alloy
• Change mechanical properties with the
change of temperature
• Regain original shape when heated!

17. Shape Memory Alloys
• Some Videos

18. Application

19. SMA Embedding

20. Other Applications
• Dental Fillings
• Artificial Joints
• Heat Valves
• Eye-glasses!

22. Piezoelectric Materials

23. Piezoelectric Material
• Electric Field  Mechanical Strain : Actuator
• Mechanical Stresses  Electrical Potential
Field : Sensor

24. Basic Properties

25. Piezo-Fiber Composites

26. Active/Macro Fiber Composites

27. Energy Harvesters

28. MEMS Power Generation

29. Backpack Power Generator

30. Thank you for your attention!
Mohammad.tawfik@gmail.com
AerospaceEgypt.WikiSpaces.com
Facebook.com/AerospaceEgypt