Smart Materials

1
Smart Materials
A smart fluid developed in labs at the Michigan
Institute of Technology. Source
www.cs.ualberta.ca/database/ MEMS/sma_mems/smrt.h
tml
2
What are Smart materials?

• Smart Materials respond in some way when an
  external effect such as light or temperature. The
  response can be reversed when the external effect
  is removed.
• Lets look at some examples.

3
Thermochromic pigments

• Thermochromic dyes are made from liquid crystals
  which change colour when heated.
• They are used on fabrics, novelty goods and in
  scientific applications, such as testing the
  temperature of food.

Source www.designinsite.dk
4
Thermochromic pigments

• On the left, the drink is too warm.
• Once cooled, a stripe appears (right) indicating
  that the drink is no properly chilled.

Source www.inkworldmagazine.com
5
Shape Memory Alloys (SMAs)

• SMAs are metals which can be deformed, but then
  return to their original shape when heated.
• The most common SMA is Nickel-Titanium.

Source www.designinsite.dk
6
Shape Memory Alloys (SMAs)

• A video showing how a Shape Memory Alloy returns
  to its original shape when heated.

Source www.cs.ualberta.ca/database/MEMS/sma_mems
/index2.html
7
Applications of SMAs

• SMAs are widely use in medical applications.
• This is a medical implant which expands when
  warmed to body temperature, to widen a restricted
  blood vessel.

Source www.bbc.co.uk/radio4/science/
thematerialworld_20020919.shtm
8
Pseudo-elastic alloys

• These materials become highly elastic when
  deformed and can then return to their original
  shape. No temperature change is required.
• These memoflex alloy spectacle rims are made
  from a pseudo-elastic alloy.

Source www.perret-optic.ch
9
Pseudo-elastic alloys

• Click on the image to view a manufacturers
  promotional video for Nitinol a pseudo-elastic
  alloy.
• Note Internet connection required for this

Click here to view Nitinol video
10
Electro-rheostatic and Magneto-rheostatic
materials

• These materials can change from liquid to solid
  when an electrical current or magnetic field is
  applied.
• The MR fluid is liquid when no magnetic field is
  present (left), but turns solid immediately after
  being placed in a magnetic field (right)

Source www.cs.ualberta.ca/database/MEMS/sma_mems
/index2.html
11
Smart grease

• Under normal circumstances, if the wheel is wound
  up and released, it will spin rapidly and slow
  down.
• If a tiny amount of smart grease is added between
  the friction surfaces, the wheel will turn at a
  uniform (very slow) speed and the stored energy
  will be released uniformly.

Source www.mutr.co.uk/Materials/Mat_smartgrease
.htm
12
The future

• Engineers are only just beginning to tap into the
  full potential of smart materials. There are many
  applications in aircraft manufacture.
• This image shows the use of smart wires to
  control aileron shape in a wing compared with
  hydraulic cylinders.

Source www.cs.ualberta.ca/database/MEMS/sma_mems
/index2.html
13
The future

• Scientists at NASA are investigating the use of
  smart materials to create aircraft that fly like
  birds and insects.

Insert NASA video clip after conversion to AVI
format
Source http//spacescience.com/headlines/images/w
ings/morphing_med.mov