Smart Materials A smart fluid developed in labs at the Michigan Institute of Technology. Source: www.cs.ualberta.ca/~database/ MEMS/sma_mems/smrt.html

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. Let’s look at some examples.

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

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

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

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

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

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

Pseudo-elastic alloys Click on the image to view a manufacturer’s promotional video for Nitinol – a pseudo-elastic alloy. Note: Internet connection required for this Click here to view Nitinol video

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

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

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

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/wings/morphing_med.mov