1. By Chris Bomersbach MEEN 3344

2.  Buehler’s discovery of an NiTi alloy (Nitinol) in 1962, formed the basis for commercial use. Before then shape memory alloys had been observed but where not affective enough for practical use.  SMA’s have seen commercial use since the late 1980’s when they where first used for coupling on oil pipes.

3.  One way SMA’s are the most common type and can be deformed when cool, but upon heating, they return to their trained shape.  Two way SMA’s can be trained to have a cool shape as well as a hot one.  Different types include  Ag-Cd 44/49 at.% Cd  Au-Cd 46.5/50 at.% Cd  Cu-Al-Ni 14/14.5 wt.% Al and 3/4.5 wt.% Ni  Cu-Sn approx. 15 at.% Sn  Cu-Zn 38.5/41.5 wt.% Zn  Cu-Zn-X (X = Si, Al, Sn)  Fe-Pt approx. 25 at.% Pt  Mn-Cu 5/35 at.% Cu  Fe-Mn-Si  Pt alloys  Co-Ni-Al  Co-Ni-Ga  Ni-Fe-Ga  Ti-Pd in various concentrations  Ni-Ti (~55% Ni http://en.wikipedia.org/wiki/Shape_memory_alloy

4.  This video of one way Nitinol can give you an idea of just how effective it can be compared to conventional metals.  http://www.youtube.com/watch?v=fsBHF_j2 FJ4&feature=related http://www.youtube.com/watch?v=fsBHF_j2 FJ4&feature=related  Nitinol can also be returned to it’s original shape by sending an electric current through it. As it resists the electricity, it becomes heated.

5.  The most common commercial application involves the pseudo-elastic property during it’s high temperature state.  This includes eye-glasses, cell phone antennas, and so on, which are experiencing their high temperature state at room temperature.

6.  In the future, if significant steps can taken in cost reduction, SMA’s will be used for almost every metal object. Mail boxes could pop back into shape on a sunny day. That slinky you had as a child would have lasted longer then thirty minutes.  Imagine getting into a car wreck, then only needing to hold a torch to your vehicle to repair the damage.  There are endless new uses for Biomedical applications, such as surgical equipment and mechanical devices.  There could also be morphing airplanes and submarines that could increase efficiency at different speeds.

7.  http://www.bio-medicine.org/biology- technology-1/Re-Shaping-the-Future-with- Shape-Memory-Alloys---SMA-Starter-Kit- 10282-1/ http://www.bio-medicine.org/biology- technology-1/Re-Shaping-the-Future-with- Shape-Memory-Alloys---SMA-Starter-Kit- 10282-1/  http://www.prudentpressagency.com/modul es/news/article.php?storyid=8180 http://www.prudentpressagency.com/modul es/news/article.php?storyid=8180  http://smart.tamu.edu/ http://smart.tamu.edu/  http://www.stanford.edu/~richlin1/sma/sm a.html http://www.stanford.edu/~richlin1/sma/sm a.html