What is a smart material?
Should smart materials be called 'intelligent'
How can smart materials be used?

Pupils should:

(a) know that the term smart material has been given to a range of modern materials whose properties change with a change in the surroundings, such as changes in temperature, light, pH, etc, for example:

• thermochromic paint, which changes colour when heated
• photochromic paint, which changes colour on exposure to light
• shape memory alloy, such as NiTi or nitinol, an alloy of nickel and titanium, which has the ability to regain it's original shape when heated; uses include coffee-pot thermostat, superelastic spectacle frames, stents for veins, etc.
• shape memory polymer, which has the ability to regain its original shape when heated; potential uses include biodegradable surgical sutures that will automatically tighten to the correct tension and self repairing car bodies that will recover shape on gentle heating after a dent.
• polymer gels, such as hydrogels, have a cross linked polymer structure inflated with a solvent, such as water; the gel has the ability to swell or shrink (up to 1000 times in volume) due to small changes in, e.g. temperature or pH;

intended uses include artificial muscles, robot actuators, absorbers of toxic chemicals, etc.

(b) use given data to evaluate the social, economic and environmental impact of the use of smart materials.