IB Design Technology Topic A3.1.8: Smart Materials Key Definitions

Electro-rheostatic (ER) fluids are special liquids that can quickly become thicker or more solid when an electric field is applied. When the electricity is turned off, they go back to being a normal liquid. This makes them useful in things like shock absorbers and brakes.

Magneto-rheostatic (MR) fluids are special liquids that become thicker or more solid when a magnetic field is applied. When the magnetic field is removed, they return to their normal liquid state. This makes them useful in things like car suspension systems and vibration control.

Photochromic materials change color in response to light and revert when the light is removed.

A property of certain smart materials that allows them to generate a small electrical charge when mechanically deformed, and to change shape (expand or contract) when an electric current is applied.

A smart material that can be deformed and then return to its original, pre-set shape when exposed to a change in temperature or stress.

Materials that respond to external stimuli (such as heat, light, pressure, or electricity) by changing one or more of their properties in a controlled, reversible, and repeatable way.

Thermoelectric materials generate electricity when heat flows through two different conductors joined together. The temperature difference causes an electric current to form.