Smart Materials Flashcards
What is a smart material
Materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli
What is a Thermochromic material
Change colours at specific temperatures
Returns to original form after temperature is gone
Available as Plastic, Ink, Dyes for textiles, paint
Give some uses if thermochromic materials
Test strips on batteries, if in good condition when pressed at each end, current flows through printed resistor, heats it producing a colour change.
Colour indicators on mugs show wether substance is hot or cold
Baby spoons change colour when food is too hot
What is a shape memory alloy
When the material is bent or deformed, they will return to their original shape when heated
What are photochromic pigments
Change colour as the level of light changes
Give some uses for photochromic materials
Lenses in glasses that become lighter or darker depending on light conditions
Security markers that can only be seen in UV light
Photochromic windows can change their transparency depending on how much light there is
What is liquid crystal display
LCD is a laminated material of two laters of glass with a liquid crystal core
A thin flat panel that lets light through when a voltage is applied, or blocks the light when the voltage is turned off
When is LCD used
Digital watches
Flat screen televisions
What are nano-materials
The have tiny parts less than 100 nanometers in size
A nanometer is is one billionth of a meter
When are nano materials used
Used for surface coatings or thin films such as on computer chips
Also used in sports equipment, such as tennis rackets and golf shoes, where nano materials are added to make materials stronger while not increasing their weight
Nanoparticles are also used in clothing such as socks due to their antibacterial properties to reduce the absorption pf sweat
What are composite materials
`materials made form two or moe different materials, and combine the properties of the material they are made from
Give the earliest known composite material
Explain how it works
Bricks made from containing straw and mud
When dried, the mud is good at withstanding compressive forces but is prone to cracking, but when straw is added to the mix, it provides tensile strength which prevents cracking when the brick dries
Give an example of a particle composite
It is a mixture of cement, sand and stones; water is added during the manufacturing process.
What does GRP stand for
Glass Fibre Reinforced Polymer
What are GRP’s
What are they used for
Combines stands of glass fibres which are strong but brittle, with a flexible polymer
Hulls for yachts
Car bodies
