Smart / modern materials Flashcards
What is a Smart material ?
It is a material whose physical properties change in response to an input or change in the environment, such as electricity, pressure, temperature or light.
What are Thermochromic pigments ?
It is when hot and cold temperatures trigger a change of colour in special thermochromic dye
How can thermochromic pigments be used ( applications ) ?
Applications include:
- fever scan strips used on infants
- room thermometers
- children’s cutlery and crockery
- novelty goods and colour changing clothing
What are Photochromic pigments ?
It is when UV light stimulates particles in a special pigment
The effect only lasts as long as strong UV light is present
These pigments ae mainly used for novelty goods and colour changing paints
What are some applications of Photochromic pigments ?
- Lenses in sunglasses
- Security markers can only be seen in UV light
- Photochromic windows that change their transparency according to how much light there is
What are all the smart materials that you need to know ?
- Shape memory alloys - SMA
- Thermochromic pigment
- Phosphorescent pigment
- Photochromic pigment
- Electroluminescent wire
- Piezoelectric material
What are shape memory alloys and what do they do ?
They are metal alloys that can remember their shape when heated
If the shape of the object is changed it will return to its original shape when heat or a current is applied
What are the uses of a shape memory alloy ?
- Frames for glasses
- Greenhouse window openers
- Medical stents
- Orthodontic wires
What are phosphorescent pigments ?
Phosphorescence is a process whereby energy from the sun is absorbed by a ‘material’ and it is released slowly over a long time, in the form of light
The energy / light emitted is at a low intensity and this can last for many hours
Where are phosphorescent materials used ?
Uses:
- Glow-in-the-dark toys
- Stickers
- Paint
- Wrist watch
- Clock dials
What do piezoelectric materials do ?
It is when electrical charge is built up in response to mechanical stress
Or - generates a small electrical charge when sensors are compressed
can also generate movement when a electric charge is applied ( actuator )
What are the uses for Piezoelectric materials ?
Uses:
- Generating energy
- Sensors
- Burglar alarms
- Keyless car entry
- Seat belt sensors
- Actuators
- Digital cameras
What is Electroluminescent wire ?
Electroluminescent wire ( EL wire )
is a thin copper wire coated in a phosphor which glows brightly when a current is applied to it
EL wire is a portable light source that works to provide a bright, colourful glow that looks just like neon
What is the definition for a modern material ?
A material that has recently been developed for a specific application
What are all the modern materials that you need to know ?
- Graphene
- Metal foams
- Titanium
- Coated metals
- Liquid crystal displays ( LCD’s )
- Nanomaterials
- Teflon
- Corn starch polymers
