6 - Technical Understanding Flashcards
(33 cards)
Give three types of colour-changing smart materials.
Thermochromic pigment, photochromic pigment, electrochromic material.
Where might thermochromic pigment be used?
Thermometers for children, colour-changing mugs.
Where might photochromic pigment be used?
Security markers that show up under UV light, glow-in-the-dark stickers.
Where might electrochromic material be used?
Liquid Crystal Displays (LCD), window glass with different tint settings for privacy screens.
Give two types of shape-shifting smart materials.
Shape memory alloys (e.g. nitinol), shape memory polymers (e.g. polymorph).
Where might shape memory alloy be used?
Dental braces, fancy glasses, shape-shifting aircraft wings.
What does polymorph do?
Can be easily moulded when heated, then remains in a rigid shape once cooled.
What is a motion control gel?
A gel that changes its viscosity to control the speed of objects moving through it.
Define viscosity.
A measure of a liquid’s resistance to an object moving through it.
Where might motion control gels be used?
Soft-closing drawers, earthquake dampening systems, adjustable vehicle suspension.
What are hydrophobic and oleophobic materials?
Self-cleaning materials. Hydrophobic is water repellent, which stops dirt from sticking to it. Oleophobic is oil-resistant, which helps remove fingerprints from surfaces.
Where might hydrophobic materials be used?
Self-cleaning windows, wall paint.
Where might oleophobic materials be used?
Screens for phones, tablets and ATMs.
How does self-healing concrete work?
Limestone-producing bacteria capsules are included in the concrete mix, water releases them to heal cracks.
Where might self-healing polymers be used?
Graphics cutting mats, chopping boards.
What is a sacrificial part?
A weaker part of a product designed to break first in order to protect more significant parts. (e.g. car bonnet, electrical fuse)
Give an example of a reinforced part.
Remote control casings might have extra material at the corners to stop the plastic there from thinning.
What is triangulation?
Adding cross-members to rectangular frames to make a triangular shape (improving stability).
Why might you add folds, ribs or webs to a product?
To improve rigidity.
Why are surface finishes used on products?
-To enhance appearance.
-To protect against decay/wear.
-Prevent the material absorbing moisture.
Give three examples of finishes used for wood.
Polyurethane varnish, wax and Danish oil.
What are the positives of polyurethane varnish?
-Provides tough, heatproof, waterproof finish.
-Clear finish (can still see wood grain).
What are the positives of wood wax?
-Available in clear & coloured.
-Increases surface hardness & toughness.
What are the positives of Danish oil?
-Maintains the natural appearance of the timber.
-Lots of coats builds up a matt, water-resistant finish.
