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Polymers. Metals. Materials. Timber . Ceramics. Composites. Smart materials. Smart Materials. What are Smart Materials?.
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Polymers Metals Materials Timber Ceramics Composites Smart materials
What are Smart Materials? Materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli, such as stress, temperature, moisture, pH, electric or magnetic fields.
Task Create a mind map of the different smart materials Using your mind map Think of 3 questions which can be used as a test at the end of this lesson
Thermochromic pigment Interesting gimmicks ! Inks that change colour with temperature Has your egg been hot enough for long enough? Useful on marketing materials A temperature gauge
Photo chromatic pigment Applications such as sunglasses, anti-flash visors, sun-blocking products and radiation indicators A pigment that can be added to plastics or paint to make it change colour depending on changes in UV levels • Energy-efficient windows that switch from transparent to opaque spontaneously upon exposure to increasing levels of sunlight
Electro-rheostatic (ER) and magneto-rheostatic (MR) materials These fluids can change from a thick fluid (similar to motor oil) to nearly a solid substance within the span of a millisecond when exposed to a magnetic or electric field; the effect can be completely reversed just as quickly when the field is removed. • MR Applications • car shocks • damping washing machine vibration • prosthetic limbs, • exercise equipment • surface polishing of machine parts • ER Applications • Viscous clutches • Valves • Reduced noise engine mounts
Phosphorescent pigment Applications such as emergency exit signs, jewellery and toys
Piezoelectric Materials • 2 unique properties • When deformed, they generate a small but measurable electrical current. • When an electrical current is applied, they change size • up to a 4% change in volume • Applications • Sensors • The airbag sensors in cars detect force of impact • Buzzers • Low quality speakers
Smart Springs • Made from any alloy of nickel/titanium • At room temperature the spring is fully extended manually • By heating up or applying a small electric current the spring will return to its original position and carry a load • Possible applications • Emergency shutter in case of fire of: • Bin lids • Blinds • windows
Quantum Tunnelling Composite • Possible Applications: • Pressure sensor • Electronic switches • Weighing machines Pressure sensitive touch screens
Polymorph • Supplied as granules • When heated to 62 degrees or above in water they form a plyable solid • Useful for forming : • handles/grips • Complex shapes • Prototype patterns for casting or moulding • Completing complex assemblies
Smart materials Homework Electroluminescence What is it? (2 marks) What applications are there currently? (2 marks) Design another product that utilises Electroluminescence (6 marks) Have a look at the self healing coating on youtube.