Merged flashcards for ESD

polymorph

non-toxic and fully biodegradable polymer, comes in small plastic granules. if heated to 62C the granules fuses to make it moldable, then shaped by hand and is solid when cooled. good for prototyping or making repairs

thermochromic pigments

reacts to heat by changing colour at different temps. used in room and pediatric thermometers, spray paints, childrens cutlery

photochromic pigments

reacts to uv to change color. longer exposed, darker it becomes. caused by reaction of light sensitive particles in pigments. used in nail polish, vehicle spray paint, clothing, beach products

photochromic particles

used in sunglasses (silver halides).

quantum tunneling composite

conductor or insulator. electrical resistance varies on pressure or stress applied. more pressure = conductive particles move closer = less resistance. billions of conductive nanoparticles held in a polymer without touching. no pressure = insulator. used in touch-sensitive pads for phones and computers, keyboards, wearable tech

modern material

materials developed with a specific application in mind. developed by inventing new or improved manufacturing processes

graphene

ultra-thin, transparent layer of graphite just 1 atom thick and 200x stronger than steel. light, strong, flexible, strechable, great conductor of heat & electricity. no developed uses but potential to be used in aerospace, medical, electronic and energy industries

cornstarch polymers

plastics made from vegetable starches, fully biodegradable, non-toxic when composted. used for disposable food and drink containers, bottles, pens

metal foams

metals (e.g. aluminium) that contain many gas-filled spaces which make the material lightweight, while still stiff, tough, and strong under compression. uses are bone implants, lightweight car parts

titanium

extremely corrosion-resistant, high strength-to-weight ratio. pure t. does not react with the body and is used in medical, artificial joints, dental implants, orthopedic applications

fibre optic

optical fibres that allow digital info to travel as pulses of light along thin glass strands at very high speed. carries more info than copper, does not suffer from electromagnetic interference (distorts signal). inner glass core little thicker than human hair, transmits light by reflecting it off the wall of the cladding. used in telephone cables, internet communications & cable tv signals

liquid crystal displays (LCDs)

nanoengineered materials

materials engineered into very small particles or structures on the nano scale (1-100 × 10^-9m). often shows new properties

applications of nanoengineered materials

• sunscreen (nanoparticles absorb UV rays)

• carbon fibre structures (stiffened using silica nanoparticles)

• lithium-ion battery (electrodes based on nanoparticle tech)

• flexible solar cells (uses nanoparticle tech)

• self-cleaning glass (used in construction, uses nanoparticles)

composite materials

made up from two or more different materials bonded together

glass reinforced plastic (grp)

also known as fibreglass, glass fibres coated in thermosetting plastic resin. stronger and tougher than the plastic by it self, heat-resistant, easy to mold into complex shapes. used in boats, kayaks, surfboards, PCBs

carbonfibre reinforced plastic (crp)

carbon fibres coated in thermosetting plastic resin. lighter, tougher, stronger than grp, but more expensive. uses are protective helmets, racing cars, sports equipment, laptops

technical textiles

enhanced fabrics designed to be purely functional

kevlar

synthetic fibre that can be woven into a very strong fabric that is resistant to abrasion (scraping). useful in bulletproof vests, protective clothing for motorcyclists

nomex

fabric of synthetic fibres that have fire resistance built into them instead of the fbaric being treated with flame retardance. (fire-resistance cannot be washed or worn away) used in firefighters’ and racing drivers’ overalls

What is the process of all mechanisms?

Input, Process, Output

What are the types of movement in mechanisms?

Linear, Reciprocating, Rotary, Oscillating

What does a linear mechanism do?

Straight line, one direction

What does a reciprocating mechanism do?

Straight line, forwards and backwards movement

What does a rotary mechanism do?

circular movement

What does a oscillating mechanism do?

circular forwards and backwards movement

What is the three parts of a lever?

Effort load Fulcrum

What is the ‘effort’ part of a lever?

The power you put into a lever

What is the ‘Load‘ part of a lever?

The weight of the object moved

What is the ‘fulcrum‘ part of a lever?

The point at which the lever turns or pivots

What is the first class of a lever system

E F L

What is the second class of a lever system

F L E

What is the third class of a lever system

F E L

The formula of mechanical advantage

MA = Load / Effort

The formula of velocity ratio

VR = distant effort moves / distant load moves

What is the type of linkage that goes back and forth

Reverse motion linkage

What is the type of linkage that turns 90 degrees in direction

Bell crank

What is this cam?

Eccentric cam

What is this cam?

Ratchet/snail cam

What is this cam?

Pear cam

What is a pulley?

A wheel with a groove around its edge in which a belt, rope or chain can sit

What is the formula for Speed Ratio

SR = Diameter of driver pulley / Diameter of driven pulley

What are the two parts of a pully (gears)

Driver pully and Driven Pulley

What is this type of gear?

Bevel gear

What is this type of gear?

Worm gear

What is this type of gear?

Rack and pinion gear

What is a smart material?

one which changes its properties in response to a change in environment, reacting to stimuli

What are smart alloy?

A group of alloys which have super elasticity and have Shape memories

What is a nitinol made of?

an alloy made of nickel and titanium

What is a feature of nitinol?

it is biocompatible and a smart alloy with shape memory characteristics.

What are Shape-memory Plastics (SMPs)?

These can be used to sense temperature change because they change shape when a certain temperature is reached.

What is a polymorph?

What can super elasticity do?

undergoes large strains and spring back to their original shape (normal metal alloys are permanently deformed)

What is a medical application for nitinol?

used in arterial stents to widen restricted arteries. the mesh stent is compressed and placed inside the artery. it is then warmed which expands to its original shape, pushing against the artery walls, allowing improved blood flow

What is a polymorph?

non-toxic and fully biodegradable polymer, comes in small plastic granules. if heated to 62C the granules fuses to make it moldable, then shaped by hand and is solid when cooled. good for prototyping or making repairs