GCSE Edexcel DT: Core Content

Impacts of tech on industrial processes

Advantages:

- More efficient ∴ cutting costs

- Quicker manufacture ∴ brought to market quicker

- Easier analysis & manipulation of information in stock

- Decrease in human error

- Increased safety as robots take dangerous jobs

- Employees are acquiring new skills (improving workforce skills set), embracing tech to compete in the labour market

- Demographic movement with people towards jobs with new or specialist tech

Disadvantages:

- Unemployment as robotics takes low-skill jobs

- Demographic movement with people moving away from low-tech areas/countries

Effect of science & tech parks on new and emerging tech

They enable businesses to associate with universities or research organisations allowing for transfer of knowledge & technology-led economic development in the surrounding area (e.g., Silicon Valley)

Disadvantages of these parks are that they can infringe on greenfield sites resulting in habitat loss and resentment among locals

Definition of an enterprise and the types

A business, particularly one started by someone who shows initiative by taking a risk setting up, investing in and running it

Types: Privately owned businesses, crowd funded projects, government funded projects, not-for-profit organisations

Privately owned businesses

Privately owned businesses tend to be relatively small with limited sales, stock and workforce. Strategic decisions are made by the owner(s). An advantage is that they are often sufficiently flexible to easily adopt, adapt and exploit new technologies. However, they may not have enough funds to invest in cutting-edge manufacturing equipment.

Crowd funding

Crowd funding is a comparatively new way of launching new products or technologies. It funds a project by raising money from a large number of people who each contribute a small amount of money online. It depends on capturing the imagination of potential funders, using online platforms to coordinate and administer the funds.

Government funding

Government funding is often available for new businesses that could contribute to the overall economy, making the use of new and emerging technologies easier for them. Local councils may also provide lower-level loans or grants.

Not-for-profit organisations

Not-for-profit organisations reinvest the money they make into their cause (e.g., healthcare phone apps)

Effect of tech on the consumer

- Consumers want newer technology increasing use of scarce resources need to make them

- Education & entertainment for children

- Allows for assistive tech for those with disabilities: all-terrain wheelchairs, prosthetics, eye tracking, screen reader, voice recognition

- Creates training opportunities for apprentices, with online progress logging and apprentices testing out new products

Effect of tech on the worker

- Companies attract wider skill bases in their workforce as tech takes lower skilled jobs and people are needed to operate new technology in manufacturing by increasing wages for those jobs in demand. Workers try to develop new skills to stay in demand throughout their careers

- Changes in working hours and shifts due to internet and mobile apps allowing workers to access systems whenever convenient, increasing labour available, productivity & morale

- Tech allows for remote working as employees can access employer's services using remote devices as well as video conference meetings

- IoT (Internet of Things): interrelated devices connected to the internet allowing for tracking & controlling inventory, security, factory management, and energy conservation. Concerns: malfunction, over-reliance, data breaches

Advantages of remote working

- Flexible work schedule (work at own pace)

- Less time & money wasted commuting

- Fewer distractions

Disadvantages of remote working

- Lack of routine

- Less social interaction

- Blurs work-life balance

- Less IT support would affect productivity

- Data breaches

Advantages of video conferencing

- Meetings and training can take place without leaving the office

- Travel costs and the time taken to travel can be reduced or eliminated

- Meetings can be called instantly at multiple locations with little notice

- Speeds up decision making and problem solving

Disadvantages of video conferencing

- May not be as productive as a discussion around a table

- Confidential documents may need to be viewed and signed in person

- May be a high set-up cost

- May be difficult to find a suitable time across time zones

- People may not pick up on non-verbal information such as body language

Culture & Technology

- Labour movement within the EU allows for immigrants bringing innovation, skills & experience of tech

- Social segregation where minorities live in clusters results in social barriers, limiting access to education, jobs and technology

Effect of tech on transportation

- Changing fuels (diesel → electric)

- Making fewer journeys by having distribution centres close to destinations

- Designing lighter & smaller products fitting more in one shipment

- Packaging is swapped for biodegradable/recyclable materials (increases price of product)

Effect of tech on pollution

- Government has carbon taxes or subsidies for alt. energy sources

- Software predicts environmental impacts

- Old polluting tech is replaced

- Tech has improved efficiency of extraction of natural resources and has allowed for new sustainable materials

Effect of tech on waste

- Reducing: computer-control minimises off-cuts and rejects & improves efficiency

- Reusing: waste used in a later stage of manufacture

- Recycling: Automated machines separate materials by type (processed to no impurities) so they can be recycled ⇒ fewer raw materials sent to landfill. E.g., plastics can be melted and reset with no degradation of quality

- Recovering waste: recovering heat via CHP

Standardised design and components description

Same components or modular systems are used across many designs in large numbers manufactured to an internationally accepted standard

(e.g., resistors, nuts & bolts)

Standardised design and components advantages

Consistent safety & quality

Speeds up product development: parts already exist and workforce is trained to deal with those parts

Cheap

Standardised design and components disadvantages

Difficult to customise

Quality of product may suffer

Just in time (JIT) description

Computerised stock control ensures that parts are only received when needed (on demand) → no storage required

Just in time (JIT) advantages

Increase efficiency, reduce waste

Changing to production runs can meet demands

Just in time (JIT) disadvantages

Any break in the supply chain holds up production

Cost of more frequent deliveries

Fewer bulk-buying discounts

Lean manufacturing description

Reducing or eliminating waste in design, manufacturing, distribution, customer services

Lean manufacturing advantages

Higher efficiency when using multi-skilled teams working together to share skill & expertise for each part of the production process

Lean manufacturing disadvantages

Requires time-consuming data analysis

Requires disruptive changes to existing processes

One-off scale description

One product made at a time, either for a specialist product, or to test an idea

One-off scale advantages

- No set-up cost

- Made with existing equipment

- Product can be customised to user's needs

One-off scale disadvantages

Slow, so expensive to make several

Batch scale description

Several copies of the same product are made at the same time

Batch scale advantages

- Jigs, templates and moulds speed up the process and can be kept for future use

- Special machinery is not needed, so set-up cost is not high

- Low cost, identical products, easily changed

Mass scale description

Factory machinery set up to make lots of identical products

Batch scale disadvantages

- Labour intensive, so it is quite expensive per product

- Takes time to make jigs, moulds and templates

- Poor planning can result in waste products

Mass scale disadvantages

Machinery expensive to set up, so only worthwhile for making a lot of products

Mass scale advantages

- Can make a product quickly and cheaply

- Automatic process, very efficient, low unit costs, lower labour costs

Continuous scale description

Factory machinery making the same thing 24/7

Continuous scale disadvantages

Machinery expensive to set up, so only worthwhile for making huge quantities of a products

Continuous scale advantages

Makes the product very quickly and cheaply

Advantages of a template in batch production

- Speed up the process

- Minimise waste to mark out shapes as close together as possible

Solar

Photovoltaic panels: sunlight → electricity using 2 layers of doped silicon to allow electrons to flow when photons fall on them

Solar thermal: sunlight → heat fluid circulated through pipes → transfers heat to water → steam → turbine → generator → electricity

Advantages:

- Renewable, and no pollution

- Useful for low-power

- Useful in remote areas

- Solar thermal reliable in warmer countries

Disadvantages:

- Take up lots of space

- Inconsistent (energy must be stored)

- Expensive set up

- Low efficiency - depends on location

- Unaesthetically pleasing

- Could change ecology when large solar farms replace traditional farms

Hydroelectric

Flowing water due to gravitational potential energy turns a turbine and generator as it descends the dam

Advantages:

- Consistent

- Can be used for pumped storage

- Can increase to full power quickly and turn off quickly

- Cheap to run

- Can have secondary function as water reserve

Disadvantages:

- Can cause floods and trap wildlife

- Very expensive to build

- Hard to find suitable site

- Water quality + quantity downstream can be affected

Pump storage

Upper reservoir's water can be quickly released and due to GPE, it will turn a generator. When demand is low, lower reservoir's water can be pumped back up to store the energy

Advantages:

- No emissions/fuel

- Very quick

- Very useful to cope with spikes in demand

Disadvantages:

- Expensive to build

- Environmental issues regarding building of dams

Wind

Thermal energy from convection currents → kinetic energy in wind → spins propeller blades → turn a shaft → turbine + generator to produce electrical energy

Advantages:

- Freely available

- Renewable, and no emissions

- Land beneath is still usable

- Useful for remote areas

Disadvantages:

- Not consistent

- Few suitable coastal areas

- Could restrict shipping traffic when placed in the sea

- Kill wildlife & disturb migration patterns of birds

- Wind farms = unsightly

Geothermal

Water heated underground when in contact with hot rocks and the earth creates steam that drives turbines to generate electricity. (Heat retained in the earth created by radioactive rocks & solar radiation absorbed at the surface)

Advantages:

- Renewable, and no emissions

- By-products are often minerals which can be sold or are re-injected

Disadvantages:

- Not many suitable locations

- The area may run out of steam

- Hazardous substances may come up from underground which are hard to safely dispose of

Tidal

Turbines within barrages (dams) constructed across tidal rivers, bays, and river estuaries can use rising and falling tides to generate electricity. Water is trapped and then released through the turbines as water levels change

Advantages:

- Renewable, and no emissions

- Cheap to maintain and operate

- Can produce lots of energy

- Is very predictable & stable (so you can plan)

- Barrages can serve a secondary function like a bridge

Disadvantages:

- Very few suitable sites (coastal areas only)

- Only works for 10 hrs tide flows ∴ lower energy output than fossil fuels

- Very expensive to build

- Environmental impacts for fish, birds

Biomass

Organic matter derived from wood, crops, rubbish, landfill gas, alcohol fuels etc. burnt to produce heat (which can then be converted to electricity)

Advantages:

- Renewable waste reduction (e.g., from farming)

- Reliability

- Availability

Disadvantages:

- Not completely clean (combustion still causes emissions)

- Possible deforestation

- High cost & space requirements

- Requires lots of water

Biodiesel

Made from plants/vegetables/fermented waste/cooking oil and can be used in diesel-powered vehicles without modifying engine

Advantages:

- Renewable waste reduction (e.g., from farming)

- Reliability

- Availability

Disadvantages:

- Possible deforestation

- High cost & space requirements

- Requires lots of water

Coal

Burn → heat converts water into steam → turns turbine → generator → electricity

Smaller amounts used as domestic heat source

Advantages:

- Stable, large-scale, and high-power electricity generation

- Cheap to extract & use

- Reliable

Disadvantages:

- Emit CO₂, particulates, NOₓ, SOₓ, Sulfur, Mercury, Selenium, Arsenic (is the dirtiest fossil fuel)

- Technologies to reduce coal power plant emissions are expensive

- Coal mining impacts landscape & produces toxic dust

Oil

Crude oil processed & split into petroleum products: petrol, paraffin and diesel

Burn → heat converts water into steam → turns turbine → generator → electricity

Advantages:

- Stable, large-scale and high-power electricity generation

- Cheap to extract & use

Disadvantages:

- Oil power plants are highly polluting

- Oil exploration impacts on the landscape

- Oil extraction risks environmental disasters (fracking)

Gas

Burn → heat converts water into steam → turns turbine → generator → electricity

Natural gas used in homes for heating or cooking

Advantages:

- Stable, large-scale and high-power electricity generation

- Cheap to extract & use

- Cleaner than coal or oil (emits half the CO₂ as coal)

Nuclear

²³⁵U used in fission to heat water to steam turning turbines → electricity

Advantages:

- No air pollution, therefore fewer health impacts

- High energy density

- Safe

- Very low fuel cost

- Useful for the base load of the UK

Disadvantages:

- Non-renewable

- Affects marine life as cooling water systems used to maintain temperature are taken from a river or ocean. Fish and other organisms are unintentionally captured in the cooling system are killed. After the water is used to cool the power plant, it is returned to the ocean/river, but the water returned is 25° warmer than it was originally.

- Long start-up time

- Safety measures are expensive

- Accidents would be catastrophic (although new tech using thorium reduces this)

- Radioactive waste, so disposal is difficult, and leaks are hazardous (although thorium reduces this)

- Some say it causes nuclear proliferation (although thorium as fuel makes it harder to make nuclear weapons)

How a company can reduce carbon footprint

- maximising energy efficiency

- analysing their supply chain

- recycling

- using renewables

- identifying suitable carbon offsetting methods

LCA:

- raw material extraction & processing

- product/part manufacture & assembly

- product/part transportation & distribution

- product use

- product disposal/recovery

Power system

a network of components that supply, transfer and use electric power, including batteries and cells, wind, solar, and mains electricity

Things to consider when selecting power systems for products

portability of power source, environmental impact (including creation, transport, and disposal), power output & consistency, circuit/system connections, cost

Mains electricity supply

AC 50Hz 230V

Description & disadvantages of batteries and cells in general

Chemical reaction produces electrons that collect at the negative terminal and when connected in a circuit flow to the positive terminal

Expensive source of electricity

Can lead to chemicals leaching into water & soil if not disposed of correctly

Advantages of cylindrical cells (D, C, AA, AAA, AAAA)

- Easy to manufacture

- Small

- Inexpensive

- Have good mechanical stability and long life

Advantages/disadvantages of prismatic cells (ones used in mobile phones + tablets)

Advantages:

Prismatic cells are flexible, easy to recharge

Disadvantages:

Prismatic cells are expensive, have a shorter life than cylindrical batteries

Examples of smart materials

SMAs, Nanomaterials, Photochromic glass, reactive glass, piezoelectric materials, temperature responsive polymers, conductive inks

Nanomaterials (carbon nanotubes) description & application

Particles, nanowires nanotubes, or thin films and surface coatings

Fire retardants, Sunscreen, Tennis rackets, Helmets, Car bumpers

Nanomaterials (carbon nanotubes) advantages

Higher surface area ∴ higher strength, elasticity, conductivity, absorbance

Can combine properties

Nanomaterials (carbon nanotubes) disadvantages

Unusual physical and chemical properties ∴ risk assessment needed for health + safety

Shape-memory alloys (Nitinol, Gold-cadmium) description & application

Can be plastically deformed but will return to shape when heated/current applied

Glasses frames, stents, tweezers and hooks, orthodontic wires

Shape-memory alloys (Nitinol, Gold-cadmium) advantages

Lengthen life of product

Decrease size + complexity

Shape-memory alloys (Nitinol, Gold-cadmium) disadvantages

Expensive

Continuous use ⇒ metal fatigue

Photochromic glass description & application

Darkens when ↑ light (UV reaction with silver halides)

Sunglasses, plane cockpit windows

Photochromic glass advantages

Adapts easily

No fatigue/ performance change

Photochromic glass disadvantages

May be slow

User cannot control reaction

Reactive glass description & application

Use electro chromatics to change transparent → opaque when current applied

Welding masks & Windows

Reactive glass advantages

Retains heat

Instant privacy without permanent blocking of light

Reactive glass disadvantages

Expensive

Requires electricity source

Piezoelectric materials (Quartz, Topaz) description & application

Generate small charge when compressed/Generate movement when electric charge applied

Generating energy, Sensors (burglar alarms, sear belt etc.), Actuators for precise position control (cameras), Piezoelectric transducer

Piezoelectric materials (Quartz, Topaz) advantages

Sustainable

Low maintenance

Compact

Actuators have high response speed and high force

Piezoelectric materials (Quartz, Topaz) disadvantages

Wears out

Has temperature and voltage limits

Temperature responsive polymers (PNIPAM) description & application

Can change with temperature

Can deliver drugs, cells, proteins to patients and release when temperature rises

Temperature responsive polymers (PNIPAM) advantages

Useful in biomedicine

Temperature responsive polymers (PNIPAM) disadvantages

Still in research

Conductive Ink (silver, carbon, graphite base) description & application

Contain conductive pigments (even when dry)

Drawing working circuits on polyester, polycarbonates, paper, Repairing PCBs, Print ticket RFID tags

Conductive Ink (silver, carbon, graphite base) advantages

Easy to use

Light and economical

Low waste

Ink can be folded

Examples of composites

Concrete

Plywood

Fibre/carbon/glass

Reinforced polymers

Robotic materials

Conductive Ink (silver, carbon, graphite base) disadvantages

Silver is expensive

Difficult to get working

Concrete description

Made of coarse aggregate (gravel between 14 and 40 mm); aggregate (sand); cement; water

Proportions depend on the use

Hardens over time to gain excellent compressive strength, but tensile strength is low

Relatively cheap

Can last 100 years. Additives can prevent attack from seawater or acids

Tensile strength can be improved by embedding steel rods to form reinforced concrete

Concrete examples

Mainly used for construction but it can be used for smaller products such as park benches and bins

Concrete advantages

Excellent compressive strength

Good heat and sound insulator

Can be moulded into complex shapes with a variety of surface finishes, so has many applications

Can be manufactured on site, so reduces transport issues

Durable, fire-resistant

Will last for a long time

Concrete disadvantages

Can be damaged by corrosion of reinforcement bars, fire or radiant heat and freezing trapped water

Plywood description

Manufactured board of wood veneers bonded with glue to produce a flat sheetAlways has an odd number of layers (at least three) as they balance the stresses around the central core, making it stable in all directions The veneers' grain direction runs at 900 to the sheets above and below it, which also increases the stability

Plywood examples

Graded for exterior or interior use depending upon the glue's water resistanceSheds, cladding, flooring, furniture

Plywood advantages

High strength-to-weight ratio and strong in all directions

High impact resistance, so not easily damaged

Versatile - can be used inside and outside

Economical use of wood as less wastage and available in large sheets

Plywood disadvantages

Although plywood is strong and stable, some plywood will come apart if the layers become wet

Fibre/carbon/glass description

Plastic can be reinforced with fine glass or carbon fibres to make a higher strength-to weight ratio than its component partsLoose or woven fibres form a flexible fabric, and are built up in layers with polyester resinReinforced plastic can be sanded for a smooth finish and painted or colour added at the start of the process

Fibre/carbon/glass examples

Glass reinforced plastic (GRP) is easily formed into shapes - it is best suited to large structural items, such as boat hulls, pond liners, car bodies, baths or showersCarbon fibre reinforced plastic (CFRP) is more expensive than glass fibre but is much stronger - it is used in structural parts such as propeller blades, body armour and golf clubs

Fibre/carbon/glass advantages

Low maintenance, durable and good resistance to ultraviolet (UV) light and most chemicals

Able to be formed into most 3D shapes, with added surface texture

Lightweight with an excellent strength-to-weight ratio

Fibre/carbon/glass disadvantages

Breathing in the fibres can cause respiratory problems

Reinforced polymers description

Phenolic resins are combined with cotton fabrics to make inflammable laminated plastic sheets, rods and tubesGrades depend on fibre coarseness -- all are about half the weight of aluminium, strong, tough and with insulating properties at high temperatures

Reinforced polymers examples

Non-metallic engineering components like gears and bearingsSubstitute for exterior timber because they are weatherproof and do not need further treatment

Reinforced polymers advantages

Strong with good wear resistance and excellent machining qualities (will not blunt too as much as metals)

Good insulator of heat and electricity with low water absorption

Available in a range of forms

Good dimensional stability (does not change shape in heat or moisture-rich environments)

Reinforced polymers disadvantages

Can be expensive

Robotic materials description

Materials that couple sensing, activation (movement), computation and communication and can react to their surroundings autonomously,

Robotic materials examples

Vehicles or uniforms that change colour to match their surroundings

Prosthetics with a sense of touch

Plane wings that change shape depending on wind conditions