WJEC GCSE Design and Technology Core technical principles: new and emerging technologies, energy, smart materials, electronic systems and mechanical devices

What the core technical principles demand

The core technical principles are the knowledge that every WJEC GCSE Design and Technology learner shares, whatever their route. They make up the bulk of the early questions in the Unit 1 written paper, and they recur in the harder, route-specific questions later in the paper. The core covers the changing technological world, where energy comes from, the newest materials, how electronic products are controlled, and how mechanisms change movement. This guide walks through the core and links to the dot-point page for each part, where worked exam questions live.

New and emerging technologies

New technologies change how products are designed, made and sold. Automation and robotics (CNC machines, robot arms) raise output and repeatability but cut skilled jobs and cost a lot to set up. Enterprise ideas such as crowd funding let designers raise money from many small backers and test demand before manufacture. Design also has wider impacts: it shapes culture and society, can include or exclude groups of people through inclusive design, and carries an environmental cost in the materials and energy it uses. A recurring idea is the difference between a genuine need and a mere want, alongside technology push and market pull as drivers of new products.

Energy generation and storage

Electricity is generated from non-renewable sources (fossil fuels and nuclear) and renewable sources (wind, solar, tidal, hydroelectric, biomass). Fossil fuels are reliable but release carbon dioxide and will run out; nuclear is low-carbon but produces radioactive waste; renewables are clean but often intermittent. Portable products store energy in cells and batteries: cheap non-rechargeable alkaline cells for low use, or rechargeable cells such as lithium-ion for frequent use, chosen for their high energy density so the product stays light. Designers match the power source to the product, from mains to solar to kinetic.

Smart, modern and composite materials

Smart materials respond to their environment and change back: thermochromic (temperature), photochromic (light), shape memory alloy (heat) and piezoelectric (force). Modern materials are new materials made by new processes, such as graphene, kevlar and corn starch polymer (PLA). Composites combine a reinforcement and a matrix for better properties, such as glass-reinforced plastic (GRP) and carbon fibre reinforced polymer (CFRP). These give combinations single materials cannot, such as high strength for low weight, but are usually more expensive and harder to recycle.

Systems approach and electronic systems

A systems approach breaks a product into input, process and output. Inputs are sensors: the switch, LDR (light), thermistor (temperature) and moisture sensor. Outputs produce effects: LEDs, lamps, buzzers and motors. The process block is often a microcontroller, a programmable chip that reads inputs, runs a program and switches outputs. A microcontroller can be reprogrammed, replaces many parts with one, and makes decisions such as timing and counting, which is why it is central to modern electronic products. Designers draw labelled blocks joined by arrows to plan and fault-find a system.

Mechanical devices and motion

There are four types of motion: rotary, linear, reciprocating and oscillating. Mechanisms convert one into another. Levers turn about a pivot and come in three classes; linkages join levers to change direction or type of motion. Gears, pulleys and belts transfer rotary motion and change speed and torque; a small driver turning a large driven gear gives slower, stronger output. Cams and followers turn rotary motion into reciprocating motion. The two key calculations are mechanical advantage, $\frac{\text{load}}{\text{effort}}$, and gear ratio, $\frac{\text{driven teeth}}{\text{driver teeth}}$, where a reduction trades speed for torque.

Check your knowledge

A mix of recall, application and calculation questions covering the core technical principles. Attempt them, then check against the solutions.

1. State one advantage and one disadvantage of automation for a manufacturer. (2 marks)
2. Name two renewable and one non-renewable energy source. (3 marks)
3. Name a smart material and the change it responds to. (2 marks)
4. Name the three blocks of a systems diagram in order. (3 marks)
5. Give a suitable input device for sensing temperature. (1 mark)
6. Name the four types of motion. (4 marks)
7. A driver gear has 12 teeth and the driven gear has 36 teeth. Find the gear ratio. (2 marks)
8. Explain why lithium-ion cells suit portable products. (2 marks)