HKDSE Design & Applied Technology Study Notes: Nature of Technology

Hello! Welcome to your study notes for the "Nature of Technology". Don't worry, this isn't just about robots and spaceships. Technology is all around us, from the pen you're holding to the Octopus card in your wallet. In this chapter, we'll explore what technology really is, where it comes from, and the basic building blocks (like energy and materials) that make everything work. Getting these fundamentals right is super important because they are the foundation for all the exciting design projects you'll do later. Let's get started!


1. Innovation and Technology

This is the core idea! We need to understand what technology is and how new ideas are born and improved.

What's the difference between Science and Technology?

This is a classic question, and it's simpler than you think. They are best friends, but they have different jobs.

  • Science is about discovery. It's the process of asking "why?" and "how?" to understand the natural world. For example, a scientist discovers that electricity flowing through a thin wire can make it glow.
  • Technology is about application. It's using scientific knowledge to solve problems and create useful things. For example, an engineer uses that scientific knowledge to invent the light bulb.

Memory Aid: Think Science = Studying the world. Technology = making Tools.

Invention vs. Innovation: What's the big deal?

These two words are often mixed up, but they mean different things. Getting this right will really show you understand the topic.

Invention: This is the creation of a brand new product or process that has never existed before.

  • Example: The very first telephone invented by Alexander Graham Bell. It was a totally new concept.

Innovation: This is the process of making an improvement or a significant contribution to something that already exists. It can make a product better, cheaper, or useful in a new way.

  • Example: The iPhone. The telephone already existed, but Apple innovated by combining it with a camera, an internet browser, and a music player into one easy-to-use device.
  • HK Example: The Octopus card system is a fantastic example of innovation. It didn't invent payment cards or wireless technology, but it innovated by combining them into a super convenient system for transport, shopping, and more.
Case Study: Let's Analyse a Bicycle!

A simple bicycle is a perfect example of technology. Let's break it down like the syllabus wants us to:

  • Energy Conversion, Transmission and Control Systems:
    • Energy Conversion: Your leg muscles push the pedals (kinetic energy), which is converted into the turning motion of the wheels.
    • Transmission: The chain and gears transmit this power from the pedals to the back wheel. Changing gears makes it easier or harder to pedal.
    • Control: The handlebars are used for steering (control of direction), and the brakes are used to slow down (control of speed).
  • Materials Used:
    • Frame: Often made of steel (strong but heavy) or aluminium alloy (lighter but still strong).
    • Tyres: Made of rubber for grip and to absorb shock.
    • Saddle (Seat): Often plastic with foam and a synthetic cover for comfort.
  • Manufacturing Processes:
    • The frame tubes are cut and welded together.
    • Wheels are assembled by attaching spokes to the rim and hub.
    • All the standard parts (gears, brakes, chain, pedals) are then assembled onto the frame.

Quick Review Box

Technology uses science to solve problems.
Invention = Creating something completely new.
Innovation = Improving something that already exists.

Key Takeaway for this Section

Technology isn't just about new things; it's about creatively solving problems. Understanding the difference between a new idea (invention) and a clever improvement (innovation) is key. Even simple objects like a bicycle are packed with different technological systems and smart material choices.


2. Energy and Energy Resources

Nothing works without energy! A designer must think about where the energy for their product comes from and how it can be used efficiently.

Types of Energy Resources

We can group energy sources into two main types:

  • Non-Renewable Resources: These are resources that we use up much faster than they are made. Once they're gone, they're gone for a very long time.
    • Examples: Fossil fuels like coal, oil, and natural gas.
  • Renewable Resources: These resources are naturally replenished or won't run out. They are much better for the environment.
    • Examples: Solar power (from the sun), wind power, and hydro-electric power (from moving water).
Energy in Products: A Designer's Responsibility

When you design a product, you must think about its energy journey. This is super important for creating sustainable and user-friendly products.

  • Sources of Energy: How will your product be powered? Will it plug into the wall? Use batteries? Or maybe even be solar-powered?
  • Energy Conversion & Efficiency: Energy is often changed from one form to another. For example, a hairdryer converts electrical energy into heat and kinetic energy (the fan). Efficiency is how much of the input energy becomes useful output energy. An inefficient product wastes a lot of energy (often as heat). An LED light bulb is much more efficient than an old incandescent bulb because more of the electricity becomes light instead of wasted heat.
  • Consumption, Waste, and Conservation:
    • Consumption: How much energy does the product use? This affects the user's electricity bill and the environmental impact.
    • Waste: Inefficient products create energy waste. Think of a phone charger that gets very hot – that heat is wasted energy!
    • Conservation: How can you design the product to save energy? Examples: Using more efficient components, or adding an 'auto-off' feature.
Did You Know?

That "phantom load" or "vampire power" is the electricity used by devices even when they are turned off but still plugged in? As designers, creating products with a true 'off' switch can help conserve a surprising amount of energy!

Key Takeaway for this Section

Energy is a crucial design consideration. A good designer chooses appropriate energy sources, aims for high efficiency to reduce waste, and thinks about how to help the user conserve energy. This isn't just good for the planet; it's good design!


3. Materials and Standard Components

Ideas are great, but you need physical stuff to build them! Understanding materials is like a chef understanding their ingredients.

Properties of Common Materials

Different materials behave in different ways. We choose a material based on its properties. Here are some key concepts:

  • Stress and Strain:
    • Stress is the force applied to a material over an area (like pressure).
    • Strain is how much the material deforms or stretches under that stress.
    • Think of it like this: If you pull on a rubber band, the pulling is the stress, and the amount it stretches is the strain.

Here are the main material families you need to know:

  1. Plastics: Lightweight, good insulators, can be easily moulded into complex shapes. Examples: PET for drink bottles, PVC for pipes.
  2. Wood: Strong for its weight, natural aesthetic, renewable, but can be affected by moisture. Examples: Pine for simple furniture, teak for outdoor furniture.
  3. Metals: Strong, ductile (can be drawn into wires), good conductors of heat and electricity. Examples: Steel for construction, aluminium for drink cans, copper for electrical wires.
  4. Ceramics: Very hard, good insulators, can withstand high temperatures, but are brittle (can shatter easily). Examples: Clay for pottery, silica for glass.
Standard Components: The LEGOs of Engineering

Imagine if you had to design and make every single screw for a project. It would take forever! That's why we use standard components.

  • What are they? They are pre-manufactured, commonly used parts that are made to a specific standard size and specification.
  • Examples: Nuts, bolts, screws, bearings, switches, and resistors.
  • Why use them?
    • Cost: They are mass-produced, so they are cheap.
    • Reliability: They are made to a consistent quality.
    • Availability: They are easy to find and replace.
    • Efficiency: It saves designers a huge amount of time.
Case Study: The Humble Beverage Container

Let's look at a drink can or bottle, keeping the syllabus points in mind:

  • Raw Material: An aluminium can uses bauxite ore. A plastic bottle uses petroleum (crude oil).
  • Process: The aluminium is rolled into a thin sheet, then punched and drawn into the can shape. Plastic bottles are made by blow moulding.
  • Market Form: The cylindrical shape is strong, easy to hold, and stacks efficiently for transport and on store shelves.
  • Recycling: Aluminium is highly recyclable and saves over 90% of the energy compared to making a new can. Plastic can also be recycled. This is a huge issue in design!
  • Optimising Resource Exploitation & Government Policy: Designers try to use less material ('light-weighting') to save cost and resources. Governments often promote recycling through policies like waste-charging schemes or providing recycling bins everywhere.
Common Mistake to Avoid

Don't just say "the frame is made of metal." Be more specific! Is it steel or aluminium? Why was that metal chosen? Always try to link the material choice to its properties and the product's function. For example, "An aluminium alloy was chosen for the bicycle frame because it provides good strength while being lightweight, making the bike easier to ride."

Key Takeaway for this Section

The materials you choose define what your product can do. A good designer understands the properties of different materials and uses standard components cleverly to make their products affordable, reliable, and efficient to produce. Thinking about the entire life-cycle of a material, including recycling, is a vital part of modern design.