Basic 9 · Career Technology · Smart and Modern Materials
Smart and Modern Materials
In this topic you will discuss reasons for using smart and modern materials in products and demonstrate techniques for making prototypes that use them to solve environmental problems.
By the end of these notes you should be able to:
- Explain what smart and modern materials are
- Give reasons for using them in products
- Make a prototype that uses a modern material
What you already know
- Resistant and compliant materials
Copy everything that has a blue line on its left into your notebook. The other parts are for reading.
Lesson 1
- Strand
- Materials For Production
- Sub-strand
- Smart and Modern Materials
- Indicator
- B9.2.3.1.1 – Discuss reasons for using smart and modern materials for making products/artefacts
Introduction
Some glasses darken in the sun, and some tiles change colour when they get hot. Materials are changing the way we live.
1. Smart Materials
Smart material: A material that changes in response to its surroundings, and then changes back.
| Material | Responds to | Use |
|---|---|---|
| thermochromic pigment | heat | kettles, thermometers, mugs |
| photochromic lens | light | sunglasses |
| shape-memory alloy | heat | spectacle frames, stents |
| piezoelectric crystal | pressure | gas lighters, sensors |
| hydrogels | water | nappies, wound dressings |
Smart materials respond by themselves, without the need for a person to adjust them. A photochromic lens goes dark in sunlight and clear indoors. Nitinol, a nickel and titanium alloy, can be bent, and it returns to its original shape when warmed.
2. Modern Materials
Modern material: A material developed through new technology for improved properties.
| Material | Properties | Use |
|---|---|---|
| carbon fibre | strong, very light | bicycles, aircraft |
| Kevlar | very tough | protective vests, helmets |
| Lycra | stretches well | sportswear |
| graphene | strong, conducts electricity | electronics research |
| conductive inks | carry electricity | printed circuits |
| bioplastics | made from plants | packaging |
3. Why Use These Materials?
| Reason | Example |
|---|---|
| better performance | carbon fibre in racing bikes |
| safety | Kevlar in protective vests |
| light weight | fuel saved in aircraft |
| energy saving | smart windows that reduce cooling |
| convenience | self-adjusting glasses |
| health | dressings and implants |
| environment | bioplastics that break down |
4. Limitations
Smart and modern materials can be expensive and hard to find in Ghana. They may require special equipment and skills. Some, such as carbon fibre, are hard to recycle. Not all materials marked as "biodegradable" break down easily in the real world. Designers must judge whether the extra benefit justifies the extra cost. Often a simple local material is the best answer. Still, as costs fall, more of these materials will come into use, and Ghanaian workers will need to understand them.
5. Innovation in Ghana
Ghanaian innovators are finding new uses for materials. Nelplast has made paving blocks from waste plastic and sand. Bamboo, though it is not new, is now used for bicycle frames in Ghana, and engineered bamboo can replace some timber. Researchers at KNUST and other universities are exploring local materials for construction, such as bricks made with waste products. These efforts show that modern materials need not be imported: they can also be developed here.
New words
- smart material
- A material that responds to its surroundings.
- thermochromic
- Changing colour with heat.
- photochromic
- Changing colour with light.
- bioplastic
- A plastic made from plant material.
Summary
- Smart materials respond to heat, light or pressure.
- Modern materials are developed for improved properties.
- Their use brings benefits, but they can be costly.
Class activity: Materials Matching
- Write materials and uses on cards.
- Match them.
- Say why each material suits its use.
You need: Reflective fabric strip, Memory-foam sample, Food-packaging film
Exercises
Answer in your exercise book first, then check your answers.
1. Thermochromic materials change with…
- A. heat
- B. sound
- C. wind
- D. salt
Show answer
Answer: heatDefinition.2. Kevlar is used in…
- A. protective vests
- B. bread
- C. ink
- D. soap
Show answer
Answer: protective vestsTough.3. Photochromic lenses react to light.
- A. True
- B. False
Show answer
Answer: TrueSunlight.4. A plastic made from plants is a ______.
Show answer
Answer: bioplasticModern.5. State three reasons for using modern materials.
Show answer
Answer: Better performance, safety and lighter weight.Any three.6. Why might a designer choose a local material over a modern one?
Show answer
Answer: It may be cheaper, easier to obtain and easier to repair.Judgement.
Lesson 2
- Strand
- Materials For Production
- Sub-strand
- Smart and Modern Materials
- Indicator
- B9.2.3.1.2 – Demonstrate techniques for making prototypes/ projects to solve problems in the environment using smart and modern materials
Introduction
Waste plastic is a problem for the environment, but in the hands of a designer it can become a new resource.
1. Identifying a Problem
Start with a clear environmental problem. It might be plastic waste, flooding, poor drainage, dirty drinking water or the need to save electricity. Look for something you can address on a small scale. Plan a solution using available modern materials, such as recycled plastic, thermochromic strips, solar cells, LED lights or strong adhesives. Your aim is to create a prototype that shows that your idea can work.
2. Example Prototype: Solar Phone Charger
- Obtain a small solar panel and a charge controller.
- Connect them with insulated wires.
- Attach them to a stiff, light board.
- Add a USB outlet.
- Test it in sunlight with a phone.
- Record the time taken for charging.
You would be using a modern solar cell to reduce electricity use. An adult should check the wiring before you connect a phone.
3. Example Prototype: Plastic Paving Block
| Stage | Action |
|---|---|
| collect | gather clean waste plastic |
| shred | cut it into small pieces |
| mix | combine it with sand |
| demonstrate | a skilled adult heats and moulds the mixture |
| test | check strength and water resistance |
Safety: Do not melt plastic in class. Melting plastic gives off dangerous fumes. Only trained adults with proper equipment should do this, outside and with protection.
4. Techniques
| Technique | Purpose |
|---|---|
| cutting and folding | quick card models |
| 3D printing | precise plastic models |
| adhesive bonding | joining unlike materials |
| laminating | layering for strength |
| soldering (under supervision) | joining electrical parts |
| recycling | turning waste into stock |
5. Testing and Reporting
Test your prototype against your brief. Does it reduce waste, save energy or solve the problem? How strong is it? What did it cost? Could it be made in larger numbers? Write a report with photos, and be honest about what did not work. Show your prototype to people who could use it, and ask them how it could be improved. Sharing good ideas helps your community to tackle environmental problems.
New words
- prototype
- A first working model.
- adhesive
- A substance that sticks things together.
- laminating
- Bonding layers of material.
- solar cell
- A device that changes light into electricity.
Summary
- Prototypes test solutions to environmental problems.
- Modern materials can be used to create solar and recycled products.
- Always work safely and report honestly.
Class activity: Prototype Design
- Choose an environmental problem.
- Sketch and build a simple model.
- Present it to the class.
You need: Reflective fabric strip, Memory-foam sample, Food-packaging film
Exercises
Answer in your exercise book first, then check your answers.
1. A solar cell changes light into…
- A. electricity
- B. water
- C. plastic
- D. sound
Show answer
Answer: electricitySolar.2. Why should learners not melt plastic in class?
- A. It gives off dangerous fumes
- B. It smells nice
- C. It is illegal to touch
- D. It takes no time
Show answer
Answer: It gives off dangerous fumesSafety.3. Prototypes show that an idea can work.
- A. True
- B. False
Show answer
Answer: TrueTesting.4. A substance that sticks things together is an ______.
Show answer
Answer: adhesiveJoining.5. State three stages in making a solar phone charger.
Show answer
Answer: Get a panel, connect the wires and add a USB outlet.Any three.6. What should you check when testing a prototype?
Show answer
Answer: Whether it solves the problem, how strong it is and what it costs.Evaluation.
Homework
- Write a plan for a prototype that uses waste materials.