Lesson video

Hello there.

My name is Mrs. Dhami.

Thank you for joining me for your design and technology lesson today.

Now, the big question for today is, what are modern materials?

Now, hopefully, I'm going to absolutely wow you with some amazing examples today.

It's really, really exciting.

But another exciting part is if these things have already been invented now, imagine what could be invented in the future.

The design possibilities are endless, and you can be a part of that.

So hard hats on.

Let's get cracking.

The outcome from today's lesson is that we will be able to describe the properties and uses of modern materials and give specific examples.

Our keywords for today are "modern material," "working property," "physical property," and "composites.

" I won't explain each of them now, as I will explain them throughout our lesson as we meet each term.

We have two learning cycles for our lesson today.

First of all, we will explore modern materials, and secondly, we will explore composites.

So let's get started with exploring modern materials.

My question to you is, what do all these people in the three pictures below have in common?

Have a little think, perhaps tell me, perhaps tell the person next to you.

Come back to me when you've got an answer.

Okay, thank you for having a think.

So, Lucas, first of all, said, "They need protective clothing," and he's absolutely right.

Laura said, "They are likely to experience high temperatures," and I wonder if some of you got that answer too.

They therefore require a modern material fit for the job.

And later on in this lesson, we will come back to those three people and have a little look at what that modern material is.

Modern materials are those that are continually being developed through the invention of new or improved processes.

Modern materials are designed to overcome the limitations of traditional materials by offering enhanced properties that help solve specific problems.

Now, those properties could be working properties.

Let's remind ourselves of what those are because this is one of our keywords for today.

Working properties are the way in which a material responds to an external force or certain environment, also referred to as mechanical properties.

Now, a really good example of this is impact resistance.

Physical properties could also be enhanced.

Now, these, again, let's remind ourselves, this is, again, one of our keywords, physical properties are the characteristics of a material, such as appearance and features.

So the aesthetics, the way that a product looks.

Quick check-in then.

What defines modern materials?

A, have been used for centuries without change.

B, are only made from natural resources.

C, cannot be altered or improved.

D, continually developed through new or improved processes.

Have a little think.

Come back to me when you've got an answer.

Okay, hopefully, you managed to work out it was D.

Modern materials are continually being developed through new or improved processes.

Well done if you got that right.

Nomex is our first modern material that we're going to look at today.

Now, the working properties of Nomex are that it is heat and flame-resistant.

Bet that's got your mind ticking back to that first slide.

And if it does, then you're absolutely right because our example today is protective clothing, such as astronauts, firefighters, and racing drivers.

They all need protective clothing that, if they come into contact with really high temperatures or flames, it is going to protect them.

Let's take a little closer look at how that works.

Nomex has a honeycomb structure, and you can see that on our picture in the right.

Honeycomb structure forms strong, stable bonds that do not easily break down in heat.

What a fantastic material.

And next modern material is Teflon.

Now, I think you might have heard this word before.

So have a little think.

It might be closer than you think, too.

Come back to me when you've had that time.

Okay, hopefully, you might have thought about that with your school uniform.

Now, quite often when you buy a new pair of school trousers or a new skirt, quite often you see this little symbol saying Teflon.

So let's look in a bit more detail.

The working property of Teflon is that it repels liquids.

So if it rains a bit of rain, your trousers don't get completely soaked.

So our examples are school trousers, but also non-stick frying pans.

And I'm sure you might have a few of these at home, too.

It's great because it repels liquids, and it means that food doesn't get stuck to the pan.

So we look at that in a bit more detail.

You can see I've put my son's trousers under the water there, under the tap, and the water is just rolling straight off.

It is repelling that water.

Obviously, if I immersed it in the water and kept it in there, it's going to get wet.

That's how it is washed.

But it repels kind of that surface water to it.

Onto microencapsulation.

So the working properties of microencapsulation is the ability to release tiny bubbles of liquid or substances with wear.

So our examples include antiseptic medical fabrics, allergy control fabrics such as bedding to prevent dust mites, and sanitized fabrics with antimicrobial properties for socks and sportswear.

Now let's look at that a little bit more closely.

Basically, they have tiny, tiny bubbles of liquids or solids inside of them that are slowly released when worn.

Quite fantastic.

Time for a quick check.

Which product is an example of the modern material Teflon?

We have: A, astronaut clothing; B, school trousers; and C, sanitized fabric socks.

Have a little think.

Come back to me when you've got an answer.

Right, hopefully, you managed to get B, and well done if you did.

School trousers do tend to be made out of the modern material Teflon.

Many modern materials use a weave.

Now, you are likely to have come across the term "weave" throughout your design and technology education.

So let's revisit one.

If you could describe a weave in a sentence, what would you say?

Come back to me when you've got an answer.

Okay, hopefully, you've remembered that a weave looks a little bit like this.

So let's explain.

It has vertical warp yarns and horizontal weft yarns, and you can see those labeled on my diagram.

They produce a woven fabric, interlacing patterns that determine the fabric's texture, strength, and flexibility.

Now, this is important because, as I said at the start of this slide, many modern materials use a weave.

So let's have a little look at some that do.

Kevlar is our first material that uses a weave.

So the working properties of Kevlar are that it is lightweight and has high impact strength.

Now, our examples include bulletproof vests and cut-resistant gloves.

You might not have come across cut-resistant gloves before.

These are what people tend to wear if they're using things like chainsaws to protect their hands, should a bad accident happen.

Now, let's look at this in a bit more detail.

We know that bulletproof vests are important because bullets move at high speed.

The reason Kevlar is made with a weave is because the weave manages to take the impact of the bullet to protect the person wearing it.

What a fantastic material.

Our next one, I hope you recognize it, is PLA, standing for polylactic acid, a biodegradable thermopolymer.

Now, the working properties of PLA are that it has a very low melting point.

Now, why have you heard that material before?

Have a little think.

Come back to me when you have thought of a use of PLA.

Okay, hopefully some of you might have come across PLA with 3D printers.

If you haven't, don't worry.

But it is a new thermopolymer that is used within 3D printers, and it's great because it's biodegradable, especially in comparison to lots of the polymers that we used to use in 3D printers.

You can also find it in compostable bags, such as the one there, and also in disposable cups.

Now, let's take a little look a bit more closely.

PLA is actually made from cornstarch or sugarcane.

Now, if you're sat there thinking, "What on earth is cornstarch?

" Well, it looks like a flour.

It's that top picture there.

Looks like a flour.

And what you do is you add it to say a stew or to a gravy that is a bit too thin, and you want to thicken it up.

So it gives it that thicker texture.

Isn't it amazing to think that a polymer is made by something like cornstarch or sugarcane?

Wow!

How could a material help you to swim faster?

Well, sometimes inspiration comes from nature.

And as you might have heard before, this is also known as biomimicry.

When we take inspiration from nature to make products or materials for humans to make improved properties and improved products, this might have sparked up a few ideas to you.

If it has, pause the video, have a little chat amongst yourselves.

I wonder if any of you guessed Fastskin.

Now, for those of you who have never heard about Fastskin, basically, it mimics the skin of a shark, giving a streamlining effect underwater and reducing drag, which is basically the resistance under the water.

Now, the working properties are that it reduces drag, but it's also lightweight, and that is used in competitive swimwear.

And you can see in the second picture there a bit of a zoom-in to the Fastskin fabric.

Now, if we zoom in a little bit further, basically, it is made up of knitted fibers, which mimic the shark skin, which reduces the drag and allows people to swim a lot faster.

There have been lots of regulations put on competitive swimmers, but you will find that lots of competitive swimmers now do wear Fastskin.

Time for a check.

Fastskin mimics the skin of a shark, giving a "something" effect underwater and reduces "something.

" Is it: A, aerodynamic; B, friction; C, streamlining; D, drag?

Have a little think.

You've got two that you need to choose from, and which position they go.

Come back to me when you've got an answer.

So Fastskin mimics the skin of a shark, giving a streamlining effect underwater and reduces drag.

Well done if you've got both of those right.

Task A.

I would like you to match the modern material to the example product.

So we have Nomex, Teflon, microencapsulation, Kevlar, Fastskin, and PLA.

The example products: we have competitive swimwear, non-stick saucepans, antiseptic medical fabrics, bulletproof jackets, firefighters' clothing, and biodegradable shopping bags.

Have a little think, fill it into your chart.

Come back to me when you've got an answer.

Let's take a look at our answers.

So, for competitive swimwear, hopefully you got Fastskin.

For the non-stick saucepan, Teflon.

For the antiseptic medical fabrics, microencapsulation.

For bulletproof jackets, Kevlar.

For firefighters' clothing, Nomex.

And for biodegradable shopping bags, PLA.

Well done if you got those right.

Modern materials are increasingly used in the design and manufacture of innovative products.

So for part two, I would like you to define the term "modern material.

" For part three, modern materials make use of a weave.

Think back to that diagram that I showed you.

Describe the construction of a woven fabric.

And then for part four, I'd like you to discuss how the development of modern materials has influenced the design of everyday products.

I'd like you to use an example to support your answer and explain the positive impact of the material, and then explain how the material achieves the desired effect.

Good luck.

Come back to me when you've got some great answers.

Let's take a look at our answers.

So, for part two, I wanted you to define what a modern material was or is.

So modern materials are continually being developed through the invention of new or improved processes.

These often help to solve problems that other materials cannot solve.

Part three, I asked you to describe a weave.

So vertical warp yarns and horizontal weft yarns go over and under each other.

And then for part four, you may have picked one of the others.

I chose to pick Nomex.

So Nomex is a modern material used in firefighters' clothing to protect against extreme temperatures and fires.

The honeycomb structure of Nomex forms strong, stable bonds that do not easily break down in heat.

So I thought of one, I described it, I gave an example, and then I said how that works.

Well done with all of your efforts.

Onto our second learning cycle, we are going to start exploring composites.

Many composites are also examples of modern materials.

Composite materials combine the properties of two or more materials without being mixed at a chemical level.

This improves the working and/or physical properties of the material.

Frequently, composites improve the strength of a material or make them more lightweight.

What defines a composite?

A, made from a single material that is chemically altered.

B, created by chemically bonding two materials together.

C, combine the properties of two or more materials without mixing at a chemical level.

Or D, have no distinct properties and act as a single material.

Have a little think.

Come back to me when you've got an answer.

Okay, well done if you've got C.

Composites combine the properties of two or more materials without mixing at a chemical level.

Well done.

A negative to modern materials and to composites are that they are usually more expensive.

However, there is one exception, and that is wood laminates, as they use less expensive manufactured timbers internally.

And I've got two examples to show you here.

So these are some laminate shelves that I have, and they have got chipboard inside with a timber veneer on the outside, making them look like oak, but at a much cheaper price.

Second picture is my desk at my school.

It is a laminate desk.

It's got MDF underneath it as the internal, and then it's got a polymer veneer.

And you can see it's starting to wear away a little bit there, but it is a cheap alternative to having a solid wood on top.

Glass-reinforced plastic, otherwise known as GRP, are glass fiber strands set in resin.

Now, the working properties, it means they have all the properties of a polymer, but with a higher strength-to-weight ratio, and they can be found.

.

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So GRP can be found in blind poles, roofs, and boats.

And basically, if we look at it a bit more closely, it's lots of little glass fiber strands in resin.

And I'm gonna show you that in a bit more detail on my next slide.

Izzy says, "Why does GRP have such good strength-to-weight ratio?

" Great question there, Izzy.

Basically, all the glass fibers fall in different directions, which gives strength in many directions rather than one.

And this is because the glass fibers are set in those positions because they are set in resin.

Let me demonstrate with spaghetti.

If I grab a packet of spaghetti and put it into my dish like that, you can see all of those pieces of spaghetti are going in one direction.

So it's only got strength in one direction, which means it's got little strength.

Now watch this.

I then go on to break up the pieces of spaghetti, put them in a jug, and pour it in.

There was no chance that I was going to get all of those strands of spaghetti facing the same direction.

I could, if maybe I spent hours sitting there, turn each one to face the right direction.

But I'm not gonna do that.

Okay?

Therefore, when all of the fibers are set in many different directions, because they're set because of the resin, therefore, the material has strength in many, many directions rather than in one, like the first image.

Now, I reckon a few of you might know this one.

Carbon fiber reinforced polymer, otherwise known as CFRP, but more commonly referred to as just carbon fiber.

Now, the working properties of carbon fiber is the high strength-to-weight ratio due to the weave.

.

.

There's that word again.

The weave of carbon fibers set in resin.

Remember, resin is the polymer.

So examples include helmets, high-end bikes, car parts, and sporting equipment.

And if we take a little closer look, we can clearly see at the bottom, the weave of carbon fibers.

You can identify the warp and the weft, making that weave go in and out of each other.

Now, the picture above, that's a zoom-in of real carbon fiber.

Laminates are made up of layers; when the layers are different materials, they are called composites.

Now, physical properties, they often give an attractive appearance, often at an affordable price, such as the shelving and my desk that I showed you in a previous slide.

However, they can also provide fantastic working properties, and they can be found in textiles, too.

So working properties such as durability and water resistance are found in products such as waterproof jackets.

And if we take a little closer look at the layers in a waterproof jacket, you can see that the water stays out, but it also allows the sweat to escape due to the layering of the different fabrics.

Which modern material, including composites, commonly use a weave?

We've got A, carbon fiber; B, glass-reinforced plastic; C, Fastskin; and D, Kevlar.

Have a little think.

Come back to me when you've got an answer.

Okay, well done if you got A and D.

Carbon fiber and Kevlar both use a weave.

As I said at the start, modern materials, including composites, provide exciting opportunities for designers and users, but come with both advantages and disadvantages.

Let's explore some of the common ones.

So advantages often include high strength-to-weight ratio, such as the carbon fiber bikes; often resistance to corrosion and environmental damage, think of the roofs; and then customizable properties for specific applications.

However, some of the disadvantages include: they're often expensive to produce.

They're also often difficult to recycle due to the mixing or layering within composites of the materials.

And they often require specialized manufacturing techniques to be able to produce them.

Composite materials are used in many everyday products.

So first of all, I'd like you to define what a composite material is and give me one example.

Then I'd like you to name one physical or working property of carbon fiber that makes it useful in products such as bicycles.

And lastly, I'd like you to identify one advantage and one disadvantage of using composite materials in products.

Good luck.

Come back to me when you've got some great answers.

Let's take a look at our answers.

So part one, I asked you to define what a composite material is.

So a composite material is made by combining two or more materials to create a product with improved working and/or physical properties.

And a great example is carbon fiber.

Part two, one working property of carbon fiber is that it is lightweight, which makes it ideal for use in products such as bicycles, where reducing weight improves performance.

And then lastly, advantages and disadvantages of composite materials.

So advantage, composite materials can have excellent strength-to-weight ratio, meaning that they are extremely strong in one way whilst remaining lightweight, which is useful in products such as aircraft and cars.

The disadvantage is that composite materials can be expensive to produce, making them less suitable for low-cost products, obviously, with the exception of laminates for tables and things.

Onto question four, why are modern and composite materials often difficult to recycle?

Part five, explain why the use of composite materials improves the function of products.

I'd like you to use an example product and composite to support your answer and explain how the composite achieves the desired effect.

Good luck.

Come back to me when you've got some answers.

Let's take a look at our answers.

So part four, composites and modern materials, are often difficult to recycle due to the mixing or layering, with regard to composites, of the materials.

Part five, I chose glass-reinforced polymers.

That's because I'm thinking of the spaghetti demonstration.

So, glass-reinforced polymers are a composite material commonly used for roofing due to their excellent performance.

The glass fibers within GRP are arranged at varying angles, which, when the polymer sets, provides strength in multiple directions and enhances impact resistance.

This makes GRP roofs both strong tensile and compression and lightweight, without adding unnecessary weight to the structure.

Without the glass fibers, the polymer would be brittle and prone to damage.

Additionally, the polymer ensures the roof is water- and corrosion-resistant, whilst its flexibility allows it to be molded into a variety of roof shapes, offering versatility for different architectural designs.

Take a little look at your answers, see if you've managed to cover lots of points that were set out in the question.

This brings us to the end of our lesson today.

Let's recap and summarize what we have learned.

Modern materials are continually being developed through the invention of new or improved processes.

Modern materials have improved working and/or physical properties.

Examples of modern materials include Nomex, Teflon, Fastskin, microencapsulation, PLA, Kevlar, and composites.

Composite materials combine the properties of two or more materials, but without being mixed at a chemical level.

Examples of composite materials include GRP, carbon fiber, and laminates.

Modern materials, including composites, provide exciting opportunities for designers and users, but both have advantages and disadvantages.

Well done with all your hard work today.

Take good care.

Bye, bye, bye.