Lesson video

Hello, my name's Mrs. Taylor, and thank you for joining me for our lesson today.

Our lesson today is Smart Materials in Design, and this is part of the Developments in New Materials: Supporting New Parents unit.

The outcome: I can identify smart materials, uses, and applications.

There are three keywords: stimulus or stimuli, which is the singular or plural, meaning something that encourages activity or change; material property, which is a characteristic of a material; and response, which is a reaction to a stimulus.

There are two parts to our lesson today: define smart materials and explore smart materials.

Let's begin with define smart materials.

A material property is a characteristic of material.

Material properties can also describe how a material behaves under different conditions, such as when it's stretched, heated, or exposed to electricity.

These properties help determine if a material is suitable for a specific application.

Examples of material properties can include color and appearance, the aesthetical qualities of a material.

For example, acrylic is available in many colors and has a smooth and shiny surface finish.

Strength, how much force a material can handle without breaking.

For example, steel has high strength, making it ideal for building structures.

And thermal conductivity, how well a material conducts heat.

For example, copper has high thermal conductivity, so it is used in cooking pots and electrical wiring.

Stimulus or stimuli is something that encourages activity or change.

The Mimosa pudica plant closes its leaves in response to the stimuli of touch, as we can see here in this gif.

Smart materials change their material properties in response to an external stimulus.

They revert back to their original form when the stimulus is removed.

They display smart behavior.

Here, we have a check for understanding.

Read and complete the sentence.

Pause the video.

Brilliant.

Let's check.

Smart materials can change their material properties in response to an external stimulus.

Well done.

What could the stimuli be?

We have four images.

Have a think.

How did you get on?

Did you get these correct?

Sunlight could be a stimuli, or water or moisture, or pressure, or temperature.

Well done.

This gives designers and engineers exciting opportunities when developing new and existing products.

Jacob says, "The lenses in these glasses go darker in response to being in sunlight, and then go back to their original tint when not in sunlight.

" One or more material properties of smart materials can be changed.

For example, color, opacity, shape or electrical conductivity.

Here, we have a check for understanding.

In this example, sunlight is the, A, property, B, stimulus, or C, smart material?

Pause the video and have a go.

Fantastic.

Let's check.

That's right, it's B, stimulus.

We now move to task A.

Part one is define the term smart material, and part two is sort the material properties and stimuli into the correct columns.

We have temperature, color, electrical conductivity, shape pressure, light, opacity, and water or moisture.

Pause the video and have a go.

Wonderful.

Let's have a look at some of the answers you may have come up with.

For part one, you could have said, "Smart materials change their material properties in response to an external stimulus.

Once the stimulus has been removed, the smart material goes back to its original form.

" And part two, material properties include color, electrical conductivity, shape, and opacity, and the stimuli are temperature, pressure, light, and water or moisture.

Well done.

We're now going to move to the second part of our lesson.

We're going to explore smart materials.

This is really exciting.

Let's go.

This is a smart material known as thermochromic ink.

The stimulus making the mug respond to its environment is the heat from the hot water.

The material response is that it changes color.

Thermochromic means to change color in response to heat, thermo meaning heat, which is the stimulus, and chromic meaning color, which is the material property response.

As well as being a fun material with its color-changing properties, thermochromic materials can be used to indicate a temperature or warn users of danger.

Thermochromic ink has been used to create baby and children's health and safety products.

For example, spoons can change color to warn if the food is too hot, bath toys can indicate if the bath water is too hot, and mugs and kettles can change color with hot water.

Here, we have a check for understanding.

What is the stimulus for a thermochromic material?

Is it A, sunlight, B, water or moisture, or C, temperature?

Pause the video and have a go.

Fantastic.

Let's check.

That's right, it's temperature.

Well done.

Laura says, "The stimulus making this coloring book respond to its environment is water.

The response is that the coloring book changes color.

" This is a hydrochromic material.

Hydrochromic equals change color in response to water, hydro meaning water, which is the stimulus, and chromic, which we already know means color, which is a material property response.

hydrochromic ink nappies use color indication when a new nappy is required, the image of the guitar disappears.

No-mess coloring books simply need water to activate them.

What is the stimulus making these beads respond to the environment?

Pause the video and have a think.

How did you get on?

Jun says, "I think it is UV light.

" What is the response?

He says, "The beads change color.

" This is a photochromic material.

Photochromic means change color in response to sunlight, photo from the Greek word meaning light, which is the stimulus, and chromic meaning color, as we've already discovered, and that's the material property response.

Glasses that change their opacity to sunglasses in response to sunlight are an example of a photochromic smart material.

Also, festival wear using UV lighting is another example.

Another example is stickers for children that change color to alert parents when to apply sun cream.

Here we have a check for understanding.

Which product is a smart material example of hydrochromic ink?

Pause a video and have a go.

Well done.

Let's have a look.

That's right, it's C.

The no-mess coloring book uses water as its stimulus and the color changes as the response.

Well done.

This is a paperclip made from shape memory alloy, which is abbreviated to SMA.

It is bent out of shape, but when dropped into the warm water, it returns to its original shape.

It has memory of its original shape.

The stimulus is warm water, and the response is returning to its original shape.

Shape memory alloys, stents are tubes made from a shape memory alloy threaded into arteries.

The stents expand with a rise in body temperature to allow increased blood flow and open up the arteries.

Glasses return to shape after bending.

Braces made from nitinol gently exert pressure to push the teeth back together.

And memory foam pillows or mattresses, these are all examples of shape memory alloys.

What is the stimulus making this material respond to its environment, do you think?

Pause the video and have a think or talk to the person next to you.

Wonderful.

How did you get on?

Aisha says, "I think it is the heat from the hot water.

" And the response?

She says, "It can be molded into another shape.

" This is polymorph.

It is used for modeling orthopedic or ergonomic aids and prosthetics.

Poly is from the Greek word meaning many.

The stimulus is heat.

Morph is from the Greek word meaning shape, and this is the material property response.

It can be molded into lots of different shapes.

Here, we have a check for understanding.

Which smart materials use heat as their stimulus?

Is it A, polymorph, B, photochromic, C, hydrochromic, or D, thermochromic?

Pause the video and have a go.

Fantastic.

Let's check.

That's right, it's both A and D.

Polymorph and thermochromic use heat as their stimulus.

Well done.

Here is another example of a product with a smart material.

This is a smart material known as piezoelectric.

The stimulus making these shoes respond is pressure on the soles.

The material's response is to generate a small electrical charge, which enables the LEDs to glow.

It works the other way too.

They can move or make vibrations when electricity is sent through them.

Piezo is from the Greek word piezein, which means to press or to squeeze.

This is the stimulus.

Electric is simply electric, and this is the material property response.

Piezoelectric materials can detect sound or vibration and act as triggers for alerts, like baby monitors.

Piezoelectric materials convert vibrations from the strings into electrical signals for amplification in an electric guitar.

Here, we have a check for understanding.

What is a stimulus for a piezoelectric material?

Is it A, electrical conductivity, B, pressure, or C, temperature?

Pause the video and have a go.

Wonderful.

Let's check.

That's right, it's pressure.

Well done.

Set foams, formable foams, set elastomers, and formable elastomers are a type of smart material that can change its materials properties instantly from the response of impact.

These special liquid foams are fluid or sponge-like in their normal state, but become instantly hard under impact.

They are used to produce protective wear.

We now move to task B, identify the stimulus for each smart material.

They are listed in this table: thermochromic; hyperchromic; shape memory; photochromic; piezoelectric; and polymorph.

Pause the video and have a go.

Great.

Let's see how you got on and look at some of the answers you may have come up with.

Thermochromic, the stimulus is heat, hydrochromic, water or moisture, shape memory, heat, photochromic, sunlight, piezoelectric, pressure, and polymorph is heat.

Well done.

And we continue with task B.

The image shows a bathroom toy.

Part two, explain how a smart material could be used to improve the toy.

And part three, discuss how smart materials have been used to improve the function and/or performance of products, and use two examples to support your answer.

Pause the video and have a go.

Wonderful.

Let's have a look at some of the answers you may have come up with.

Andeep says, "The bath toy could use a hydrochromic material.

Therefore, when the toy is played within the water, it could change color, adding to the playful experience.

" And Lucas says, "Smart materials appear to think by sensing the conditions in their environment and responding by changing their material properties in a controlled way.

" Izzy says, "An example are shape memory alloys, which can return to their original shape when heated.

That's the material properties.

These are used in glasses frames because if they get bent, they can go back to their original shape, making them more durable.

Another example are thermochromic spoons.

These have improved standard spoons by adding an extra safety element.

The color of the spoon can tell the adult that the food is too hot for the baby or child to eat.

Overall, smart materials make products more useful, safer, and more convenient for people to use.

" Well done.

We now have a summary of our learning today.

Smart materials change their material properties in response to an external stimulus.

Smart materials give designers and engineers exciting possibilities when developing new products.

Stimuli include sunlight, water, moisture, pressure, and temperature.

Material properties that can be changed include color, opacity, shape, and electrical conductivity.

Thermochromic, photochromic, hydrochromic, piezoelectric, polymorph, and SMA are all examples of smart materials.

I'm really pleased you could join me for our lesson today.

Thank you and well done.