Are you feeling curious?

Yes.

Today I'm curious, Crew.

Here it goes.

It's a smashing good time.

Oh, my.

As we expand our minds to explore matter and its properties.

Material science can be pretty sweet.

Support for Curious Crew is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages, all teaching lifelong saving habits.

More information is available at MSUFCU.org also by the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world class educational resources by investing in nonprofits committed to education and career readiness.

More information is available at ConsumersEnergy.com/foundation and by viewers like you.

Thank you.

Hi, I'm Rob Stephenson and this is Curious Crew.

Welcome to the show, everybody.

We always like to start every episode with a couple of discrepant events because discrepant events stimulate curiosity.

That's exactly right.

And I've got some fun ones for you today.

And in fact, Bhavya, I'm going to ask you to help me out.

What have I got here on this little paper towel?

I think they're two coils.

Two coils.

Exactly right.

And in fact, I have a pan of hot water, and I'm going to drop each one of those inside.

And, Bhavya, what might happen if I drop those coils inside?

Hm?

Well, maybe the lighter one will float and the heavier one will sink.

So let's start with this one first.

And, Bhavya, that was a good prediction.

That one really did sink.

And let's take a look at this one and see what happens.

Oh, my goodness.

Now, that's really, really strange.

Okay, I'm going to fish this out and let that sit for just a minute.

And I'm going to ask Silas to do me a favor.

So, Silas, can you describe that object for me?

A blue glass cup.

Now, Silas, I'm going to place it inside this bowl, and I would like you to predict what will happen if I add some hot water in there.

I don't know.

It's probably gonna get wet, don't you think?

Okay, let's put some water in here and let's see what might happen to our cup.

Interesting.

I'm just going to let that sit for just a moment.

And in fact, you know what?

I would like to try this one more time.

I'm going to coil this wire around this dowel one more time and let's see if we have a similar result.

Let's see what happens.

Oh, it did it again.

And Nava what do you notice going on over here?

The color from the cup is like bleeding into the water.

I have another identical cup that I left in the water for 15 minutes.

I want to show you what it looks like now.

Oh.

Oh, wasnt that funny?

15 minutes.

Wait a minute.

So we've got this wonder wire and the disappearing glass.

This is kind of perplexing.

I'm going to invite three of you to do a little scientific modeling to see if you can explain these phenomena By the end of the show.

You can use your background knowledge, evidence that you learn who wants to participate in a modeling moment today.

Okay.

Nitya, Annlyn and Rishabh.

Excellent.

Now, does anyone have a guess what were going to be investigating today?

What do you think?

Nava, What do you think?

I'm thinking that it has something to do with material properties.

Oh, great thinking.

We're investigating material science.

Get your microscope eyes ready, because we're zooming in on micro structures.

That surprised me when the wire sprung back into shape.

Yeah, but why did only one wire do that?

They're both made of metal.

There must be something different about them on a micro scale.

Well, yeah, I agree.

Remember when the color came off of the glass in the water.

I wonder if the glass would fully dissolve if left in the hot water.

The materials that things are made of have always been important, even dating back to different historic periods like the Stone Age, Bronze Age and Iron Age.

But the study of materials science emerged with the engineering of ceramics and metals as people discovered they could heat and reshape materials.

So then in the late 1800s, Josiah Willard Gibbs connected an object's physical properties to its atomic structure.

A materials microstructure is a very important part of materials science.

So when we start thinking about material science, there are some important things we have to consider, like the arrangement of atoms, the bonds between the elements and the stress that those microstructures can handle.

And I have the greatest thing for us to test today, and I think you can guess what it is.

What are we testing today, Nava?

Chocolate!

And are you enjoying that smell Nava?

Yes!

I knew shes was.

Now, Max, tell me what is different with those three bars of chocolate?

Well, this one just has plain milk chocolate in it.

Right.

This one seems like it has rice or something in it.

And this one looks like it has almonds inside of it.

You are spot on, milk chocolate, rice crisp in there.

And those almonds.

Now, what we're going to do is we're going to support a chocolate bar and I'm going to hang this cup right from the center of the chocolate.

And what I'd like to know is how many of these 40 gram washers can those bars withstand before it's too much and they break?

Which one do you think is going to be able to support the most mass?

What do you guys think?

This one.

Okay.

You're saying rice, you're saying, oh, almond, I love it.

What do you think Ekaansh?

I'm thinking milk chocolate.

Okay.

I think it's time for us to test it.

All right.

And we're going to measure the mass each time.

Let's start with the almond bar first.

Get the sling on there and let's start adding some washers.

One, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13, 14, 15.

So what was it?

15?

Okay, we're going to mass this.

You guys, You ready?

Okay, let's try the rice now and see what happens.

One, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13, 14, 15, oh, its 15, 15.

We have a tie.

Let's get a mass here.

And it should be the same, shouldn't it?

Yeah.

Okay.

Time for the milk chocolate.

Let's see how we do with this one.

Get ready to count.

One, two, three, four, five, six, seven.

Only seven.

Let's mass this one.

291.

Those extra materials, are they actually reinforcing the chocolate and making those bonds stronger?

In fact, they are sometimes the almond bar will break right away, depending upon where you put the string.

Now, let's think about something else.

Let's test the strength of the bonds on these.

Bobby pins.

Look close at those.

Ekaansh What are you noticing between these three bobby pins?

Well, this one looks a shiny black.

This one looks kind of gray, and this one's partially discolored.

Excellent.

Okay, I'm going to ask you each to grab the shiny black one.

This is a brand new bobby pin.

Grab the legs of it and see if you can bend it and stretch it apart.

Nava, what are you noticing?

It's really stiff.

Okay, put that one down.

Grab the middle one that's gray.

Now, before you try to bend this one, let me tell you what I did to this.

The next two pins experience something called thermal processing.

And what I did is I heated them both up in a flame.

Let's go ahead and grab this and see what you notice.

I noticed that this one was, like, very weak.

It's super weak.

Isn't that strange?

So before we test this last one, safety first here, let's get some goggles on and grab that last pin.

I got to tell you something before you pull on it.

I put this one in a torch as well for 20 seconds and immediately dunked it in cold water.

That's called quenching the metal.

Now, let's go ahead and see what happens.

Oh.

Oh, my gosh.

It broke.

Didn't.

Okay, go ahead and take off your goggles and let's explain what happened.

The heat with those pins actually changes the micro structure, the one that was gray, that cooled slowly.

Those atoms were able to move around and re-crystallize, but it really weakened the pin.

Now, the last one that I quenched, it's super, super brittle.

So the amazing thing about material science, it's the micro structures that will determine the strength.

One category of material science is metal alloys, where different metals are melted and combined to make a new material.

Over 3000 years ago, the Sumerians combined 90% copper with 10% tin and ended up with a stronger metal bronze.

Today, material scientists still work with traditional metals like copper, but they're also experimenting with titanium, aluminum and magnesium.

The combination of different metals has led to the development of very strong alloys that are also lightweight, perfect for automotive and aerospace industries, ready for lift off.

So we're going to take a look at another example of material science, another category, and I'm going to start by taking these hard candies and we're going to put them in the microwave here for 13 seconds.

We're going to let those cook for just a moment.

And in the meantime, Chloe, would you take a look at these items right here and tell me what they have in common?

They're all shiny and circular, Shiny and circular.

Excellent.

And believe it or not, they're a category together.

Oh, we're ready.

This is actually going to be a category of ceramics and glass.

Now, it seems strange to think about those hard candies as glass, but let's see if we've got this soft.

Now, what I'd like you to do is each take a little wooden skewer and poke into those candies and see if you can get a soft spot and see if you can start pulling them out.

What are you noticing there Nitya?

They're like, really like, stringy and stringy.

Oh, my gosh.

Now, if we could use our microscope eyes for just one second and look at these different materials.

If I were to look at ceramic, what we would see is actually a crystallized structure.

But these different kinds of glasses, one made of silica and one made of isomalt.

Those are actually made from sugar beets, believe it or not, the atoms are going to be amorphous, which is really strange, which means they're just random.

They just move all over the place and they will flow when they start to get hot.

But at the same time, they will solidify when they get cool.

Now I'm going to ask you to try something, Nitya, since you've got that right there, see if you can pull it apart.

And I'm going to ask you to just oh, yeah, put that part on your tongue.

It's good.

And it also kind of like, is like, dissolving really fast.

Okay.

It's dissolving on your tongue.

Now, this actually makes sense.

If you ever had, like, cotton candy.

Know when you eat cotton candy and sort of dissolves on your tongue?

that's actually from the heat from your mouth.

That amorphous glass is actually dissolving, which is really, really interesting.

Now, there's something else I want to show you over here.

You can put that down for just one second.

And I want to point these things out.

What are you noticing here, Chloe?

They look like glass.

Yeah, a little glass beads.

Now, would it surprise you to know that all of those are made from this borax powder, though?

Are they different colors?

Now that is an excellent question.

You'll notice we have two different kinds of metals.

Copper and this one is called Nichrome.

Now, depending upon the material that I use, I can actually end up with a different color change.

So what I did was I just took a little stem little loop and I put it in a torch flame.

And as soon as it was really hot, I dipped it in the powder, put it back in the flame, all the water started to evaporate it out.

It started moving around and becoming amorphous and transparent.

And then suddenly it started changing color from the metal.

So here's an example.

If I have this copper one and I put it in the flame and I move it to the outside where there's a lot of oxygen, I end up with a blue color.

Isnt that cool?

So the red one was red because it was closer to the flame.

Exactly right.

It's closer to the flame, less oxygen.

You end up with a different color.

Now, the nichrome really interesting because this is a metal alloy that's made from nickel, chromium and iron, three different metals, a lot of different potential color there.

Now, these are really pretty, but not nearly as edible or as fun as the sugar glass fibers.

Keep in mind, material science can be tasty too.

Material scientists study ceramics and glass, which are both brittle materials.

The microstructure of glass is interesting because the atoms are not orderly, like in crystal structures found in most ceramics.

When we think of glass, we usually imagine a window or drinking glass, which are made from silica, a pure sand.

But the crew investigated glass made of sugar.

In both cases, the microstructures share characteristics.

They are both transparent liquefy when heated and solidify when cooled.

Although sugar glass is weaker, it is perfect for candies.

Yum.

STEM Challenge So have you been having fun investigating material science today?

Yeah.

I'm so glad.

Now we have a great STEM challenge for you.

We are actually going to be exploring and making a composite.

In fact, you're going to be making reinforced cement.

And I know that each team has determined what you're going to be using for your reinforcement.

You ready to get started?

Yeah.

All right, Let's go for it.

I think we should start like, you know, scooping it in the first 20 scoops.

Dr.

Rob has us making a cement paste that's going to harden later on.

And then we're going to test its dropability.

One...two.

The materials we're using at our table are the cement powder, water and for our reinforcement, we're using rice.

Our reinforcement were toothpicks.

In this case, we're using bobby pins.

Lets be quiet.

Shes counting.

We had to pour 20 spoonfuls of water in the cement powder.

Ten.

Thats Ten.

Its very splashy.

Chloe is measuring out the 20 teaspoons to put in the powder.

And then Annlyn is mixing it and making it into a paste and pouring it in the bowl.

Well, it's not as thick as I thought it would be.

And then I'm adding the reinforcements.

Ten.

Halfway there, we decided that Nitya would be spooning the water.

Max is going to mix it using the skewer.

I'm going to pour it, after adding the rice, the mixture has a really grainy texture initially, but the more we mix it, the more liquid it gets.

So it's like there's still some powder at the bottom It just looks like a really unappetizing smoothie right now I'm not sure how our cement will hold up, but I'm hoping it won't break over all the rice.

And you can see it inside the cement, too.

Now, I guess you can probably figure out what's going to happen next.

We need to let them harden.

And once they're set, we're going to test their strength by dropping them.

It's called a drop test.

This should be really interesting.

So it looks like our cement is finally hard and we're going to do a drop test to see how well those bonds can stay together.

Let's talk to your table first, Ekaansh what reinforcement materials did you use?

We used toothpicks and we put them in two rows of four.

One, two, three, four.

Then crisscross.

One, two, three, four.

Like a tic tac board.

Oh, nice.

Okay.

Do you think it can handle the drop test and stay together, or do you think it's going to break?

I am going to think positive.

because Im an optimist sometimes.

Okay, so let's be hopeful that it stays together.

Yeah.

All right.

Let's give this a whirl.

Here it goes.

Oh, okay.

That was interesting.

I think it's time to test another one.

We got to clean this one up a little bit, so we're ready for the second test.

And, Chloe, what reinforcement materials did your team use?

Used six bobby pins.

We added three on the bottom and then three like across on top.

Excellent.

And do you think it's going to stay together?

Possibly.

Let's give it a try.

Here it goes.

Oh, we got some bigger pieces on that one, though.

So our last one to test.

And Max, tell me, what reinforcement material did your team use?

We used 50 milliliters of rice.

50 milliliters of rice.

And do you think it's going to stay together?

I'm 80% sure that it'll hold up.

80% sure.

Okay.

Here we go.

Oh, what do you notice in there, Max?

It did not survive.

Did not survive.

So isn't that interesting?

When we did those brawny chocolate bars that rice did a pretty good job bonding it.

But here within the cement, not so much.

Now, we could change the ratio of ingredients and make many, many more of these and see if they could stay together.

Better by making these really strong composites.

Perhaps one day you'll be a material scientist or engineer and design your own composites.

Composites describe different materials that bond together.

Concrete is a perfect example that combines cement, water, sand and rock.

And by adding different reinforcements, it can be used for many purposes.

Rubber tires are composites, too.

Fibers are added to the rubber to increase tire strength and the fiberglass in your bathtub is also a composite made from glass fibers embedded into a plastic matrix.

Engineers experiment with composites to discover how material properties might change when combined, and then design new solutions to everyday problems.

Amazing.

Now we've investigated a lot of different examples of material science.

We've looked at metals, glass, ceramics, composites.

But there's another category we haven't explored, and that's polymers.

That's what makes up plastics.

And we're going to actually make a really interesting polymer, first of all, Annlyn, what have we got right here in the cup?

We have one tablespoon of glue.

Perfect.

And another ingredient Bhavya.

This is two tablespoons of borax solution.

Excellent.

And the final ingredient, Silas.

One tablespoon of cornstarch.

Okay, Now, what I'd like you to do is you're going to pour the borax solution in with the glue and then stir it with a popsicle stick.

Ready?

Okay, let's go ahead and try that.

So what's really interesting is the glue by itself is a polymer already.

Now polymers are interesting.

It's like they're long molecules, almost like long wet spaghetti.

And so they just sort of flow past each other.

But as soon as you put in the borax, it cross-linked and it starts to cluster these molecules together, totally changing the microstructure, pull your sticks out, it's going to be kind of wet.

You can squeeze off the moisture, pull it off of the stick, set the stick aside, and you can use this towel to dry your hands to squeeze it out and then start trying to rub this polymer in your hand.

Here is one that I did that is dry, but notice how it's stretchable, but it also breaks, which is really unusual.

And you're also going to notice that it still has some sticky quality to it.

Right?

But if you dry your hands, there you go.

You're getting it.

Now, check this out.

Let's see if it has any sort of bounceability.

Oh, my.

Really good bounceability.

Polymers are really strange.

Now, there's another one I want you to try for just one second.

Set that down on your towel for just a moment and grab that other putty that you've got there.

Once you see, what you notice.

Its very stretchy, very stretchy.

Silas, that is like, Oh, that is unbelievable.

Did you do that really slowly?

Yes.

Okay.

Now what would happen, you guys, if you pull them really fast?

Now, isn't that strange?

So when you did it slowly, it stretched like crazy.

When you did it fast, it broke quickly.

This is what we call a viscoelastic material.

In other words, if we hold them still, they'll start to lose their shape.

But at the same time, if they fall, they can bounce.

We can stretch them.

Pretty cool.

Polymers are amazing, and it's all about the micro structures because the micro structures in material science can be quite entertaining.

Are you curious about careers in science?

Hi, I'm Genesis and today I'm here with Camille Corr Chism Camille, Can you tell me where we are and what you do?

I'm a packaging engineer and we are at the school packaging at Michigan State University.

And here we take various materials that we use in packaging and we test them for strength, durability, just to make sure they're not defective.

What exactly does a packaging engineer do?

We basically are looking at whatever the product is.

How does it need to get shipped and delivered to the consumer?

What kind of testing is done to ensure products are safe?

It depends on the product.

So when you look at material properties, you have to understand exactly what you're trying to protect from packaging.

It's like a puzzle.

You're putting so many things together and to make them all come together in a package is great.

Camille Corr Chism showed me that art and engineering are a package deal.

Explore your possibilities.

And now back to Curious Crew.

So we saw how heat affected the microstructures of the process pins.

Maybe the wonder wire was annealed and that's why it was so flexible.

Well, we know metals are affected by thermal processing, so we need to know what types of metals are in the wires.

I agree.

I think the disappearing glass might have been sugar glass like the candies we heated up.

Maybe that could explain why the glass dissolved in the water.

So if you had fun investigating material science today.

Yeah.

Im so glad.

Now it's time for us to return to our discrepant events to see what we can explain and what you figured out.

Nitya, what have you figured out about this wonder wire?

Well, we know that both wires were metal alloys, but we believe that the heat caused the wonder wire to go back to its original shape.

Yeah.

When the materials are heated up, the atoms are rearranged their microstructures.

You're all so clever now.

In fact, you're right.

These are metal alloys.

The steel is actually made from iron and carbon.

And we notice when we put it in there, nothing happened but this wire.

This is interesting.

It's called nitinol wire and knits know is made from nichrome and titanium.

The strangest thing about the microstructures of these is there is what's called a high temperature phase and a low temperature phase.

It's room temperature right now, so I can bend it around.

It's really, really weak.

But as soon as we subjected to some heat, oh my, it instantly reverts back to its high temperature crystalline phase, which is amazing.

And you probably thinking, gosh, what would be an application for something like that?

Well, we use nitinol wires in eyeglass frames and orthodontic braces, sometimes in cell phone antennas, temperature systems.

And it was even on the Mars rover, which is amazing.

Okay.

Rishabh.

What have you figured out about this disappearing glass?

Well, we know it's not ordinary glass.

Maybe it's a type of sugar, and that's why it dissolves in water.

You're exactly right.

It is the same kind as these hard candies.

It's made from isomalt again, which is from the sucrose of sugar beets.

Now, you might have noticed when we first looked at the cup, you might have noticed how thick that was, because if we start pouring water in there, it starts to dissolve.

This is sugar, which means that glass is fully edible and it's actually tastes like vanilla.

But of course, as soon as it gets subjected to water, those atoms start moving around in that amorphous system, they will start to flow, melt and then solidify when they dry 15 minutes.

And it looks like that.

Keep in mind, this isomalt, it's the same thing you're going to find in your hard candies.

So I'm sure you'll all agree material science can be pretty sweet.

So remember my friends, stay curious and keep experimenting.

Get your curiosity guide and see more programs at WKAR.org.

Support for Curious Crew is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages while teaching lifelong saving habits.

More information is available at MSUFCU.org also by the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world class educational resources by investing in nonprofits committed to education and career readiness.

More information is available at ConsumersEnergy.com/foundation and by viewers like you.

Thank you that's surprising the wire and it That's surprising the wire... That was the one.

Yeah yeah yeah to be on his crew for six years it's been a really great experience.

Oh yes.

I knew it.

Meeting all new kinds of people and learning all new kinds of topics.

And I'll really miss this.

1007 modeling moments.

Take one Good job Rishabh, Good job Rishabh I think I nailed it.