07x05 - Applications

[bunniefuu]

It's time to make the ice cream. And

today on Dragonfly TV, the nano factories

are cranking out the sprinkles, fixing

broken bones in the cracks, and the lab

ninjas are Kung Fu fighting.

Major funding for Dragonfly TV is

provided by

the National Science Foundation,

supporting education and research across

all fields of science and engineering.

The National Science Foundation, where

discoveries begin.

Dragonfly TV. Dragonfly

TV.

This is Dragonfly TV Nano, and I'm Eric.

Some nanotech inventions are so amazing

that they sound more like science

fiction. Let's start with invisibility,

as in Harry Potter's cape.

Okay, Eric, good trick, but you can come

back now.

Someday, nanomaterials may be capable of

bending light rays so perfectly around

something that it seems to disappear.

Nanotechnology may make invisibility a

reality. Today, nanoscientists are making

stuff we already use better.

Check out these glasses. On a rainy

day, they would fog right up.

But if I wipe them with this

cloth covered with water

absorbing nanoparticles,

they don't fog up at all.

Even simple nano products like this can

be complicated to create, so scientists

are always looking for better ways to

make things. Which brings us to a riddle.

What do nanoparticles have in common with

a tent?HmmKeely and

Connor are about to find out. All

the small things

Hi, I'm Keely. And I'm Connor. And we're

totally into the great outdoors.

Hey, man, what's up?Connor is one of the

oldest friends that I have. He leaves

best qualities as a friend and she can be

trusted and relied on. Connor is a good

friend because you can do anything,

and it'll still be fun.

We were testing out our tents to get

ready for a camping trip, and we noticed

that my tent seemed to pop up instantly

by itself almost. But Connor's tent took

him a long time to put up.

No! Why did you do this to me?Isn't that

weird?My tent put itself up. I heard the

museum is working on a new exhibit about

nanotechnology and how things put

themselves together. You want to go check

it out?OK, we went to the Children's

Museum of Houston. We heard they have

some stuff about new nano inventions that

can put themselves together.

Hey guys, welcome to the Children's

Museum of Houston. We were just comparing

tents and Connor's took like forever to

put up, but mine only took a few seconds.

Y'all are very observant. What you saw

with those tents is something similar to

something called self assembly. What is

that?Self assembly. It's

something that nanoscientists are

actually studying in their labs right

now. We also have some great programs

going on today, so I'll catch up with

y'all later. See you. OK, cool. Bye. Bye.

The Children's Museum of Houston has a

lot of cool things to see and do. We

checked out the telephone, man. The kid

lift, the baby chicks, the Mustang, and

the Matter Factory exhibit. The Matter

Factory exhibit had stuff all about

nanoscience and nanotechnology. Hey, I

wonder what this is. Looks like my

brother's air hockey table. They're

magnetic. Hey, look, they're forming to

make patterns and stuff. Hey, look, this

one made a flower on its own. Really?

That's cool. Let's see what happens when

we break it. It just goes back. It goes

back to the flower pattern. It's like

they know where to go. Hey guys,

this is he found our self assembly

component. This is actually a model. This

is a way we can show what's happening at

the nanoscale. So with self assembly what

happens is each of these molecules, they

bond a very specific way and they do the

exact same thing every time. You know

what else uses self assembly?What?

Snowflakes. Really. Yes. A snowflake is

made of a tiny little ice crystals, and

they form through the same process of

self-assembly. Then we checked out

Keith leading a game about self-assembly.

There were special rules for how all the

parts were supposed to fit together. Put

your blue glove against one of the other

blue gloves, and you need to place your

red glove next to one of their red

gloves. When we got the rules right, it

turned out we made a human snowflake.

You're a giant snowflake.

Then, we went to the inventor's workshop

and learned that there's two main ways of

constructing things. Top-down

manufacturing and bottom-up

manufacturing. Top-down manufacturing

is like when an artist starts out with a

big block of marble and sculpts it down

to a specific shape. This is harder than

it looks. Yeah, don't quit your day job.

And bottom-up manufacturing means

building things up brick by brick. like a

house. I'll huff and I'll puff and I'll

blow this house down. No!

So this is where self-assembly comes in.

The scientist says that it's a special

type of bottom-up manufacturing where all

the really small pieces come together on

their own. So if these blocks are

nano-sized, then that means they build

themselves up. I wonder what that would

look like.

Awesome!We

wanted to learn more about self-assembly,

and Keith sent us to visit his friend

Mike at Rice University.

Here's a variation of that game you can

play during breakfast. Check this out.

Exigzibayuelaboop.

That was the name of my Nano dog.

These exotic words are coming to us

courtesy of self-assembly. The

molecules on the milk surface want to

stay stuck together, but those pesky

floating letters just keep getting in the

way, so there's a lot of pushing and

pulling going on. We'll get back to

nano-sized self-assembly with Keely and

Connor in just a bit. But first, time to

collect your thoughts for the

nano challenge.

Today's nano challenge is all about

water. Here's a list of things you

definitely do not want in your drinking

water. But when this particular thing is

nano sized, it can help take

toxins or pollutants out of drinking

water. Is it a salt,

B soap, C

sewage, or D

rust?See

if you can figure it out, and I'll give

you the answer at the end of the show.

Yes, this is a tricky challenge, but if

you get really stuck, I'll be back with a

clue. And now it's time for Killy and

Connor to assemble themselves in Mike's

lab. All the

small things

Hey, look at that guy. Who are you?Oh,

hey, kids. I'm Mike. Why are you up there?

I'm trying to think big thoughts. Big

thoughts about nano. You guys want to do

some nano experiments?Yeah, definitely.

All right. One, two, three.

Whoa! You're in my lab. Ow.

I don't do that too often, but welcome.

Dr. Mike Wong is a chemical engineer at

Rice University. He's super smart with

nanotechnology and has a team of

scientists to help him with his

experiments. We're doing a lot of

interesting things with self-assembly,

and one thing that we're doing is to make

capsules. You may be wondering, well,

what are capsules?Let's pretend this

water balloon is a capsule. This water

balloon contains water inside here, but

let's pretend it contains a drug molecule

and we're going to put around it a shell

that protects it from the outside. We

make it nano-sized. Then we can take that

and put it inside the human body. Another

thing that we're trying to do with our

nanocapsules is to be able to clean up

oil spills out in the ocean. So how do

you make things like that so small?Yeah,

can we make some nanocapsules?Absolutely.

Self-assembly.

We mixed up our chemicals and a solution

of nanoparticles. Then we added the food

coloring. Mike told us that as we mixed

the solution, the nanoparticles

surrounded the food coloring and trapped

it in the form of capsules. What you have

there is nanocapsules. Think of

that capsule that you can't see enlarged

to this. Those are like these?Yep. When

you added all the four chemicals

together, the nanoparticles form a shell

around the dye molecule. All that happens

because of self-assembly, and really that

whole process of self-assembly occurs

instantly. Mike put our solution of

capsules into the centrifuge. The

centrifuge spun our solution really fast

to separate the capsules from the liquid.

We checked out the capsules after they'd

been centrifuged. The capsules were all

at one end, kind of clumped into a

powder. We learned that there were

hundreds of millions ofcapsules in the

solution we made. How do you know the

particles are really nano-sized?Ah, I'm

glad you asked. Come, I'll show you.

Mike showed us some pictures he'd taken

of the capsules with some of his

microscopes. Here's a picture of what you

guys made. Whoa. Whoa. They're not-- I

thought they'd be smooth. Uh-uh, they're

not smooth at all. Very textured. Take a

look at this picture right there. Whoa.

Is that like even more zoomed in?Yep.

These are about 10 nanometers big,

actually. And this is an example of what

we would call bottom-up manufacturing,

because we make a lot of these capsules,

and that's the power of self-assembly. We

can make lots of things very quickly,

very instantaneously. So what else can

you make using self-assembly?Like

buildings or bridges?We wish we could do

that. A lot of scientists are interested

in making big, complex things using

self-assembly. It's going to take a long

time for that bridge to build itself. How

long?Oh, right now, if I had to guess,

an infinite number of years. Wow, that's

all I'll tell you. It's a long time.

There's a version of a self-assembly

chemistry recipe that some chefs are

actually using to create self-assembled

food. Self-assembled food?Cool.

Mike gave us a special self-assembly kit

to take away with us. It has chemical

ingredients that are safe to use with

food. So we decided to bring it home and

try an experiment of our own.

Ice Cream Sundae's coming right out.

Cool, let's get our recipe. We mixed up

something called alginate and water in

our kit from Mike. Then we added some of

our favorites: strawberry, chocolate,

maple syrup, and mint. We dropped our ice

cream toppings into calcium chloride and

watched them self-assemble into tiny

drops. just like how the nanocapsules

self-assemble at Mike's lab.

No! Whoa! That is so cool.

Looks like a worm. Let's eat him. I

think we have to wash him off first.

So, what do you think about

nanotechnology?It's the best.

Awesome.

One reason self assembly works the way it

does is because at the nano scale,

everything tends to be shaky.

Just imagine bees in a beehive,

non-stop movement, jostling

collisions.

And with nano-sized things, this jiggling

motion and bumping into each other

actually makes it easier for them to

stick together. It's nature's way of

putting a puzzle together. Now let's meet

Tejal, who uses nanotechnology to get

medicine to where it matters most.

Let's go. Hi, my name is Tejal Desai, and

I'm a bioengineer. A bioengineer is

somebody who designs and

Makes devices or technologies that can be

used the human body in

medical applications. So what we do in

the lab is similar to making a cup of tea

with a tea bag. When you make a cup of

tea, water molecules enter the

semipermeable membrane of the tea bag and

allow the tea molecules to flow out. This

is similar to what we do with our

nanoporous capsule. Please explain. Let

me show you what I mean by the nanoporous

capsule. Here are the actual membranes

that we. we make. What we do with these

is we put them on the ends of these

teeny capsules that look something like

this, but is 100 times smaller.

We fill the capsule with either medicine

or a protein like insulin, and we'll

implant these into the body, and they'll

be able to deliver medicine into the

body for the right period of time. So one

thing about working at the nanoscale is

that even a piece of tiny dust can be

bigger than the entire experiment, so

that's how we actually have to do things

in the clean room. My student Mark's in

the clean room right now. Check it out.

So I'm working on making wafers that have

patterns on the nanoscale. We're trying

to study how cells from your eye

interact with these little patterns. In

the future, this could possibly regrow

eye tissue, and that would allow blind

people to see again. The

best part about my job is working with

the students that I have.

I'm working on better ways to deliver

medicine. I study new ways to treat eye

diseases. I study how to repair heart

muscle. I make medicine easier to

swallow. I work on regenerating heart

muscle.

When I was a kid, I loved to build

things. I loved exploring the outdoors

and biology and nature. And so when I

heard about this field of bioengineering,

I thought that was the perfect place for

me. I said I was going to be a biomedical

engineer when I was in high school, and I

actually didn't realize that 20 years

later, I'm still doing it, and I love it,

and, you know, it's been fabulous.

Work like Tajil's is also helping cancer

patients. Nanoparticles can be injected

that find and destroy the tumor and leave

the rest of the body alone. Now for

another way to get rid of bad stuff. It's

back to the nano challenge. Which of

these four things is no good for your

drinking water, but when it's nano sized,

can help make the water safe to drink?

Is it salt, soap, sewage,

or rust?Here's a clue. You won't

find this stuff where there's no oxygen.

But now it's time for a non-toxic trip

with my friend Zoomer. Yo, Zoomer.

Now, if we're looking for nano, why are

we heading toward a giant clay pot?

Hang on tight and you'll find out.

That smooth red clay is actually a tangle

of tiny fibers magnified now



tree bark than baked clay. Let's get a

little closer.

Wow. Who would have thought there's nano

structure in here?You see, there are

even more tiny fibers connecting all the

particles, which make the pot strong

enough to hold things like egg salad or

your marble collection. Let's get even

closer.

Oh, check out these light and dark

layers. One is water, the other is a

mineral. And each layer is only four

atoms thick. We've never gone this small

before. Way to go, buddy.

That's right, Zoomer. Well, we've

survived the atomic scale. Time to zoom

out.

Wow. How about that?Zoomer took us beyond

nano into the smaller world of atoms.

Next up, a breakthrough of a different

kind. Someday, new

nanomedical techniques may mean that

breaking a leg won't be that much worse

than scraping your knee. A skater named

Adam is down in the half pipe.

Paging Dr. Nathan. Paging Dr. Coble.

I'm Nathan. And I'm Coble, and we come

here to watch skateboarding tricks.

Skateboarding! These guys do some great

moves, but they fall a lot when they're

skating. Our friend Adam just broke his

leg in a bad crash.

I won't be able to skate for two months,

and I've been wondering if there's a

faster way to heal my bones than just

putting on a custom waiting. The Science

Museum has a whole lab full of bones. We

could go there. Sure. Let's go. Whoa,

whoa, whoa. We went to visit the Oregon

Museum of Science and Industry to see

what we could find out about how to get

bones to heal faster. This is cool. It's

all about old bones here. Yeah, from

dinosaurs. Look how they put the pieces

together. It looks like they just

plastered it together. I wonder if they

could do that with people's bones. Let's

go look at the rest of the museum. One,

two, three,

four! Man, that's so cool.

Watch. Yeah.

We looked everywhere, and we were about

to give up when Adam found something.

Guys, come over here. This is the injured

nerve, and then you inject the

nanoparticles, and then it fixes.

Whoa. Hey, look. It also says that

he can do it to the bone. Let's go see if

there's there's anybody else in the

museum. We asked around and they sent us

down the hall to see Tom, a visiting

scientist from Brown University.

We found Tom in the physics lab and he

told us about a cool new way to fix

broken bones. We are looking at

nanotechnology that can be used and

injected. into your bone so that you

don't need a cast. This blue material

right here is our nano material.

Wow, that's really sticky. Yeah, if we

put this into your bone, you could see

how it could easily pull together the

pieces of your bone and then allow it to

heal. The other thing neat about this

material is it solidifies at body

temperature. The leg

bone's connected to the

knee bone.

So this is what it looks like after it's

been injected into bone. What happens is

this dissolves while new bone is growing.

But wouldn't the materials that

disintegrated be bad for you?No, it's

actually perfectly natural in your body.

These are the two ingredients,

hydroxyapatite, and this is what gives

bone its strength. The other component

are these nanotubes, in which this serves

as the glue that brings together the

pieces of hydroxyapatite to heal bone.

Tom explained that the hydroxyapatite is

made of calcium and minerals. And the

sticky nanotubes mimic the collagen in

real bone. Then he showed us a

SEM image of real bone and his

nanomixture on his portable scanning

electron microscope. This is a high-power

scanning electron microscope. Can this

microscope see nanoscale?Yep, it sure

can. So you can see here an

image what actual bone looks like. And

you notice that there's a crack that's

going in there that we created

artificially. But then we have these

other lines that are going across that

basically show collagen and

hydroxyapatite, which gives bone its

strength. This is the nanotube, and

here's the mineral, the white dots. And

that's the hydroxyapatite. He asked if we

wanted to help out and experiment with

different mixtures of nanotubes and

hydroxyapatite in our own model bones.

very nice to meet you, Mr. Bones. Okay,

so we know that human bones have 30%

minerals. What other mixtures should we

use?How about one that's over 30%,

like... 50%?Sure. And

then one that's lower. Yeah, 10%. 10%,

yeah, yeah good idea. We also decided to

make mixtures using just nanotubes and

just mineral powders to see how well they

would work. We used sponges to

make the monobones because they're porous

and absorb things, like real bones.

First, we cut sponges to mimic a break.

Then we repaired them with our mixtures

of minerals and nanotubes. After that, we

hardened the sponges in the oven.

Man, I can't wait to break those bones.

Then it was time to test out how well our

nano mixtures glued the sponges together

using a special gadget that Tom gave us.

We put the sponges under a stick of wood

with a bucket hidden from it. We filled

the bucket with water until the sponge

broke and then weighed the water.

Give

me something to break Give me something

to break Damn We're gonna start with the

yellow, where it's gonna be the 10%

mineral. So now we're going to start

adding water. And stop when it breaks.

And how much weight is that?8.6.

Then we did a mixture of 30% minerals,

like human bones have.

And how many pounds is that?10

pounds. Okay, let's try the 50% one now.

All right, and... We've

got 11 pounds. I think we should go back

inside and figure this all out.

We decided to convert the weights from

pounds to grams. Then we made a chart to

see which was the strongest. We also

discovered that when we used all

nanotubes or all mineral powders, the

sponges didn't stick together at all, so

we placed them at zero grams on our

chart. Look at this trend.

The more minerals, the stronger the bone

gets. It's like 10% could be like older

people's bones. Brittle. Yeah, and



out and they have stronger bones.

You know, I bet if you made the mix

stretchier, you could also fix muscles.

Yeah, and maybe in the future, instead of

going to a doctor's office. You go to a

nano repair shop.

OK, so that is exciting.

But what I want to know is where was this

stuff when I broke both of my arms and

had to wear itchy casts all summer long?

HuhCan you tell me that?

Nanomedicine will do more than just fix

broken bones faster. It will help

replace valves in a weakened heart

or repair damaged cells in our bodies

one at a time. Or it will take a tiny

drop of blood and do detailed tests on

something no bigger than this computer

chip. What else could nanomedicine help

with?Unclogging arteries?

Microscopic surgery?Wait a nanosecond!

Do I think we should rush now technology

without knowing all the side effects?No.

I think that anything with nanotechnology

should be tested before it's sold. They

could have some bad side effects.

Really smart people should figure that

out. I would think that it's pretty

dangerous. Something might go wrong with

it when people are already buying it.

Well, let's see. Definitely depends on

the circumstances. We didn't know the

good and bad things about, like, going

into space and things. But we did that

anyway, and look how that turned out. If

they knew for sure that it would work,

even if they didn't know all the side

effects, that they could go ahead with

it. If there was a cure for cancer,

I would put it out there right away,

'cause think of all the lives we could

save. I'm just not that type of

risk-taker. If we use it and it turns out

to be a giant disaster, that would be

a disaster. The scientific method was

created for a reason. Those guys

had some interesting points. Go to our

nano message boards and tell us if you

think nanotechnology should be in the

products we use. Here's how. Click

on over to the Dragonfly TV website at

pbskidsgo.org. Stream a cool

DFTV video, try your hand at the new

Nanobots game, or tell us what you think

about nanotechnology. It's your place to

share your ideas. Now for the

Nano Challenge answer. This is something

you definitely do not want in your

drinking water. But the nano sized

version of this stuff can help take

toxins out of water. Is it a

salt, B soap,

C sewage, or D

rust?The answer is

D rust. Crazy, but true.

Nanorust, or iron oxide, is

used to remove arsenic from drinking

water. These tiny rust particles

actually bind with the arsenic, and

magnets can then pull both of them right

out of the water. Kind of like this.

Here are nanorust particles in water.

Watch what a simple magnet can do. The

magnet pulls all the rust to one side,

and the water is now clear. So

can nano save the world?

Well, Nano can't make every problem

disappear. But we'll be back

for more Big Ideas from a Small, Small

World on DFTV Nano.

All the small things

True care, truth brings

I'll take one lift

Your ride, best

Say it ain't so I will not go

Turn the lights off Carry me home

Na, na, na, na, na, na,

na, na, na, na,

na,

na Major funding for Dragfly TV is

provided by...

The National Science Foundation.

Supporting education and research across

all fields of science and engineering.

The National Science Foundation, where

discoveries begin

PBS Kids.