0:04

Welcome to tex Stuff, a production of

0:06

I Heart Radios How Stuff Works. Hey

0:12

there, and welcome to tech Stuff.

0:14

I'm your host, Jonathan Strickland,

0:17

executive producer with I Heart Radio

0:20

and I love all things tech,

0:22

and today we're going to look at a tech

0:25

Stuff classic episode that published

0:27

back in February two thirteen. This

0:29

one has the title tech Stuff

0:31

Plays with carbon Nanotubes.

0:34

Yes, carbon nanotubes the stuff of

0:37

the future that is persistently

0:39

the stuff of the future and never

0:42

seems to be the stuff of right

0:44

now. I mean that's not entirely

0:46

fair. We've done a lot of work in carbon

0:48

nanotubes and there's been a lot of progress made, but

0:51

it's been one of those futuristic things for

0:53

a long time now. So let's listen

0:56

back on two thousand thirteen Jonathan

0:58

joined by Lauren Vogelball as

1:00

we talk about carbon nanotubes. First,

1:03

we thought that we would talk a little bit about why carbon

1:05

is cool, because um so so it's

1:08

it's an element, incredibly

1:10

uh popular

1:13

element here on the planet Earth. It is way

1:15

up there, it is. It is in fact,

1:18

the fourth most abundant element in the universe

1:20

by mass um after hydrogen, helium,

1:22

and oxygen and the second most abundant

1:24

element in the human body. Yeah yeah, we

1:27

are what is known as carbon based

1:29

life forms. Yeah. Um. And all of this

1:31

is made possible because carbon atoms are these

1:33

nifty little hexagons made with six electrons

1:36

um. They

1:39

they bond very easily with one

1:41

another. Actually, if they bond in

1:43

a lattice structure, which is a hexagonal

1:45

structure, do you have a sheet of that? So

1:48

you've got a whole bunch of carbon atoms that are molecularly

1:50

bonded to one another in this hexagon

1:53

pattern. Here in the South. I like to

1:55

call it chicken wire. Anyone

1:58

who anyone who lives in any story a rural environment

2:01

who has seen chicken wire, that's kind of

2:03

what a sheet of these carbon

2:05

atoms and molecular structure look like. We

2:07

call that sheet graphing. So

2:10

let's say say you've got this sheet of graphing,

2:13

which is essentially two dimensional,

2:15

right, because adams don't really

2:18

have a lot of thickness to them, so

2:20

they are you're you're talking about with and

2:22

length, you're not talking about depth. And I mean that's

2:24

you know, one atom thick that's thin enough to call

2:27

it two dimensional. Absolutely.

2:29

So you've got the sheet of graphing. Let's

2:31

say, then you roll the graphing

2:33

into a I don't know, burrito

2:36

like structure. It's not

2:38

necessarily going to be filled with cheesy

2:40

beany goodness. You

2:43

know, I kind of want a carbon nano to burrito

2:45

now. I am craving burritos

2:48

like you wouldn't believe. But but no, No,

2:50

that's what we call a carbon nanotube. You take that sheet

2:52

of graphing, this this hexagonal

2:55

molecular structure of carbon, and this is just carbon

2:58

you and you roll it up and that's carbon

3:00

nanotube. But you know, carbon is kind of an amazing

3:02

thing anyway, because carbon can

3:05

take on so many different forms, right

3:07

right, Yeah, I mean it's what diamonds and graphite

3:10

are both made of, and it's totally different

3:12

a little little bit. I mean, you know that's you've got.

3:14

You've got the hardest substance, the hearts, natural

3:17

substance known on Earth, right,

3:19

and then you've got what you put in pencils.

3:22

Essential So yeah, something soft enough

3:24

that paper is paper,

3:27

paper is its match, right

3:29

right? Yeah? Yeah, So so this

3:32

is something that we call allotropes. Now,

3:34

an allotrope you know, you're like, what the heck

3:37

is that? Well, if you if you've studied chemistry,

3:39

you know. So I apologize to all the chemists

3:41

out there who are screaming at me because I'm assuming

3:44

they don't know what an allotrop It's okay,

3:46

I know. You know. Also, y'all can go just get a soda

3:48

for the next about So, an allotrope

3:51

is any of two or more physical

3:53

forms in which an element can exist.

3:56

So you we have these elements that can exist

3:58

in different physical forms, and carbon

4:01

is a perfect example. Lauren was just pointing

4:03

out diamond versus versus

4:05

a graph fite. So you've got these two

4:08

very different kinds of forms, but

4:10

they're still the same basic element. Uh

4:13

well, carbon nanotubes are very similar

4:15

in that way. We'll talk a bit more about

4:17

the different properties

4:20

that carbon nano tubes can have and

4:22

why they can have different properties, but

4:25

we need to lead up to that. Yeah,

4:27

yeah, yeah, Well this entire carbon

4:29

nanotube business was discovered in by

4:33

Sumio Ijima, I believe is the way

4:36

that you pronounce it. Um apologies to my Japanese

4:38

teacher. Um. Although

4:40

research into into creating these

4:43

sheets of graphine stretches back into the nineteen

4:45

fifties. Um, and all of these

4:47

are there. They're actually two processes for making

4:49

them. One of them I'm not extremely

4:51

familiar with, and it's written all the way down at the bottom of my

4:53

notes, so we're going to cover that one later. That's

4:55

a wet application, the general

4:58

way of making carbon nano tubes as a RYE application,

5:01

and you thermally strip carbon atoms

5:03

off of carbon bearing compounds. Wow,

5:07

that sounds complicated,

5:09

or at least violent and violent. Violent

5:12

at an atomic level, that is extremely

5:14

violent. Yeah, and

5:16

so this is well, this is

5:18

what produces these these extremely

5:21

these atom thin sheets UM

5:23

that that you then roll into a

5:25

tiny tiny tube and by tiny tiny, I mean

5:27

about a nanometer or two

5:29

in diameter UM and just you

5:32

know, just to just to recover this nanimeter

5:34

is one millionth of a millimeter, so

5:36

it's one billionth of a meter, So it's small,

5:39

right, And then you at

5:41

least for the longest time, Uh,

5:43

these these carbon nanotubes could

5:46

be at most about a millimeter

5:48

long. Now that's changed recently, right,

5:50

right, But I mean even a millimeter long

5:52

is pretty impressive because that's that's a million

5:54

times as long as it is. Why that's I

5:57

mean, that aspect ratio is incredible.

5:59

I mean, it's one of the things that really made carbon

6:01

nanotubes a fascinating

6:04

thing to look at, because you're thinking, if you're looking

6:06

at the dimensions, by one dimension, this

6:08

is incredibly tiny, and by the other, in comparison,

6:10

it is ginormous. I mean, think

6:13

about the technical term. Think if you saw

6:15

a bus that was a million

6:17

times longer than it was wide

6:19

or or or long cat. If long CAT were so

6:21

long that it were a million times

6:24

longer. Thank you, Thank you Lauren for bringing

6:26

it directly into an analogy

6:28

that is relatable to everybody. I

6:31

was going with the bus, What was I thinking? I

6:33

was mostly thinking I would not want to be behind

6:36

that bus. I bet they would make really wide

6:38

right turns. Like we're on we're on the

6:40

internet, Okay, we if we don't incorporate cats

6:42

into the conversation, we're going to be fired,

6:45

right, We're lost. But anyway, Yes,

6:47

this is one of those amazing properties

6:49

of of carbon ano tubes.

6:51

The other thing that I find really interesting

6:54

is that carbon ano tubes will

6:57

have very different properties

6:59

depending up on how they are rolled.

7:02

Because it's mostly the direction of

7:04

the role. So it really is the how that

7:06

those hexagons I was talking about in the graphing,

7:09

how they are aligned in comparison to

7:11

the actual role of this

7:13

sheet. Uh. And depending

7:16

on how you do it, it can behave like

7:18

uh, like a metal, so a conductor,

7:21

so it will conduct electricity. But if you

7:23

roll it a different way, like at a slightly

7:25

different angle. And if you guys are having

7:27

trouble visualizing this, just take a sheet of paper

7:30

and roll it along the short side,

7:32

or roll it along the long side, or roll

7:34

it along the diagonal. These are all

7:36

the different kinds of ways you can roll sheets of graphing

7:39

and you get different properties. So you roll

7:41

it one way, it acts metallic like a conductor,

7:44

so it's conducting electricity. You roll

7:46

it another way it acts like a semiconductor,

7:48

which means that in some situations

7:50

it does conduct electricity and in other situations

7:53

it acts as an insulator. This gives

7:55

it an incredible flexibility as

7:57

far as applications are concerned. You can use

7:59

it in all sorts of electronic applications,

8:01

which we will get to a little

8:04

bit when. Yeah, and it also

8:06

depends on what kind of you can roll them into all kinds

8:08

of different interesting shapes using

8:11

using an atomic force microscopes also

8:13

called scanning force microscopes, which

8:15

are which are things that have these these

8:17

tiny bitty little nanimeter probes on the end

8:19

of them, and you can use them to basically poke

8:22

around a nanotube until it's

8:24

the right shape, the right shape for your process.

8:27

This is pretty amazing. I mean, we're talking about

8:29

manipulating things that are

8:31

just slightly larger than the atomic

8:33

scale, right, I mean, it's something

8:35

that's really difficult to to visualize.

8:38

Now, there there are some neat ways

8:40

of kind of getting an idea of how precise

8:42

we can be these days. My favorite, we've talked

8:45

about it on the Tech Stuff podcast in the past.

8:47

My favorite illustration

8:49

is that ibm UH several

8:52

years ago used a similar

8:54

type of microscope to manipulate

8:57

individual atoms to spell

8:59

out I B M on

9:01

a silicon wafer. That is delightful.

9:04

Yeah, so you're talking about being able to when

9:06

when we're able to manipulate individual

9:08

atoms, then obviously this is

9:10

we've got this level of precision that to me is

9:13

mind boggling. I mean, it's really exciting.

9:15

But some of the other properties of carbon nanotubes

9:18

is again depending upon the way you you you

9:20

roll these tubes, it can be

9:22

an incredibly strong material,

9:24

stronger and lighter than say,

9:27

steal, hundreds of times stronger than

9:29

steel. Yeah, according to to

9:32

to some Well, you know, here's

9:34

the thing. There's a theoretical limit

9:37

to the tensile strength of carbon

9:39

nanotubes, and then there's the limit

9:42

that we've actually seen. Right,

9:45

and as we get better about

9:48

creating nanotubes than those two numbers

9:50

get closer together. But in

9:53

general, in the experimental phase you might

9:55

not see as incredible a

9:58

display of strength as you would aspect

10:00

when you start running the numbers via you know, mathe

10:03

But for an example, you

10:05

could take a a cable that

10:08

if you were to cut the cable and look at

10:10

and measure the diameter you're talking about like a

10:13

a one millimeter diameter of

10:15

this cable, nanotube

10:18

of that size could hold approximately

10:21

six thousand fo or

10:23

fourteen thousand pounds.

10:25

And that's and and and a millimeter, I mean, that's that's

10:27

what like like about the width of a human hair. Well,

10:30

a millimeter would be one millionth

10:32

of a nano, one million times the size

10:34

of a nanometer. That really brings it

10:36

into perspective one million that

10:38

I ruined my own joke. To

10:41

be fair, I'm not working on very much sleep, right,

10:43

I think I think a millimeter is about it's about the size

10:45

of a head of a pin. Actually, the hair

10:48

a human hair is like a few hundred

10:50

thousand nanometers, depending

10:52

upon the person's hair, because human hair

10:54

comes in a but

10:58

but yes, I mean, the point being that you're talking about

11:00

an incredibly thin cable that

11:02

could hold an amazing

11:04

amount of weight considering the dimensions

11:07

of the cable. Now, granted again,

11:09

this is theoretical, you know, when we talk

11:11

about real carbon nanotubes and the real

11:14

experiences we've had, it's a little

11:16

bit different from that. But the potential

11:18

there is to build certain types

11:20

of materials, certain types of products

11:23

using this stuff that can have fantastic

11:26

properties. And just

11:28

to be clear, we're saying stronger than

11:30

steel. That's really mostly tension

11:33

strength when you're talking about um

11:35

other types of impact. Because

11:38

carbon nanotubes are hollow, they

11:41

can buckle. So let's

11:43

say that you have just somehow

11:45

you have managed to make one carbon nanotube

11:48

that's you know, Lauren Height, and

11:50

then you have a force impacting

11:53

that along the side of the carbon

11:55

nanotube, so it's not pulling on the nanotube,

11:57

it's pushing against the side right into

11:59

the chewy center. Right. Well, that chewy center

12:02

might just buckle and the carbon nanotube

12:04

bends and you think, well, that was But

12:07

it's the same sort of thing like saying the strength of a rope.

12:09

The strength of the rope is how much weight

12:12

it can pull, not pushing

12:14

against the rope in the middle of the middle of the rope.

12:16

It doesn't make any sense. And let's be pulped

12:18

taught, And that's a whole different version of physics

12:21

that we would need to get into right right exactly.

12:23

But but that's one of the other things to to

12:25

keep in mind is that even though it is an

12:28

incredibly strong material and theoretically

12:30

one of the strongest materials we've encountered,

12:33

uh, that's only in specific

12:35

use cases. It's not like you

12:38

would build a carbon nanotube wall

12:40

and it would be immune to everything else

12:42

known to man, right, although

12:45

I'm sure there are ways you could do that, like

12:47

maybe with some sort of woven fabric made

12:49

out of carbon nanotubes, but an

12:51

individual carbonanitude it's not the case.

12:55

Let's take a moment to thank our sponsor,

13:04

and now we'll return to our regularly scheduled

13:07

tech stuff podcast. Alright,

13:09

so, um, so there are there are many many applications

13:12

that these nanotubes can be used for. Like,

13:14

like we mentioned before, their engineers

13:17

are looking at incorporating them into building

13:19

materials, perhaps for vehicles. I mean,

13:21

imagine if you had a vehicle that was six

13:23

times lighter than than the cars

13:25

that are running around today, right that and

13:28

that. If you're wondering why you would want a light car,

13:30

one reason is that it means that you don't

13:32

have to use as much fuel to push

13:34

that car around. A lighter

13:36

car means less work for the engine to do.

13:38

If if the engine has to do less work, it theoretically

13:42

needs less fuel. So we

13:44

could end up with cars that

13:46

are still gas powered

13:48

but end up requiring far less fuel

13:51

have greater efficiency.

13:53

Or we could of course use it in other like

13:56

hybrid cars and you know you're again

13:58

you're placing or even electric vehicles

14:01

or something like this airplane or yeah, yeah,

14:03

there's some great airplanes would be fantastic

14:05

because, as anyone has pointed out, if

14:07

you're talking about someone who's who's green conscious

14:11

and they're trying very hard to live a green

14:13

friendly life style. They basically need to avoid

14:15

airplanes entirely. One flight on a plane

14:17

and you have just like you know, you're essentially

14:20

erasing any good you're doing with your

14:22

entire green life at home. And that's

14:25

that's just a hard reality of what

14:27

it takes to move. Yeah,

14:31

so that's a great example. You actually pointed

14:33

out something else. A future use of

14:35

this technology could be something that we did

14:37

an episode of tech Stuff about a

14:39

few years ago. Space elevators.

14:42

Space elevators. Yeah, these are these are

14:44

really nifty things. If you guys have not heard of

14:46

this, um, you you should have

14:48

by now, you're a bad tech stuff listener. But

14:51

that's okay, because you can fix that. I

14:53

still love you, Yes, yes,

14:56

no, No, I just

14:58

I had to. I had to moderated

15:00

of Facebook thread the other day. I am being

15:03

the social media here. It has stuff works. I'm if

15:05

people are are being jerks on Facebook,

15:07

they I'm the one who has to clean it up. So don't

15:10

be jerks on Facebook, y'all. Um. It's

15:13

a very special episode of tech Stuff, But

15:17

no elevator, space space

15:19

elevator. No, well, I mean, okay, the point

15:21

of my story here, I've start started to stutter. Excellent.

15:24

Um, the point of my of my story

15:26

was that you shouldn't be a jerk

15:29

on Facebook. Now, No, I had a point. My point,

15:31

well, let me let me let me at least explain what space

15:33

elevator is. How about that? Because I'm

15:35

dying here, I can I can at least

15:37

give it a shot. So let's

15:40

say. Let's let's say you put an object

15:42

into orbit, stationary orbit around

15:44

the Earth. Okay, so it has to be uh,

15:47

it's the object is sort of a counterweight,

15:50

essentially, So you've got a counterweight orbiting

15:52

the Earth, and the thing connecting the counterweight

15:55

to Earth is a very strong

15:57

cable, and you use the

16:00

elevator, which is essentially attached to the cable,

16:02

to transport in anything.

16:05

Really, it could be people, although cargo

16:07

would be a lot easier than people, because with people

16:09

you gotta worry about, I don't know, keeping them alive

16:11

and stuff, moving them to Yeah,

16:14

I guess if we're moving dead people, it's okay.

16:17

So if we want to have a space cemetery out

16:19

there, I wouldn't mind that, except

16:22

that I actually plan on donating my body

16:24

to science fiction. Uh so the

16:27

the Yeah, you have an elevator that has this

16:29

counterweight out there. Okay, you're

16:31

just pick up that. Now I'm with you. I'm with you,

16:34

and keep going so the elevator

16:36

can travel up the cable. The the nice

16:38

thing about this is the based on this design,

16:40

you might be using things like lasers to actually

16:42

power this elevator. Uh. The elevator

16:45

wouldn't have things on it like thrusters,

16:47

like rocket thrusters, the way we would with a a

16:49

traditional rocket ship to get stuff into space.

16:52

It would mean that it would take uh less

16:55

energy in theory to deliver

16:58

payloads to utter space. You wouldn't have

17:00

to worry about problems like uh

17:04

catastrophic failure when you're talking about

17:06

propellants that can be incredibly

17:08

dangerous under the wrong conditions. And

17:11

also, I mean, just like we were saying, if you if you take

17:13

one airline flight, you're basically erasing

17:16

the entire good that you've done on your carbon footprint all

17:18

year. You know, the cost of launch in

17:20

terms of fuel and and just

17:23

people and manpower is is ten

17:26

thousand dollars per pound. That's per

17:29

kilogram that's a bunch. So you've

17:31

got you've got this need to

17:33

find a cheaper way to get stuff into utter space

17:35

if in fact we want to do that thing

17:38

that which we do, I mean I do, yeah,

17:40

because there's lots of fascinating stuff out there. So

17:44

space elevators are a good way of doing that. But one

17:46

of the problems is that how do you create a cable

17:48

that's going to be strong enough and small

17:51

enough to make this a reality?

17:53

And carbonano tubes might very well be

17:55

the way that we solve

17:58

that problem. Now, for a long time everyone

18:01

said, okay, well here's the barrier, the barriers

18:03

that we've got. We've

18:05

got this exactly. Yeah, yeah, we can make

18:07

carbonano tubes, but there are a millimeter long

18:10

at most, and so we don't have to make

18:12

a whole bunch of them and tie the ends

18:14

together teeny little bows

18:16

in order to make a big, long one for the cable,

18:19

but relatively ineffective. Yeah, so we'll

18:22

get into some some new forms of

18:24

manufacturer that have made that less of

18:27

a problem. But even now we're still

18:29

talking about this is science fiction

18:31

as far as we're concerned. It's it's feasible,

18:35

but not possible. Given our technology

18:37

right now, right now, But there are other applications

18:40

that we could use carbonanotubes

18:42

and including things like, uh like

18:44

conductive plastics, So we can

18:47

make electronics out of plastic

18:49

materials and run carbonano

18:52

tubes through the plastic, creating

18:54

them a conductive layer, so

18:56

that you can actually make products

18:59

even small more than they are today. So

19:01

instead of having a casing that is

19:04

covering up the electronics, the casing would

19:06

be part of the electronics. You could have you

19:08

know, a credit card, thin smartphone.

19:11

Yeah, yeah, that would that would turn More's

19:13

law right on its point he had. Yeah, yeah, there's

19:15

some pretty neat stuff that could potentially

19:17

happen. We also could have things like smart

19:19

fabrics, so clothing

19:22

that could have carbon nanotubes in it that might

19:24

do things like monitor conditions

19:27

like it could it could end up powering

19:29

various sensors. This would obviously be very important

19:32

in uniforms like space suits

19:34

or first responders outfits

19:36

for things like firefighters, things like that, you know,

19:39

things that that could benefit

19:41

from this. But even from a more consumer

19:44

standpoint, we could even have I don't know,

19:46

like clothing that tells you how active

19:48

you are and whether or not you're getting enough exercise

19:51

and don't even have to put on a speedometer a

19:53

little Nike fit wristband, right,

19:55

you'd be fine. You just you know,

19:57

you put on your clothing, and that tells you or

20:00

may say things like, for Heaven's

20:02

sake, wash me. You

20:05

know that that goes out to everyone I

20:07

went to college with. There

20:10

other clothing applications. I mean, maybe not so much

20:12

for daily use, but but carbon antotubes

20:14

could be used to create some really terrific body armor.

20:17

Oh yeah, sure, yeah. Again, we're talking about the

20:19

incredible strength, and if it's woven the right way,

20:22

you're talking about something that could have a

20:25

great applications for anyone

20:27

who might be in military or law enforcement

20:30

to provide a level of protection that is

20:32

really unheard of at this point. I mean,

20:34

we've got some great technology out there

20:36

to keep people protected, but this would be

20:39

a step of a huge step above

20:41

that. Hey guys, twenty nineteen,

20:43

Johnathan again, you know the one you hate, because

20:45

it's time for us to take another quick break. Part

20:55

of the problem here is that we're talking about

20:58

a material that's still a little challenging

21:01

to manufacture, especially in mass quantities.

21:03

But there have been improvements in

21:06

carbon nanotube manufacturing processes

21:09

very recently. Yeah, actually, I'm we were,

21:11

we were, and you know, we're recording this in early

21:13

January, UM two thousand and thirteen.

21:16

And actually just today the Internet

21:18

told me that, um that Rice University has

21:20

announced a macroscopic hundreds

21:23

of meters long mass producible

21:25

carnin carbon nanotube thread.

21:27

Yeah, this is this is incredible

21:30

news because again, before we were talking about

21:32

nanotubes that were a millimeter long, and that

21:34

was considered huge. Now we're talking hundreds

21:37

of meters. That is such

21:40

an enormous leap that it it boggles my

21:43

mind. And it's all through this this

21:45

wet method that they used

21:47

to manufacture carbon nanotubes. Yeah, wet

21:50

spinning method in which, um, and I'm

21:52

sorry, I'm going to read this directly from my notes, which is probably

21:54

a terrible thing to do, but in

21:57

which clumps of nanotubes are dissolved in a bath

21:59

of some acid stuff squirted

22:01

through small holes to create long strands, and

22:04

then the strands are wound into a big

22:06

spool until they dry out. That's

22:08

pretty incredible. So really, the way

22:10

I understand that is that we have dissolved

22:13

the carbon nanotubes until they're essentially

22:15

a liquid. You put them into what

22:18

is essentially a nozzle, you

22:20

squirted out in what is essentially like

22:22

a giant icing thing where your

22:25

favorite kind of cake, and you get

22:27

this long string of carbon nanotube. That's

22:30

exactly the way you wanted to be until

22:32

you get that, you spoil it up and

22:34

there you got You got a hundreds, hundreds of

22:36

meters long carbon nanotube. Yeah, it's it's

22:38

the thickness of a human hair. Um uh

22:41

And and not like I was saying earlier that you

22:43

know, that's that's big. That's a bunch of a bunch

22:45

of h space things

22:49

measurements of stuff. It's

22:52

much much larger than say, you know, a

22:54

single carbon nanotube would normally be you know

22:56

again one billionth of a of

22:59

a meter in die ameter. It's

23:01

larger than that. Yes, And there there's

23:03

a video and on the Internet of an LED

23:05

lamp being both suspended and powered

23:08

by this thread, right, so so that it's

23:11

this tiny like human hair

23:14

with cord that's holding

23:16

a lightbulb, and the light bulb is lit

23:18

because power is going

23:21

going through and and it's it's

23:23

completely suspended that way. So you think about

23:25

that and you're like, all right, so we've got

23:27

this very thin, very strong stuff

23:30

that can provide power across it. This

23:32

could revolutionize electronics.

23:34

Oh absolutely. And there's also there's also

23:36

been a bunch of research into health applications

23:39

for this. UM. It can be used as a delivery system

23:41

for drugs and vitamins because carbon antitudes

23:43

are are so bitty that they can they can really get

23:45

in there, you know, they you can you can attach you can

23:47

attach stuff to them and send them in

23:50

through things and and be really effective

23:52

as an antioxidant. UM they naturally

23:54

pick up free radicals in UH in

23:57

blood systems. I used to do that in college. Oh

24:00

my, um you

24:02

can. One of one of the really cool bits of research

24:04

that I saw had people UM

24:07

sticking an antibody onto the end

24:10

of a nanotube UM and then letting

24:12

a blood sample pass through it, and different

24:15

kinds of tumor cells or viruses

24:17

will get trapped by that antibody and

24:19

then UM, so you can you can test for all kinds

24:22

of things without having to do any expensive

24:24

lab work in the field in a

24:26

couple hours. Interesting. Of course, this

24:29

also leads to a dark discussion

24:32

in that carbon nanotubes may

24:34

also be depending

24:36

upon their their structure, may

24:39

be extremely hazardous to our

24:42

health. And uh, there are a couple of

24:44

reasons for this. One is that when you're talking

24:46

about things that are on the nano scale, their

24:48

properties change fairly dramatically. You

24:50

can have materials that act as conductors

24:53

in the macro scale, but on the nano scale

24:55

they might be insulators. You also

24:58

may have things that on the macro scale are perfectly

25:00

safe, but on the nanoscale are toxic.

25:03

And one of the things that concerned people fairly

25:05

early on in the research of carbon nanotubes,

25:08

and has been studied extensively since

25:10

then, is that carbon nanotubes,

25:12

depending again on the specific structure

25:15

that you've designed for them, bear

25:18

a striking resemblance to this

25:20

substance called asbestos. And

25:24

and for for for those young uns out there, this was

25:26

an asbestos is a substance that used to be used

25:28

in a lot of insulation. Um. Yes, it's

25:30

fire retardant. Fire retardant, which

25:32

which is great. I mean that's less fire

25:35

good. Yes, yes, fire fire

25:37

bad. As Frankenstein's Monster taught

25:39

us. However, Um, you know it

25:42

was made up of these of these small, pointy particles

25:45

that people would aspirate and

25:47

it would get stuck in the linings of your

25:50

lungs and your other internal organs and cause

25:53

cause lesions and metalalithiomia. No,

25:55

that was not the word mesol.

25:58

Yes, yes, the form of

26:01

cancer that the lining around

26:03

your organs, that's specifically what what

26:05

we're talking about here, but but more specifically

26:08

the lungs because you would breathe in these

26:10

particles, and they're small

26:12

enough so that they can, uh, they

26:14

can infect a cell. Essentially,

26:17

they can, uh, they can penetrate

26:19

a cell. That's the best word for it, penetrate a cell.

26:22

But they are large enough so

26:24

that the body's immune system

26:26

cannot easily get rid of them, which is

26:29

why it becomes a very dangerous

26:31

substance. And the

26:33

carbonanotubes bear some physical

26:36

resemblance to those needle pointing

26:38

fibers. Now, according to at

26:41

least some research, I was reading

26:43

one report that was kind of interesting,

26:46

and I cannot pretend that I follow

26:49

it completely because my my medical knowledge

26:51

is uh, plucky and adventury.

26:54

No wait, I'm sorry, that's my military knowledge. Um

26:57

by the very model of a modern tech stuff.

26:59

Podcaster they it was

27:01

from an online library, is actually from

27:03

the Cancer and Aging Handbook. And the

27:07

study suggested that carbon

27:09

nanotubes could penetrate

27:12

cells, but they did so in a

27:14

different way than asbestos

27:17

particles did, Like they both could

27:19

penetrate cells, and they both could cause similar

27:22

outcomes. So, in other words, there is some

27:24

evidence that carbon nanotubes could in fact

27:27

be carcinogenic, but they

27:29

do it in a different mechanism,

27:32

Like there's a different mechanism for how

27:34

they are they get enveloped by

27:36

other cells or by cells,

27:38

I should say not other cells, but by cells. And

27:40

so the research actually

27:43

suggests that there might be ways of creating

27:45

carbon anotubes where they do not behave

27:47

in this way where they are causing

27:50

cancer. They just kind of hang out, right,

27:53

And that's one of the other problems about carbonano

27:55

tubes is they have this bio

27:57

persistence, meaning that if they are

27:59

in a biological entity, they

28:01

do not tend to break down right there.

28:03

They're so strong and sturdy. Yeah, they

28:06

don't react. They're nonreactive when it comes

28:08

to that too, So you don't have it just you

28:10

know, decompose into some other material

28:13

or get absorbed and then

28:15

you know, they're harmless, that's the problem. They don't

28:17

do that. So, but there

28:20

might be ways of engineering carbon

28:22

nanotubes so that they are not hazardous,

28:25

right. And also all

28:28

research I've read has suggested that it's

28:30

not that we shouldn't go into making carbon

28:32

nanotubes. Yeah, yeah, yeah, it's it's most

28:35

people are saying that, yes, it's a danger, but these

28:37

things are so useful that we we almost

28:39

can't afford to to not continue researching

28:42

them. And that most most of the most

28:44

of the danger comes to people who are going to be

28:46

working in development development

28:48

labs creating them. Um And that

28:50

there are definitely lots of different air

28:53

filters and other precautions that could be used

28:55

to to lessen the danger to these

28:58

important workers. Um And

29:00

And that ultimately we may find ways

29:02

of creating these as you know, so safely

29:05

that it becomes a non issue.

29:08

Um. Not that you know, we can ignore it. That's

29:10

the important part is don't ignore the fact that

29:12

there's a danger, but but understand

29:14

that there may be ways of working around

29:16

that so that we minimize the danger to ourselves

29:19

while maximizing the benefit that these things

29:21

could provide us. So, yeah,

29:24

I mean, it's it's you know, one of the things

29:26

that definitely we have to keep

29:28

in mind about technology. I mean, just like your

29:30

computer at home, assuming you have one,

29:33

has some material in it that can be extremely

29:36

toxic if you are if you're exposed to it

29:38

directly. But computers

29:40

are incredible benefit too. It's just that

29:43

it's under specific circumstances that you can

29:45

become very dangerous. Like let's say you catch

29:47

it, it catches on fire, that

29:49

kind of thing, or you're taking it apart to try

29:51

and harvest the various

29:54

uh metals and minerals

29:56

that are inside your computer. That

29:59

would be a bad thing to do. Don't

30:01

do that. So yeah, I

30:03

mean it's just one of those things where you've got to keep in mind

30:06

the various scenarios and uh and

30:08

and remember to to treat it

30:10

carefully. So guys,

30:13

if you're out there playing with carbonano

30:15

tubes, just you know, be careful. Yeah,

30:19

you know, what you do in your spare time. Leave it to

30:21

the professionals. Probably, I think it's

30:23

it's probably the important important thing there. But I

30:26

find this this whole area of study very

30:28

interesting. I mean, it does have the the

30:31

potential to completely revolutionize

30:34

everything that has to do with electronics. I mean you sit

30:36

there and you think about how incredible things are right

30:38

now, go and go to like

30:41

see yes one year and take a look at

30:43

a TV, and you see how thin they've become.

30:46

Well, with this sort of technology, they could be

30:49

even even, you know, so thin that when

30:51

you mounted against a wall, you wouldn't be able to

30:53

see the difference between the wall and the TV. I

30:56

mean, that's that's how thin we're talking basically

30:58

basically a sticker. Just yeah, think.

31:00

I mean, it's gonna take a while before we ever get

31:03

there, so we can at least get to a point where

31:05

it's gonna look like a piece of paper. And

31:07

that wraps up another classic episode of

31:09

tech Stuff. Hope you guys enjoyed it, and

31:12

I look forward to revisiting carbon

31:14

nanotubes. I think it's about time I do an

31:16

update on that particular topic,

31:19

because I guarantee a lot

31:21

has happened since two thousand. But

31:25

if you guys have suggestions for future topics

31:27

of tech stuff beyond carbon nanotubes,

31:30

let me know. Send me an email the addresses

31:33

tech stuff at how stuff works dot

31:35

com, or drop me a line on Facebook or

31:37

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31:39

s W. I look forward to hearing from you, and

31:42

don't forget to visit our website that's text

31:44

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31:46

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31:48

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31:51

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31:53

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31:56

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31:58

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