Nanotechnology Expert Explains One Concept in 5 Levels of Difficulty | WIRED
Hi i'm george celevski. And i'm a research scientist, at ibm, tj watson research center, today, i've been challenged, to teach one concept. And five levels of increasing complexity. And my topic, is nanotechnology. Nanotechnology. Is a study of objects, in the nanoscale. Between, one and a hundred nanometers, in size, and it turns out that objects, in this size scale. Have really interesting, properties, that differ from objects, at a macroscopic. Scale, our task as nanotechnologists. Is to understand, these materials. Understand, their properties. And then try to build new technologies. Based on these properties. At the end of the day, my hope is that you'll understand nanotechnology. At some level. Hi, are you bella, yes, bella i'm george nice to meet you nice to meet you. I'm a research scientist, do you like science. Yeah, i wanted to talk to you about, a specific, type of science called nanotechnology. Have you ever heard of this word before. Nano's kind of a funny word right it's a word that's used before another word, and it means, one billion what's the smallest, object you can think of a baby, ant. A baby and very good so i have over here a meter stick let me show it to you and so that's a meter, and if i divide, it by 1000. I get a millimeter, so milly, just means one thousandth, there's all these little lines on the ruler, and each of those little lines is one millimeter, so baby and is probably a couple of millimeters. So even the thing that's the smallest, thing you can think of it's a million times bigger, than, a nanometer. Tiny tiny tiny, tiny tiny, tiny. If i took this stick. And i was to draw, one, billion, lines. The distance between those two lines would be one nanometer. So that's really all it is it's just a measure of size. But it's really. Really, really tiny, you know smaller, than, anything that we can see, with our with our eyes the reason why. In nanotechnology. We you know in scientists, we care about things that are that small. Is because. There are objects called atoms. Have you ever heard of atoms before, yes. Um i first heard of them on a show i watched, called storybots. They're just little, things, that make up like everything. On earth, even earth. That is a perfect, explanation, but what if i told you that scientists. Invented, a special, type of microscope. That not only lets you see atoms. But also lets you move them around and build things with them would you think that would be pretty cool, yeah, so it's called a scanning, tunneling, microscope. And not only can you see the atoms but you can move them around atoms are kind of sticky, you can actually build things, using this instrument, with actual, individual, atoms. So if i gave you, that machine, would you want to make something would you want to look at something very carefully, i would want to, make. A unicorn. Have the atoms. You are definitely a second grader, my daughter would probably answer the exact same way, a unicorn, would be awesome why do you study. Stuff so, small. I study it because. Objects that are that small. Have really, interesting, properties. They behave, completely. Different. Than objects, that are big. And because of that we can build really cool things with them, like really, fast computers, for example. Or new types of batteries. Or new types of solar cells and a lot of nanotechnology. Is kind of like playing with legos you take these small objects. And you you put them together, to build, something new something interesting that no one's built before, it's like legos, for scientists. Cool. So how old are you i'm 16.. 16., so what is that you're in 10th grade, junior year so 11th grade so have you heard of nanotechnology. Have you heard of this term before yeah i've heard of it what do you think of when you think of nanotechnology. It kind of seems, very science, fiction, you know you're right when you read about some of these technology, it does feel like science fiction, but the part of nanotechnology. I wanted to talk to you about is stuff that you, probably, use. Every day. Most of your day, all of the time can you guess, what, aspect of our technology i want to talk to you about, my phone. Yeah so modern computer chips. Rely heavily on nanotechnology. Does this look familiar to you can you guess what this might be i, don't know. So this is a silicon, wafer, and they're embedded in basically. Almost every object that you use from a laptop to a phone to cars. Television, sets. Appliances. We end up cutting these into little squares. And those repeating patterns each of those is a processor, and those chips are what goes into all of these objects, what i want to talk to you about is how we got from, kind of where we started. And how we're able to actually, fit, 18. Billion. Of these little devices. In a little, you know one inch by one inch, uh area, they're called transistors. It's a switch, very simply think of it as a light switch that turns on and turns off using an electric field by applying a voltage.
I Went through my kids lego, bins to build a very simple model, of a transistor. And these are wired together in circuits, so that you can do computation, you can do logic with them where nanotechnology. Comes into play, the way you double the number of transistors, on a chip can you guess what you would have to do to this transistor, you make it smaller, you have to make it smaller, exactly. But here's the problem so about. Oh 10 to 15 years ago the devices, got so small. That if you shrunk them, this gate that actually turns it on and off loses its ability to control, the channel and so they did was they took devices, like this into these things we call them finfets. Kind of like a fin on a fish. So they're very thin transistors. The width of these fins is only six nanometers. Okay so six nanometers. Is. 25, to 30, atoms, across, and they repeat this over the entire wafer. Just about perfectly, it's just a huge feat in engineering, but these types of devices, are exactly the kind of devices, that your phones and computers, either have or will have in the near future and it's a way that nanotechnology. Is directly, impacting, you right now how do you make stuff that small like obviously. It's not handmade, so is it like factories, and stuff, exactly, so these are made using a technique, called lithography. You basically, cope the silicon wafer, with a polymer, then you put a mask on it and then you shine light through it and the features, of the mask, the size of those holes, determine, the feature, size, in the chip it's not just the size of the mask that matters, it's the wavelength, of the light that's used. We talked about nanotechnology. Being science fiction before but this is real stuff that's being produced that's being made that's being. Used every day by people, in middle school i've built all the like, the little switches where you turn the electricity. On and it goes from like one thing to the other but those are like the really big like comical. Like, plugging, in like legos, and stuff when we saw the picture, of all of the little ones like it's like a city. It's crazy how simple, and complex, it is at the same time exactly, i couldn't put it any better that's right. So what's your major, chemical engineering, what made you choose that like any, freshman going into chemical engineering i was like i like chemistry. So i'm gonna go into chemical engineering. But luckily i also like you know, all the math and all the science too so have you taken a quantum mechanics course, i have i took that last year i think to really get deep into nanomaterials. And nanoscale, devices you really have to understand.
To Some level quantum mechanics, what it teaches us as we make these devices smaller and smaller. Their properties, begin to now depend. On the size, and the orientation. Of these devices. There are materials, and you're taking a 2d materials class you know about this that are intrinsically. Thin like as they're grown as they're fabricated. They're already at the nanoscale, and they possess, these, quantum, confinement, properties, that as a nanotechnologist. You try to exploit, and so the first ones i wanted to talk to you about are quantum dots have you heard of quantum dots before, yes so these are typically. Semiconductors. They can be cadmium, selenide, cadmium, sulfide, zinc cell not and they're small, clusters, of atoms, they can be from, two to 10 nanometers. What's interesting about these materials. Well, the other day we were talking about, the kind of different dimensions, you can have of nano technology so all the way from like 0d, to 3d, if i remember correctly my professor labeled it as 0d. That's correct yeah because, of quantum confinement. Once you get below, this 15 nanometer, range. The band gap of the material. Depends, completely, on the size of the material, so in bulk materials if you want to change the band gap you have to change the material, right but in these quantum dots specifically. Just by changing the size you can change their band gap, and because their band gap is changing their optical, properties, are different and you can precisely. Tune, the wavelength, of light that they emit, just by changing their size what are the applications. Of these quantum, dots, there are people that are exploring, using these materials, for diode lasers, there are companies, that are building displays, from these materials. And there are even people thinking about if i take these quantum dots and i change the chemistry, on the outside, so they stick to specific, types of cells. Or tissue. That i could really do some interesting, imaging and therapeutic, work to track disease, even maybe to treat disease if you can very precisely, control the chemistry, how far away is this from being, actually used on an industrial, level, the optical, applications. Are in development, the science has really been worked out the health stuff, because, of all of the things you have to consider when you're putting something in someone's body, is definitely, further out there for example some of them are made from cadmium, cadmium's, toxic you would never put that in someone's body, but there are other materials.
Like Gold and silver, and titanium, dioxide, which are less toxic, and people are exploring, using those. So have you learned about graphene, yeah do you know what this is carbon nanotube, carbon nanotube, right so if you roll up graphene. Depending, on how you roll it and the angle you roll it with it has, different properties. So if i roll it one way, it'll act like a metal, if i roll it a different way it'll act like a semiconductor. The one that gets everyone most excited. Is that the electrons, and holes move very fast, through through graphene, and so there's a lot of interest in using these for certain types of high speed electronics. The other interesting application, is because, it's, one atom, thin, it's very sensitive, to changes in the environment and so there's a lot of interest in using them as diagnostics. It's on. Us researchers, to find ways, to a control that process, and then be to actually, build. Some sort of interesting, technology, from them so you've been talking about. The different ways you can say roll these nanotubes, so how do you go about, building, and controlling, these nanotubes, in terms of their, diameter, so you're you're speaking my language this is what i spent, many years of my life, working on you don't physically, roll up graphene. You, grow nanotubes. By basically, taking, nanocrystals. And you deposit, them on a surface. And then you do a cvd, process chemical vapor deposition so you basically. Flow in a carbon source. The carbon dissolves in a nanocrystal. And then once the nanocrystal. Is saturated. The nanotubes. Precipitate, out of them in tubes, then you have to develop, ways to go. Into this, pile of nanotubes, and pull out exactly, the ones that you want, so i have to find ways to program, them to go exactly. In the places, that i want i, modify, the surface of the nanotube. With specific, molecules. That recognize. One type of surface, over another, and then i just pattern the surface, and the tubes just land, exactly, where we want them to and it's still very much in the research stage the ultimate goal, is to build, functional, high speed electronics, using these these new materials. In my nano materials, class actually, just a couple days ago we were talking about, different applications.
Of Nanotechnology. And things we know. And we touched on the topic that right now silicon, is kind of down to the smallest level that it can get and so we have scientists, out there researching. Other materials, drilled by silicon, yeah 100, that's right and that's the motivation, for looking at these, emerging materials, but i would never bet against. The, innovation. And the creativity. In this nano electronics, space tens of thousands of scientists. Every time, they hit, a barrier. At least historically. As a guy they have found a way to overcome, it i mean it's a real. Marvel, in ingenuity. So i gotta ask the lights that are behind you is that related to the quantum dots that you work with at all it's just pretty lights. But now that you suggested, it these were inspired. By, the array, of quantum dots that we showed earlier so that's the story i'm going to stick with. I like it well thank you so much this was all so very interesting. So you're a graduate student, and so tell me a bit about your work i'm working on energy storage materials, and, the most popular. Uh our batteries, that we work on a lot of the revolution, that's come in electronics. Is kind of our model to try and use some nanoscale, advances, and put them in, uh to batteries, what is it about, nanomaterials. That scale, and the properties of these materials, that make them, uniquely, promising, to incorporate, into battery technology. So for batteries, one of the main constraints. When we're designing batteries. Is, trying to, maintain. Or reduce, the volume, and mass. Of the components. And nanomaterials. Are, particularly. Well suited to adding functionality. While having this negligible. Increase in volume, so we get a huge, benefit from using nanomaterials. Without sacrificing. The, volume of the battery what is it exactly, that you're trying to tease out of these materials, to improve, the battery's, performance. At first, one of the main things that we did was use nanomaterials. To add conductivity. And so, carbon analysis, and graphene. Are really good at adding conductivity. To batteries, and then in the subsequent, years nanomaterials. Have been really interesting, from things like incorporating. Sensors, into batteries so increasing the functionality, of batteries. Having some. Responsive. Materials, that use, things like graphene, sheets, that are incorporated, into a matrix, and then you add a safety functionality, to a battery, we're trying to squeeze out almost.
All The functionality, that we can and as new nanomaterials. Are being discovered in their new properties, being discovered. A lot of the time that that someone tries to think of a way to translate that into a battery, because the materials, are so small they're at the nano scale. Their properties are dominated by quantum mechanics, which means that, even slight changes, in their size, in their orientation. Get profound, changes in their properties. And while that's, very scientifically. Interesting. And it allows you to tune their properties by making, subtle changes, from a technology, point of view it actually is it's a bit of a headache, in the sense and technology, we want to optimize, for a property, and then repeat that over and over again so what are some of the challenges. That. You face, in the lab related, to working with these materials, and trying to incorporate, them into, uh into the batteries, i think every step of a process in a battery is kind of something where you have to think about, how would this translate. To making a battery, in terms of the production, one thing that i think is very interesting about the field of, nanoscale, materials in general is that how you make the material, changes, the properties, a lot and so if we claim that this 2d material, has this property, then, tying that to the battery performance, is something that's pretty. Difficult, to do it takes a few steps in between so we have to think kind of creatively, with how we can do that that's actually i think a very common problem, we can build a device, in the lab it could be a transistor, can be a battery, and then you ask the question okay so what's the next step how do we take it from that lab demonstration. Into a technology. The kind of work that i'm very interested, in is developing, tools, to. Make. The exact type of materials, that you want the tools that we use in the past for conventional. Fabrication, just don't work with these these materials, because, they're all grown from the bottom up, they're intrinsically, small, and you have to, find ways to either use chemistry, or some other means to. Get them to assemble. Into the structures that you want to actually either grow specifically, what you want or after you grow them to pull out the ones that you want you need to be able to, build that same thing over and over again with the exact same properties. No one. Institution. No one research, lab no one, national, lab, is going to solve all of these problems, on their own because they are difficult, problems. And there is a real, important payoff, at the end, and it's going to take all of us, making our contributions. To push to push these, this field forward. I remember reading your papers when i was a student, and you know we're all trying to, create these materials. And finding ways to exploit, their their properties. What i love and i'm delighted that you're here to talk to us about is how you took inspiration, from nature and sort of recognize, that nature's figure out a way to.
Both Synthesize. Incredibly, complex, nanostructures. With high functionality. And how you sort of were inspired, by that to do the research that you're that you're doing now life gave us this toolkit, that is already on the nanoscale, so we think that that's a great place to think about. Making materials, on the nanoscale. And manipulating. Materials, on the nanoscale, and actually and wiring them together as well this abalone, shell you can see the exquisite, beautiful. Colors and structures, of it this is a nano, composite, material. If you take this and fracture, it and you look at it in a scanning, electron, microscope, what you'll see is it's made out of these beautiful, tablets, and i studied that as a graduate student i looked at that and i said that is completely. Amazing, you have an organism in the ocean, that takes what's in its environment, which is calcium. And carbonate, that's dissolved in the water and templates, it into this really exquisite structure, and so you think that's great calcium, carbonate, is great but what if we wanted to make a solar cell or, a, another electronic, device, or a, a battery, how would you get an organism, to do that and you say okay that's a really crazy idea. But is it really that, crazy, if this abalone. You know already figured out how to do it you know 500, million years ago so we're saying okay. Abalones, build shells, can viruses, build, solar cells can viruses, build. Catalysts, can they build, uh batteries. Using the same, kind of idea, it's really fascinating, work especially now we're all familiar with with viruses, and how they act and i'm not aware of any viruses, that build nanostructures, so i mean how did you come to that and then how do you actually. You know program, a virus, to do your bidding, we work on something called bacteriophages. It's a virus with dna, this particular, bacteriophage. Called m13, bacteriophage. Is made up of single stranded, dna, and proteins. It's long and thin, so it's 880. Nanometers, in length, and it's. About, nine nanometers, in diameter. And so one of the reasons i love it is it spans the nanoscale, and almost the micron scale at the same time take the single strand dna, obviously a model. And you can cut it with molecular. Scissors, and you can put a new piece of dna, in between.
And So you put a small piece of dna in there that doesn't doesn't belong there, and that piece of dna. Is going to, randomly, code for. A protein. Now the, next time that, that, virus, is replicated, within a bacterial, host. It'll be able to put a new, protein, sequence, on the coat just a short protein sequence on the coat, maybe like eight or twelve amino acids in length and just like that avalon is going to grab calcium, and build calcium carbonate we're gonna have our viruses. Build, iron phosphate, for a battery electrode, material, or gallium arsenide, or cad, sulfide. For a semiconductor. Material, so you've, evolved, and, i suppose, trained these viruses, to build the materials that you want them to build by exposing, them to the raw materials. And then you know evolving, their. Their function, we're trying to build electronics, from nanomaterials. The critical issue that we're facing is how do you go from those single experiments, with the single material. Understanding, its properties, how do you scale that to the billions, of devices, that you need in a technology. It is a, you know a chemistry driven approach we're not going to grow them exactly where we want them but to take that one, you know one step and to tie it into what you're doing. It sounds like there could be an area of collaboration. Where, instead of using sort of conventional, chemistry, that we can. Train some of these biological, elements to do that to do that work work for us, biology, is is chemistry, molecules. Proteins, and dna, work with all the same kinds of bonding, and and things that the chemicals that that, you're going to be looking for in these, in these processes. It's put together. Uh in a way, that, when a a protein or enzyme, uh, folds, it almost always folds, correctly, that's kind of the beauty of it the predictable. Aspect, of it encoded, in its dna. If we need to make it the same, over and over again then as long as you have the right dna sequence, dna is a beautiful. Structure, on the nanoscale. And there's really. Really cool incredible, work on dna origami, where dna can fold into just the right right structure, and so i can see that as an interface. That would be really um, cool and interesting, in your work and you can have the virus, make the dna, for the dna origami, and then use dna, to. Assemble, your uh beautiful structures. It's really fascinating, you have all these little worker viruses, building the materials, for you how are you then applying, these materials that you're that you're building, we started thinking about, how can we make an impact, in, cancer, we do it mostly.
In Imaging, technology, to look deep inside, the body non-invasively. With light, and the way that we came about that was through solar cells and batteries, we trained our viruses, to pick up carbon nanotubes. And hold on to them very very tightly, and then we'll we'll give a virus, a second gene, to code for a protein. To grow, in the case of a battery, a battery electrode, material, it allows it to weave together. A good electrical, conductor. And a good ionic conductor, at the same time. All in the within this really really small space. And the optical, properties, of these carbon nanotubes, are in the wavelength. That is interesting for imaging, deep inside the body, we started building a bunch of imaging tools, that could image, um, above a thousand nanometers. Uh, wavelength, and so this is in, near ir's. And that's a really, special. Window, where you have some optical, transparency. Of of tissue in the body, the other gene we engineered to find ovarian, cancer, we developed, imaging tools. With harvard, medical school and mit lincoln labs, to find tiny ovarian tumors, it's hard to see things less than a centimeter, in size. With ovarian, cancer just based on the location. In the body, but with our, imaging system we could find tumors, that were below a millimeter, in size actually, looking ahead, five years ten years. You know where do you see. Your own work and maybe the field more broadly, the future i'd like to see is environmentally. Friendly, chemistry. And materials, synthesis. And i think that we're really, going that way if we think about, batteries of the future, solar cells of the future, uh thinking about, earth abundant materials. And processes. That are compatible, with the earth and. Environment, one of the things i love about about ammo science is it tends to break up the silos, between those traditional. Scientific, disciplines, my training was in chemistry, but i had a very quickly, merged chemistry, in physics. And now i see an area where chemistry physics and biology, are coming together. To produce, new materials, and new technology, into it and to advance the field forward and so being in this field, you kind of have to cross-pollinate. You know between these different disciplines, and kind of advance the field together, i agree, completely, we like to solve problems. Nanobio. Is the toolkit, that we bring a lot it happens to be a very, strong and evolving, toolkit, that's another thing that i love about, biology. Is, if you can. Come up with a solution, that's not perfect, at all to begin with when you're making a battery electric, material, or. Any kind of material you're making. You have, evolution. On your side, to try to make it, better and better. As a function of time, that can be quite rapid so angela thank you so much for joining us and i look forward to seeing, more work coming out of your lab in the in the future, thanks for having me george it was really fun to interact and i'm very excited about our future collaboration, me too. Absolutely. I really enjoy talking to these five different people about nanotechnology. Nanotechnology. Is a field that affects, all of us every day, as it finds its way into a variety of applications. And i hope you enjoyed it as well and see the impact, that nanotechnology. Has on your life today and how much more of an impact it will have on all of our lives in the. Future.
2020-10-10 18:47
