Speaker 1: Get in touch with technology with text stuff from how
Speaker 1: stuff Works dot com. Hey, they're and welcome to text stuff.
Speaker 1: I'm Jonathan Strickland and I'm Laing, And today we wanted
Speaker 1: to talk about something pretty darn cool, nanogenerators. What are nanogenerators, Jonathan? Well,
Speaker 1: you know, in order to understand what a nanogenerator is,
Speaker 1: it helps if we define some terms really quickly, all right,
Speaker 1: because because nano and it clearly means tiny, it means
Speaker 1: it's it's one billion. Yeah, if you talk about nanometer,
Speaker 1: it's a one billionth of a meter yep. So we're
Speaker 1: talking about the nano scale. You're you're saying that stuff
Speaker 1: that exists gently speaking, in between one and a thousand
Speaker 1: nanometers somewhere in there, and usually it's between one and
Speaker 1: five d nanometers. That tends to be the area we
Speaker 1: talked about. Now, the nanoscale is is one order larger
Speaker 1: than the atomic scale, right, So even at the nanoscale,
Speaker 1: atoms are still tiny, but the nano scale is much
Speaker 1: smaller than what we are accustomed to, and we need
Speaker 1: very special equipment to work with stuff and even see
Speaker 1: stuff that's on the nano scale. Right, Yeah, Just to
Speaker 1: give you an idea. Human hair is usually between about
Speaker 1: six micrometers wide, which means that you would have to
Speaker 1: divide a hair at least sixty thousand times lengthwise in
Speaker 1: half in order to make it one one nanometer right exactly.
Speaker 1: Yeah nanometer. Yeah, it takes. It takes very small. It
Speaker 1: takes one tho nanometers to make one micrometer. That will
Speaker 1: become important later on in our conversation. So, yeah, super small.
Speaker 1: Think of the smallest thing. You know, it's smaller than that,
Speaker 1: way small, unless you're thinking of like an atom, in
Speaker 1: which case you went too far, turn around, go back,
Speaker 1: come back. But yeah, So so we're talking the nano scale,
Speaker 1: very tiny stuff, and there's a lot of interest in nanotechnology,
Speaker 1: this idea of being able to create things that work
Speaker 1: on this nanoscale for all sorts of applications, everything from
Speaker 1: actual mechanical applications, biological applications uh and uh, and even
Speaker 1: stuff like you can find nanoparticles and stuff like like sunblock,
Speaker 1: you know, has nanoparticles of zinc in it to help
Speaker 1: block ultra violet radiation. Well, when you talk about building
Speaker 1: things on that nanoscale and you're talking about actual stuff
Speaker 1: that's doing work, it has to get power from somewhere.
Speaker 1: So where do you get power from? If you are
Speaker 1: this tiny? You can't go to a nano gas station
Speaker 1: and fill up with nano fuel as far as I know,
Speaker 1: not that we're personally aware of. Now, So the nanogenerator
Speaker 1: is this this idea of a device that uses stuff
Speaker 1: on the nanoscale in order to generate small amounts of
Speaker 1: electricity by converting energy from one format into electricity. Now,
Speaker 1: remember we cannot create or destroy energy. We can merely
Speaker 1: convert it from one form into another. And in this
Speaker 1: case when nanogenerators, there are a couple of different kinds
Speaker 1: of energy that we can look at to convert into
Speaker 1: electrical energy. The main one is mechanical energy, so through
Speaker 1: piezo electric piezo electric materials. Yeah, so if you've ever
Speaker 1: heard this term, piezo electric or as I sometimes say,
Speaker 1: piezo electric because I'm pretentious, or piezoelectric because pie is delicious.
Speaker 1: Pie has been so long, guys, I'm sorry, Hi, alright,
Speaker 1: So anyway, Yeah, so piezo electric materials, this is this
Speaker 1: is a kind of material that when you apply a
Speaker 1: mechanical stress to it, it essentially emits electricity and the
Speaker 1: reverse is also true if you were to apply an
Speaker 1: electric charge to a piezo electric material, it would then
Speaker 1: move in some way, vibrate in some way. Right, All
Speaker 1: of your quartz watches, for example, contain piezo electric crys crystals. Yeah, yeah, exactly,
Speaker 1: you get this little uh. You apply a very specific
Speaker 1: amount of electricity to this quartz watch, and it vibrates
Speaker 1: in a very specific way. It's it's predictable and it
Speaker 1: will do that every single time. And that's you know
Speaker 1: why they are great for keeping time. So as long
Speaker 1: as you've worked out all the math, it should it
Speaker 1: should keep time very very well, of course, you know,
Speaker 1: until something goes wrong with one of the other mechanisms
Speaker 1: in it. Yeah, and then then it's time to buy
Speaker 1: a new watch. That's how that's what time it is.
Speaker 1: You you still know what time it is, just it's anyway.
Speaker 1: So piece of electric materials very useful when it comes
Speaker 1: to nanogenerators. What you have to do is create something
Speaker 1: that can take a mechanical stress pinching, bending in some way,
Speaker 1: and create a convert that mechanical energy into electrical energy,
Speaker 1: and then you can apply that electrical energy to what
Speaker 1: we call a load in electrical terms electronics, you know,
Speaker 1: you have an electronic load that essentially means it's going
Speaker 1: through some sort of circuit in order to do work
Speaker 1: of some kind. That might be lighting up an LED,
Speaker 1: or it might be helping recharge a battery, or it
Speaker 1: could be powering medical device. But we'll get into the
Speaker 1: applications later on. So that's the main one. And in fact,
Speaker 1: if you go to how stuff works dot com, first
Speaker 1: of all, you're awesome because it's a great website and
Speaker 1: we've got some amazing articles on there. One of those
Speaker 1: amazing articles is how nanogenerators work, and the focus on
Speaker 1: that is the piece of electric nanogenerator. But we'll talk
Speaker 1: about a couple of other types as well in this podcast.
Speaker 1: And Uh, so you've got that, You've got that nano size,
Speaker 1: you know, it's tiny, tiny, tiny, You've got the generator part,
Speaker 1: which is the electricity. Where did this idea come from? Well,
Speaker 1: right down the road, as it turns out, from us. Yeah,
Speaker 1: a lot of the research has been done by doctor
Speaker 1: Zo Lingen of the Georgia Institute of Technology. Yeah, Georgia
Speaker 1: Tech that is the rival school to the college I
Speaker 1: went to. Uh, they are their mascot is the Yellow
Speaker 1: Jackets and we hate them. I go Bulldogs. I went
Speaker 1: to the University of Florida. Oh I hate you too.
Speaker 1: That's tough really imagine there was a there was a
Speaker 1: fullback that I just thought looked exactly like you who
Speaker 1: played for Florida anyway. Yeah, so, Dr John ling Wong
Speaker 1: of Georgia Tech has done a lot of work, a
Speaker 1: lot of amazing research in nano generators, piece of electric
Speaker 1: and other kinds as well. And uh, in fact, it,
Speaker 1: like I said, it's just down the road. So I
Speaker 1: really hope that at some point I will be able
Speaker 1: to visit the Georgia Tech campus and actually maybe speak
Speaker 1: with him, because yeah, the guy has done some phenomenal work.
Speaker 1: There are a lot of papers that are available for
Speaker 1: free online that you can read. Georgia Tech hosts many
Speaker 1: of them, and you can actually read the scientific papers.
Speaker 1: I will go ahead and give you guys a warning.
Speaker 1: They are not meant for They're extremely scientific. Yeah, if
Speaker 1: you're not terribly familiar with with with electrical engineering or physics, uh,
Speaker 1: they can they can get very dense, very quickly, but
Speaker 1: they are uh, you know, the this is the leading
Speaker 1: research in this field. So it's very interesting stuff. We'll
Speaker 1: toss up some lengths on social Yeah, definitely. So let's
Speaker 1: talk specifically about the piezoelectric nanogenerator and what's going on there.
Speaker 1: So they're using they've used lots of different materials to
Speaker 1: try and do this because, uh, there are several different
Speaker 1: kinds of materials that exhibit piezo electric qualities, mostly crystals
Speaker 1: and ceramics of various kinds. Yeah, so you know that
Speaker 1: you've got you've got some choices there to start with.
Speaker 1: How do you narrow that down? Well, one of the
Speaker 1: things that Wonga and his team were looking at were
Speaker 1: stuff that that would not be too brittle, because if
Speaker 1: you're applying a lot of mechanical stress to it and
Speaker 1: you want to have this have a practical application, something
Speaker 1: that's flexible that has some give and doesn't break easily
Speaker 1: would be very useful, Yeah, because otherwise otherwise you really
Speaker 1: get it once and then after that it's like, now
Speaker 1: that was a great generator for one second. Yeah, Yeah,
Speaker 1: And that might be important for some applications, but not
Speaker 1: so much for anything. Uh. And they also wanted to
Speaker 1: find considering that some of the the applications, potential applications
Speaker 1: could be medical and might even require a device to
Speaker 1: be implanted in a person. They wanted to find something
Speaker 1: that would be biocompatible, basically non toxic. You know, the
Speaker 1: goal was sort of less toxic than the stuff that
Speaker 1: goes into the batteries that are already in medical implantable devices. Exactly. Yes, yea,
Speaker 1: So it's that was definitely a goal. And so when
Speaker 1: they were looking into different materials, the one that seemed
Speaker 1: to be the most promising and the one that they've
Speaker 1: done much of their work on is zinc oxide. So
Speaker 1: they ended up creating a nano generator using zinc oxide
Speaker 1: as the basis for it. Now, nano generator has a
Speaker 1: couple of different parts. Uh, nano wires are really important parts.
Speaker 1: Nano wires are these incredibly they're exactly what you would think.
Speaker 1: They're wires that are on the nanoscale. These are measuring
Speaker 1: from about a hundred to three hundred nanometers in diameter. Yeah,
Speaker 1: so if you're if you were to look at a
Speaker 1: cross section of these, first of all, you'd have to
Speaker 1: have like a scanning microscope electron scanning microscope to be
Speaker 1: able to see it. But between a hundred and three
Speaker 1: d nimeters in diameter. If you were to do that
Speaker 1: cross section their length, they are actually much much, much
Speaker 1: much longer longer than they are wide, about a hundred
Speaker 1: microns in length. Yeah. Now remember a micron is one
Speaker 1: thousand nanometers, so you're talking about a hundred thousand nanometers
Speaker 1: in length and a hundred nanometers in diameter. So the
Speaker 1: ratio there is pretty incredible. Yeah. Yeah, but but but
Speaker 1: it's still it's still I mean, the length is still
Speaker 1: only about the same width as two human hairs put together. Yeah,
Speaker 1: if you put two human hair side by side, that's
Speaker 1: how long these wires are. So we're still talking super tiny. Yeah.
Speaker 1: I can't even imagine trying to do research with something
Speaker 1: that's small. Yes, you have to have some very specific
Speaker 1: equipment or incredibly steady hands. I'm amazed. I think it's
Speaker 1: gonna be the equipment thing. Probably, Yeah, I can't imagine
Speaker 1: someone actually, uh sorry I slipped with the Tweezers. We
Speaker 1: lost all our research. So yeah, they took these zinc
Speaker 1: ox side nano wires and they put it on to
Speaker 1: a an etched flexible surface that is called a substrate, which,
Speaker 1: if you are familiar with things like semiconductors, this is
Speaker 1: going to start sounding familiar. Um. And uh. They then
Speaker 1: had some other components that are made from from silicone
Speaker 1: to help with this, uh, to create on an electrode,
Speaker 1: because obviously you need something that's going to collect. Yeah,
Speaker 1: that's gonna act as like a harness to attact like
Speaker 1: the conduit for that electric So you need to have
Speaker 1: something that the electricity can flow through. Otherwise all you're
Speaker 1: doing is generating electric charge that doesn't really go anywhere.
Speaker 1: It will just redistribute to wherever the the electrons can go,
Speaker 1: right yeah, yeah, So you've got kind of a sandwich
Speaker 1: going here. Yeah, and so you've got this zigzag electrode pattern. Uh.
Speaker 1: And when you start to apply pressure to that nanogenerator,
Speaker 1: those nano wires all start to flex. And because of
Speaker 1: that piezo electric nature of zinc oxide, which also acts
Speaker 1: as a conductor, that's another reason why they chose that material.
Speaker 1: When it when they flex, they start to generate that
Speaker 1: electrical charge that that nature of the mechanical energy and
Speaker 1: the electrical energy starts to come into effect. Now the electrode,
Speaker 1: that silicon electrode ends up capturing that charge and it
Speaker 1: carries it through the load the circuit that nanogenerator is
Speaker 1: attached to, and uh, and there might be several electrodes,
Speaker 1: lots and lots and lots of nano wires in a
Speaker 1: millions millions of nana wires. So you're you're talking because
Speaker 1: I mean clearly, if you just had one nano wire
Speaker 1: and one electrode, the amount of electricity you would draw
Speaker 1: off of that would be so tiny as to be
Speaker 1: difficult to put into words. So by collecting all of
Speaker 1: these and putting it all together into a larger form factor,
Speaker 1: you're going to generate more electricity. Uh. The I remember
Speaker 1: reading at least in the early stages, they their efficiency
Speaker 1: of converting mechanical energy into electrical energy was between seventeen
Speaker 1: and thirty percent. So that's a small amount that you're thinking.
Speaker 1: You know, the whole purpose of this is to create
Speaker 1: something that's incredibly sensitive, because you've got on such a
Speaker 1: small scale that even the smallest movement is going to
Speaker 1: create electrics. Something something like a like a heartbeat, or
Speaker 1: the touch of a finger, or even a even a
Speaker 1: not even stiff breeze, a gentle breeze could be activating this.
Speaker 1: The constriction of a blood vessel or even the flow
Speaker 1: of blood through a vessel could be enough to generate
Speaker 1: a significant for this size amount of electricity, and depending
Speaker 1: upon what you you need that electricity for, it may
Speaker 1: be enough to meet all of your needs, or at
Speaker 1: least enough of your needs. So that the battery, because
Speaker 1: I think we're never going to get fully away from batteries,
Speaker 1: but the battery would be more of a backup than
Speaker 1: something to to kind of add in in between or
Speaker 1: in case something doesn't sure. Yeah, the peak that they've recorded,
Speaker 1: according to UM a paper that they published in two
Speaker 1: thousand and twelve was that from a from a one
Speaker 1: centimeter square circuit of this stuff, they recorded a high
Speaker 1: level of thirty seven volt output um, which you know,
Speaker 1: for for comparison to double a battery is what like
Speaker 1: like one point five and a car battery is twelve. So,
Speaker 1: I mean, yeah, it's pretty impressive when you're thinking about
Speaker 1: this tiny scale in lab standards that that's you know,
Speaker 1: a separate thing from real life experience. It's not a
Speaker 1: field tests, right, but it's pretty impressive. Yeah. And here
Speaker 1: here's something directly from one of Wong's papers. He says,
Speaker 1: the coupling of piezo electric and semiconducting properties, and zinc
Speaker 1: oxide creates a strain field and charge separation across the
Speaker 1: nano wire as a result of its bending. The mechanism
Speaker 1: of the power generator relies on the coupling of piece
Speaker 1: of electric and semi conducting properties of zinc oxide, as
Speaker 1: well as the formation of a shot key barrier between
Speaker 1: the metal and zinc oxide contacts. So shot key barriers.
Speaker 1: This is one of those things that I'm not going
Speaker 1: to get into a lot of detail because frankly, it
Speaker 1: goes well beyond my own understanding of electrical engineering and physics.
Speaker 1: But it's essentially a potential barrier, potential being electric electrical potential,
Speaker 1: not not that potentially this could be a barrier to us,
Speaker 1: not like that. Uh. And it's formed at the junction
Speaker 1: of a metal and a semiconductor. So when you get
Speaker 1: to those junctions, that's where you have the shot key barrier.
Speaker 1: And it can act like a diode, which means, if
Speaker 1: you're familiar with electric electronics, a diode h allows current
Speaker 1: to pass through in one direction but prevents it from
Speaker 1: passing through the other way. So that's generally speaking, while
Speaker 1: shot key barriers, it gets way more technical than that,
Speaker 1: and I know that all the people out there who
Speaker 1: are schooled in electronics and and in this kind of
Speaker 1: stuff are probably screaming at me for oversimplifying it to
Speaker 1: that extent. But frankly, uh, I read about it for
Speaker 1: about an hour and watched a full presentation from a
Speaker 1: university in India about it, and that's what I came
Speaker 1: away with. So, because this is not my area of expertise,
Speaker 1: but it is really fascinating And and just to be clear,
Speaker 1: while a lot of our research does follow the work
Speaker 1: that Wong and his team have done, there are other
Speaker 1: teams out there that have also explored the piece of
Speaker 1: electric nanogenerator model, and and some of them are doing
Speaker 1: a slightly different research. There's one team, um, a combination
Speaker 1: of Princeton University and the University of Pennsylvania, McAlpine and
Speaker 1: Pira Hit. Yes. Um, they've been dealing with M. Dirk
Speaker 1: Nate tighten ate. Is that lead? Lead? I have no
Speaker 1: idea what it is. You know what that is? Well,
Speaker 1: you know, it's stuff. It's stuff. It's a it's a
Speaker 1: it's a piece of electric stuff. Yeah. They also are
Speaker 1: creating a nano ribbons. All right, Well, it's this this
Speaker 1: PCT is extremely brittle, and they figured out a way
Speaker 1: that when it's a specifically shaped it can stretch up
Speaker 1: to ten percent without breaking and uh and therefore be useful. Right,
Speaker 1: And and these nano ribbons are that shape that they
Speaker 1: have come up with. That, Yeah, because usually this is
Speaker 1: that they're using a material that that traditionally you would
Speaker 1: not think would be very useful because it's very brittle,
Speaker 1: But because they have shaped it in this way, it
Speaker 1: could actually work in this piece of electric nanogenerator format
Speaker 1: because it doesn't break immediately upon use. All Right, They
Speaker 1: fix these nano ribbons to UM to stretched silicone rubber
Speaker 1: surfaces UM, and when those surfaces are relaxed, it creates
Speaker 1: a buckle in the nano ribbons, a bend in the
Speaker 1: nano ribbons without actually breaking them. And uh then then
Speaker 1: in their bent state, any movement within them generates electricity. Yeah,
Speaker 1: it's pretty awesome. I mean, these are really creative ways
Speaker 1: of designing these sort of tiny, tiny generators. Now, those
Speaker 1: are the that's the main kind of nanogenerator we talk
Speaker 1: about in the article on how stuff works. But like
Speaker 1: I said earlier, there are a couple of other methods
Speaker 1: and we're going to talk about those in just a minute,
Speaker 1: but before we do, let's take a quick moment to
Speaker 1: thank our sponsors. All right, and we're back. So we've
Speaker 1: got the piece of electric stuff down. We're experts, we
Speaker 1: know all about it. Yeah, yeah we can. You can
Speaker 1: ask us anything and we will him and haw. But
Speaker 1: but we'll pretend like we know we will. We will
Speaker 1: look it up on the internet. Real good. It's super
Speaker 1: fascinating stuff. And I am familiar with piece of electricity
Speaker 1: or I shouldn't say piece electricity, but piece of electric materials.
Speaker 1: But this was this was at a level of detail
Speaker 1: that would beyond anything I had read before. But like
Speaker 1: we said, that's not the only only way. There's also
Speaker 1: a kind of nanogenerator. And again Wong has done a
Speaker 1: lot of research in all of these called triboelectric generators.
Speaker 1: And uh, this is this is basically static electricity. Yeah,
Speaker 1: that's that's it's friction based, right exactly. So there's still
Speaker 1: a mechanical element to it, but it's not the mechanical
Speaker 1: stress that is converted into electricity. It's rather that the
Speaker 1: act of friction ends up generating this electric charge that
Speaker 1: is then harnessed to go into a circuit. Right. It's
Speaker 1: that it's the fact that some materials can can gain
Speaker 1: or lose or tend to gain or lose electrons upon
Speaker 1: contact with other materials. Yeah, so you have to use
Speaker 1: two different kinds of generally speaking plastic materials and rub
Speaker 1: those against each other. Uh. They found that if you
Speaker 1: use two of the same type, you would not get
Speaker 1: the kind of right. And and you know, and you can.
Speaker 1: I'm sure that everyone here has tested this, uh, you
Speaker 1: know in an annoying or hazardous way in terms of
Speaker 1: you know, they're delivering a small shock to a sibling
Speaker 1: by rubbing your feet on the carpet and going over
Speaker 1: and poking them, or the rubbing of the balloon against
Speaker 1: the hair, right, right, Yeah, or or even something something
Speaker 1: more unfortunate and dangerous like uh, if you're if you're
Speaker 1: dealing with computers with with computer enters, right, and you
Speaker 1: haven't grounded your having grounded yourself, and you know it's
Speaker 1: my Faraday cages are really really cool. It's it's also
Speaker 1: why if you ever decided to build your own computer
Speaker 1: and you're doing it from scratch and you're getting ready
Speaker 1: to put that microprocessor into the motherboard, ground yourself first, please,
Speaker 1: because otherwise that that lovely stuff that's saying in front
Speaker 1: of you maybe rendered useless with one unfortunate zap. Important
Speaker 1: safety tip, thanks Sagon. Yeah, you're welcome. Tell him about
Speaker 1: the twinkie. So the tribal electric generators, they they harness
Speaker 1: this stack electricity essentially, but they to to maximize it.
Speaker 1: Wong and his team discovered something interesting. They found that
Speaker 1: if you took the these two different kinds of essentially
Speaker 1: plastic materials polymers, these polymers, and if you were to
Speaker 1: put on the sides that are rubbing against each other,
Speaker 1: if you were to put little tiny pyramids, that would
Speaker 1: actually maximize the electric field that you would generate, and
Speaker 1: so it would become more efficient. Otherwise, if it was smooth,
Speaker 1: it would still work, it just wouldn't generate as much.
Speaker 1: But yeah, having the greater surface area. Yeah, so they
Speaker 1: were actually using uh, all right, let's see if I
Speaker 1: can do this, because I I even wrote out how
Speaker 1: I was supposed to say this very long word, so
Speaker 1: this could be disaster, folks, strap yourselves in. But they
Speaker 1: used a sheet of polyester. So that's not the long one.
Speaker 1: That's the easy one. So they went back into the seventies.
Speaker 1: Very concerned, I went back into the seventies, took some
Speaker 1: poor guy's suit and just ripped it off of them
Speaker 1: and brought it back up here. And then they also
Speaker 1: used a sheet of polydimethyl salo sane p d MS.
Speaker 1: Sounds great to me. Yeah. So they use these two
Speaker 1: to rub against each other, and the polyester tends to
Speaker 1: donate electrons and the PDMS tends to accept electrons. And
Speaker 1: so while you're rubbing the surfaces together, they then you
Speaker 1: then the next step is to mechanically separate them, right,
Speaker 1: because because one one surface during this rubbing process become
Speaker 1: has gained a positive net charge and the other has
Speaker 1: gained a positive negative. Yes, yes, but it was a
Speaker 1: lot of it, so and we don't want to be
Speaker 1: too negative on the show. But yeah, yeah, exactly, you
Speaker 1: rub them together and then you mechanically separate them very quickly.
Speaker 1: And uh while the that that's what generates the electric charges.
Speaker 1: You can then the current flows through the gap in
Speaker 1: between them when once they have been separated. Yeah, yeah,
Speaker 1: so you do that, You've got the the electricity moving
Speaker 1: through the load the same way the piezo electric one would.
Speaker 1: I mean, from this point forward, it's exactly the same
Speaker 1: as piezo electric because you're you're just harnessing electricity, but
Speaker 1: the generation is different. It's not that mechanical stress. It's
Speaker 1: the friction, which is a subtle but important difference. And
Speaker 1: uh so, yeah, Wong pointed out said the smooth surfaces
Speaker 1: rubbing together generated a charge, but using those micro pattern
Speaker 1: surfaces it increased the efficiency quite a bit um and
Speaker 1: said that they were generating as much as eighteen vaults
Speaker 1: at about point one three microamps per square centimeter, which
Speaker 1: is very promising. So another potential use of nanomaterials to
Speaker 1: generate electricity. The peak that they found that that I
Speaker 1: was reading in that in that one paper that I
Speaker 1: mentioned earlier, was that up to a vaults. Yeah, so
Speaker 1: for for for a two square centimeter, right, yeah, so
Speaker 1: they what they've done is they have dramatically increased the
Speaker 1: efficiency since they first started looking into this. That's the
Speaker 1: other interesting thing I find about the research these guys
Speaker 1: are doing is that they're not just sitting on their
Speaker 1: laurels after they discover this and go with that. They're
Speaker 1: exactly evolving that elect that that technique. Uh and it's
Speaker 1: it's really exciting stuff now there's another way of generating
Speaker 1: electricity on the nano scale with a nanogenerator, and there's
Speaker 1: probably more as well, but these are the that we've
Speaker 1: read about anyway, and the third is pyroelectric. Right, So
Speaker 1: you have to get a member of the Brotherhood of
Speaker 1: Evil Mutants who is on the nano scale and then
Speaker 1: he just rides a bicycle really fast. That's that's pyro right. Okay,
Speaker 1: this is one of those moments where Lawrence looking at
Speaker 1: me and our listeners have pointed these out, like, okay, no,
Speaker 1: pyroelectric is obviously it deals with heat, and it deals
Speaker 1: with changing temperatures. Although the material itself does not have
Speaker 1: to have uh heat differentials across it, but it does
Speaker 1: have to have some changes in temperature from one to
Speaker 1: another for this to work. Um. And it was a
Speaker 1: team of scientists who had developed a portable nanogener rader
Speaker 1: that's capable of partially charging a lithium ion battery using
Speaker 1: ambient energy as a power source. That ambient energy being temperature.
Speaker 1: He keep or we should say temperature, but because he's
Speaker 1: talking about the flow of temperature. But we apologized all
Speaker 1: about heat and temperature in a previous episode. Go and
Speaker 1: listen to refrigerators. I believe in refrigerators. Yeah. And so
Speaker 1: the team of scientists included uh see Hong Wong, yeah,
Speaker 1: Yong Yan Chong and John ln Wong. Uh. And they
Speaker 1: called the device PEG pe n G. So if Chris
Speaker 1: were here, he would demand to say it's the device
Speaker 1: they called PEG as opposed to the device that goes
Speaker 1: ping um. And it stands for pe m G stands
Speaker 1: for pyro electric nanogenerator. So there's a there's an exciting fact.
Speaker 1: But so what they're doing is they're they're harnessing this
Speaker 1: pyro electric effect, which, if you're being really lead general,
Speaker 1: it means it's small changes in temperature have an electrical potential,
Speaker 1: and the nanogenerator harvests the unused potential energy from its
Speaker 1: surroundings and then puts it to work just like the
Speaker 1: other two. You know, once you've harvested the electrons, then
Speaker 1: it follows the same pathway as piece of electric and
Speaker 1: the tribo electric. Right right, We we honestly understand uh,
Speaker 1: comparatively less about this method. Yeah, it takes a little
Speaker 1: bit more technically complicated. This this one gets, this one
Speaker 1: gets so complex as to be very intimidating. But I
Speaker 1: can tell you there are two different pyroelectric effects. There's
Speaker 1: one that we call the primary effect and one we
Speaker 1: call the secondary effect. The primary effect is essentially that
Speaker 1: the change in temperature results in the electric dipole uh
Speaker 1: wobbling around, moving around at a greater oscillation magnitude around
Speaker 1: equilibrium axis. And you know that sounds really confusing, but
Speaker 1: to go into too much detail would make it even
Speaker 1: more confusing because I can't it illustrated in any way
Speaker 1: in an audio podcast. But essentially it ends up creating
Speaker 1: a flow of electrons due to decreased induced charges and electrodes. Now,
Speaker 1: the secondary effect is way easier for me to understand
Speaker 1: because it's really just going back to piezo electric. The
Speaker 1: secondary pyro electric effect is all about thermal deformation, which
Speaker 1: is the idea that materials expanding contract depending upon the
Speaker 1: presence or absence of h or the flow of heat. Right,
Speaker 1: So if I you know, it's just the same thing
Speaker 1: that you see on a hot summer day when the
Speaker 1: power lines are sagging. You know, everything's expanding in the heat,
Speaker 1: and on a cold day those same power lines can
Speaker 1: be very taught U same sort of thing, Um, that
Speaker 1: deformation on the nanoscale is enough to change the nano
Speaker 1: wires so that you get that piece of electric effect.
Speaker 1: So it's still kind of piezo electric, but it's all
Speaker 1: based on a temperature changes, not the movement. So yeah,
Speaker 1: so again you're it's getting back to that mechanical stress.
Speaker 1: But the mechanical stress is caused by temperature changes as
Speaker 1: opposed to pressure or whatever. So once I got to
Speaker 1: that point, like, I like the secondary effect pyroelectric effect
Speaker 1: way better because I can get it, I grasp it. Uh.
Speaker 1: And so now now let's talk about some of the
Speaker 1: applications for this stuff. So we're talking about these tiny, tiny,
Speaker 1: tiny electricity generators. What would that be good for We
Speaker 1: kind of touched on a couple already. Yeah, we we
Speaker 1: already mentioned medical devices in uh in anything that you
Speaker 1: need to implant that needs to run on a battery,
Speaker 1: for example, uh, you know, a heart monitor or write,
Speaker 1: anything that would require maybe like an insulin. Yeah, so
Speaker 1: essentially what you're you know, anything that you could think
Speaker 1: of that would be an implant that would normally require
Speaker 1: electricity from a battery. Just imagine that you have as
Speaker 1: part of the surgical process that implants this this uh,
Speaker 1: this device into you. You have this nano generator film
Speaker 1: that's also part of it, and that film is just
Speaker 1: all it's doing is taking energy that's being given off
Speaker 1: by your heartbeat and that and converting the into electricity
Speaker 1: that powers the implant. Or it's the power of your
Speaker 1: breathing or the blood flowing through your veins, or the
Speaker 1: constriction of blood vessels, or any of the million tiny
Speaker 1: movements that your body is continually doing anyway. Yeah, and
Speaker 1: it's usually anything that's involuntary because you're gonna be doing
Speaker 1: that no matter why. Because we had to tap your
Speaker 1: finger against your thumb head a million times a day,
Speaker 1: that would get a little bit tiresome, Right, what are
Speaker 1: you doing staying alive? Yeah, It's just like if you
Speaker 1: had to concentrate to make your heartbeat, or had to
Speaker 1: concentrate to breathe, that would not that would not that
Speaker 1: would that would defeat the purpose of the exercise. I'd
Speaker 1: be leading an even less productive life because I could
Speaker 1: be concentrated too much. But that's that's one potential use
Speaker 1: of this. And again because of the zinc oxide, that's
Speaker 1: something that could actually happen as the material does not
Speaker 1: react to the body in a negative way unless you have,
Speaker 1: you know, some sort of allergy to the material itself,
Speaker 1: which is still possible. Um. Also, I mean we we
Speaker 1: could get little little films of this stuff and use
Speaker 1: it to, for example, help power our cell phones and
Speaker 1: other mobile devices. Yeah, just imagine this stuff incorporated in
Speaker 1: your clothing. So let's say that, you know, because you know,
Speaker 1: I put a put a shirt on, and the shirt
Speaker 1: actually has within, you know, sewn into the fabric, one
Speaker 1: of these nanogenerators, and every time I'm moving around, I'm
Speaker 1: actually generating electricity, and maybe that's attached to a little
Speaker 1: battery pack, and then I can recharge my cell phone
Speaker 1: a little a little output plug in your hoodie that
Speaker 1: just goes straight to your cell phone. And we could
Speaker 1: eventually have fully incorporated electronics that are getting powered this way,
Speaker 1: whether they are part of our clothing or something else
Speaker 1: like I could. I could easily imagine that. I mean,
Speaker 1: if you've ever seen anything like fabric displays or where
Speaker 1: double computers, this is the kind of stuff that would
Speaker 1: allow us to power those devices without having to carry
Speaker 1: a big, old heavy battery, which is one of the
Speaker 1: There there are several barriers to the wearable computer model
Speaker 1: right now. That's a big one is that no one
Speaker 1: wants to have to carry it, you know, four pound
Speaker 1: battery because I mean, electronics are such that your laptop
Speaker 1: can be extremely lightweight, but the battery is always the killer. Yeah,
Speaker 1: and it in your laptop requires quite a bit of power,
Speaker 1: whereas some of these other devices, uh, you know, everyone
Speaker 1: wants the super sleek, sexy phone, right. That means you
Speaker 1: have to have a very small battery in there. You
Speaker 1: have to make the device itself as efficient as possible,
Speaker 1: so that it's very very careful about consuming power. Because
Speaker 1: our battery technology has only extended so far, and and
Speaker 1: we have not seen huge leaps in battery capacity. You
Speaker 1: know that it has improved over time, but not at
Speaker 1: the same rate as are improving in microprocessors for example,
Speaker 1: right right, And it's and it's wonderful that they're rechargeable,
Speaker 1: that we have such terrific rechargeable batteries these days. However,
Speaker 1: if we could get something that is continually getting power
Speaker 1: from just moving around, yeah, and again, it could be again,
Speaker 1: it could be harnessing the power of your breathing if
Speaker 1: it's on your shirt, you know, so there you are breathing,
Speaker 1: and the nanogenerators are so small that those even if
Speaker 1: even if you think you're barely moving, it's enough to
Speaker 1: generate electricity. It's just pretty awesome. Yeah, yeah, you could.
Speaker 1: I could also see these being used in uh, in
Speaker 1: other ways as well, Like can you imagine something that
Speaker 1: is kind of like nano sized wind turbines, not so
Speaker 1: much that they're actually turning, but you put them out
Speaker 1: in places connected to stuff where if it's a windy area,
Speaker 1: then every single time of breeze blows by your generating electricity. Right.
Speaker 1: If you could coat the side of a house and
Speaker 1: this stuff, then it could hypothetically power the house. Yeah,
Speaker 1: or at least offset the needs that you have already. Right, Right,
Speaker 1: if you put this in a roadway or on a
Speaker 1: sidewalk and collected the motion of cars and steps going by, yep, yep, yeah,
Speaker 1: every time, every time anyone would walk on it, put
Speaker 1: pressure on it, that would actually help generate electricity. These
Speaker 1: are ways where if we are able to to make
Speaker 1: it efficient enough and robust enough, because obviously, when you're
Speaker 1: talking about something like sidewalks or roads, it will have
Speaker 1: to withstand a lot of punishment and most most of these,
Speaker 1: most of these devices probably couldn't do that yet. They
Speaker 1: they're more like, oh, you can use it about a
Speaker 1: hundred thousand times and to be fine. Well, clearly, if
Speaker 1: it's on a road and that road gets a lot
Speaker 1: of traffic, hundred thousand goes by pretty quickly, right yeah. Yeah.
Speaker 1: As of I mean, these these things are in testing.
Speaker 1: As of early two thousand eight, the East Japan Railway
Speaker 1: Company installed pies electric pads in piece Electric sorry and
Speaker 1: uh in one of the ticket gates and station in
Speaker 1: Tokyo and um uh, you know, trying to figure out
Speaker 1: ways to make trains more energy efficient and and had
Speaker 1: reasonable success. This is really cool stuff because again, if
Speaker 1: it can offset our need for fossil fuels, then that
Speaker 1: is a big benefit environmentally speaking, assuming of course, that
Speaker 1: the production of the nanogenerators is an environmentally friendly production process,
Speaker 1: you know, which actually I have read zero research about.
Speaker 1: That is absolutely a thing to watch out for, especially
Speaker 1: since they're talking about it in the testing phase. They're
Speaker 1: not there's no production, so it's really hard to say.
Speaker 1: But I mean, obviously if the production of the electricity
Speaker 1: would be very clean, but the production of the actual
Speaker 1: devices that generate the electricity could be very dangerous. We
Speaker 1: I honestly don't know one way or the other, but
Speaker 1: that's something you always have to take into consideration. That's
Speaker 1: why I'm always careful when I talk about clean energy.
Speaker 1: You have to look at the big, big, big picture.
Speaker 1: You can't just look at how the electricity was generated.
Speaker 1: You have to go beyond that. For example, in photovoltaics,
Speaker 1: when some of the materials used to make those solar
Speaker 1: power cells are very toxic, or the involved very expensive,
Speaker 1: very earth minerals, things like that. Yeah, Yeah, it's one
Speaker 1: of those things that you have to take into consideration.
Speaker 1: You have to look at the big picture, because if
Speaker 1: you don't, then you're going to have other problems come
Speaker 1: up down the line. So I always recommend everybody when
Speaker 1: you when you look into these things, do try and
Speaker 1: go beyond just the story and see what's what's just
Speaker 1: outside on the perimeter, because sometimes that will give you
Speaker 1: enough information to say, well, this is really cool technology,
Speaker 1: and I think we should pursue it because who knows
Speaker 1: what we could learn. But ultimately I don't see it
Speaker 1: being practical because of x Y and z uh and
Speaker 1: x Y and z might just be because look at
Speaker 1: politics just in general, that is that is always an
Speaker 1: issue as well. I say this as I watch the
Speaker 1: United States totally cut the space program to shreds. But hey,
Speaker 1: you know, I'm not going to talk about that because
Speaker 1: it makes me cry. Anyway, that's probably a whole another
Speaker 1: episode of a whole another episode. We just did episodes
Speaker 1: about space travel anyway. So and we've done some pretty
Speaker 1: awesome stuff, and I'm sure we will do awesome stuff again.
Speaker 1: It's just this will be a little lull, that's all,
Speaker 1: all right, eyes Well, anyway, enough of that commentary. Yeah,
Speaker 1: and that super positive note. Uh And like I said,
Speaker 1: you know that these are super cool discoveries that these
Speaker 1: guys are making. And uh, and I'm really looking forward
Speaker 1: to learning more about it and seeing how it it
Speaker 1: plays out, especially when we start getting into even greater
Speaker 1: detail about how nanotechnology can change our lives. We've just
Speaker 1: scratched the surface. I have a feeling that twenty years
Speaker 1: from now, we'll all be laughing at how limited our
Speaker 1: scope was when we were thinking about nanotechnology, right right. Uh.
Speaker 1: Dr Long is talking about in the next five years
Speaker 1: these being commercial products. That's phenomenal. I mean five years.
Speaker 1: That's no time at all, you know, it's it's definitely
Speaker 1: not the standard scientific response of twenty to thirty years, right, yeah, exactly.
Speaker 1: So guys, uh, this was a great topic. I really
Speaker 1: had a lot of fun with it. So if you
Speaker 1: have any episode ideas, you you know, think this would
Speaker 1: be a fantastic thing for them to talk about, let
Speaker 1: us know. Get in touch with us. We have an
Speaker 1: email address that you can write to. That email address
Speaker 1: is tech stuff at Discovery dot com. Or get in
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