字幕列表 影片播放 列印英文字幕 CHRIS: Hi, everyone. Thanks for coming. My name's Chris [? Wallen. ?] I'm an engineer here at Google on the Maps team. And I'm hosting today Walter Voit and Srishti Goel from Adaptive 3D Technologies, and they're going to give a talk about what they call their extreme 3D printing. So without further ado, I present Walter Voit. WALTER VOIT: Thanks, Chris. It's a pleasure to be back here at Google. As Chris mentioned, I'm Walter Voit. We founded Adaptive 3D about two years ago as a spin-out from a company that I founded back in grad school called Syzygy Memory Plastics. In my spare time, I'm a professor at UT Dallas and run a research lab that focuses in polymer chemistry, in flexible electronics, in radiation processing and materials, and looking at fundamental interfaces of materials. And in this quest to make better, stretchier, lighter, stronger materials, we've come up with some really neat ways to be able to build them layer by layer and make stronger, tougher, 3D printed parts. Let's get right into it. So Adaptive started in 2014. Up here is our management team. I'm the president for now until we find sort of a seasoned management team, for which we're looking. Srishti, who's here, just joined the team a little while ago. She got her Material Science degree at Columbia, and is leading a lot of interactions with the companies that we work with. Dr. Lund is an organic chemist by training who specializes in a lot of our new synthetic monomers. Dan Patterson is our first investor. He's a seasoned private equity guy back in Dallas. He's bought and sold more than 30 companies since 1993 and does a lot in the middle market manufacturing and business logistics, and I think has really come in and given us a lot of experience. He was a Harvard MBA guy from the late '70s. And finally, Brent Duncan. He was the co-founder with me of Syzygy Memory Plastics. He and I were grad school buddies from Georgia Tech. He was in the MBA program and I was in the PhD Program. Brent also has a PhD in Material Science and Engineering from Duke University, and spent some time with a nicotine s startup company in the Research Triangle. And then has been working with a lot of technology transfer back in Dallas for the better part of the last half decade. So what our mission and what our job at Adaptive is, is to really provide services to large companies. We work primarily with large Fortune 500 companies. Halliburton is our first big, big customer. We've also engage a number of others. And we're trying to build parts that can't be made today by conventional means. So let me get into what that market opportunity is. In the past almost 25 years, 3D printing-- you guys have probably heard it as a buzz word, as a tech word-- and it means a lot of different things to a lot of different people. You can 3D print metals, ceramics, plastics, so we're a niche. We're just focused on plastics, and within the area of plastics, we've focused on soft, rubber-like materials, and viscoelastic materials, materials that have extreme toughness. 3D printing has had a 25% compounding annual growth rate over the last 25 years or so, and it's projected to serve as a critical part of the $16 trillion manufacturing economy by 2030. And you have to ask why that is. Well, a lot of the big companies in our space, in the polymer space, 3D Systems and Stratasys are two of the large players. And I think a lot of market hype sort of caught up and even surpassed the expec-- or surpassed the reality of where 3D printing was. If you look at a lot of these stock prices, in 2014 there were some pretty big peaks, and things haven't been so rosy on the market side for 3D printers. And the reason is because companies have been unable to 3D print high value industrial parts. A lot of 3D printers and 3D printing companies, we like to call the Kickstarter babies, have come out with the shock and awe. The hey, let's print something really quickly, or let's print some really complex widgets. But a lot of the back end market reporting from Wohlers and from other sources has identified this giant additive manufacturing market as the real value add. It's the idea that you can print materials. That if you print this first layer, the second layer, the third layer, the fourth layer, they need to be as strong in this x-direction or this y-direction as they are in this z-direction. And a lot of parts suffer from this problem called anisotropy, not the same in all directions. And so with our background in understanding polymers and polymer physics, we've focused on printing isotropically tough parts, and have found really neat ways to chemically cross-link plastics in this direction, as well as in this direction to make them strong and tough. And in a little bit I'll show some of the materials properties, some of the stress strain curves. I don't get too nerdy and techie, but that's sort of the limiting problem that's kept these kinds of materials from being a solution to industrial problems. Today, a lot of 3D printed parts are used to print molds, to print jigs, and then you'll do conventional manufacturing in those 3D printed molds. But it's difficult to print a rubber, to print a plastic, and have that go into an automobile, have that go into an oil well, have that go into a tennis shoe, have that go into a spaceship. And so, what we're looking at doing is solving that problem for a subset of materials. So today less than 29% of 3D printed parts are used for functional parts, and the market is just a fraction of what it could become. So what have we done over at Adaptive to print these tough, high quality rubbers and plastics? Well, we've focused on very scalable solutions. So while we are synthetic, organic chemists at root, we've tried to limit the design and manufacture of brand new monomers. But we use things that we can source from large chemical manufacturers that can be scaled to meet a large market. We've developed a very nice patent portfolio. A lot of the research has been translated from research at the University of Texas at Dallas. But we've been able to build materials with incredible strain capacity, things that can stretch five times their original size and then snap back into shape. Or things today that have a toughness of 16 megajoules per meter cubed, and some experimental materials that are far greater than that. And I'll get more into those details in a little bit. We also tune a lot of the important properties for 3D printed parts. We've developed a new kind of 3D printer to make our polymers, following a process called SLA or stereo lithography. But we've used Texas Instruments DLP projectors. You might have seen the ads, it's the little mirrors, little girls with elephants running around. Maybe you've got home theater projectors. I don't know if this is a DLP projector, but it probably is. But what we can do is we can focus light. These mirrors will actuate at about 6,000 Hz, and so we can turn light on and off very controllably, very selectively, and we designed resins that can be selectively photopolymerized. And we can very rapidly print layer after layer, and print a whole layer at once at the resolution of SLA technology. So most of these mirrors are spaced out about 16 microns apart in one of the machines by the time you have your throw angle down onto a part. It's a little larger than that, so in x and y we've got feature sizes in the 20 to 75 micron range. And then in the z-axis we can make that as finely resolute as we'd like, or as large as we'd like. And that dictates a lot of the print speed of our parts. We've come up with some really interesting post-processing techniques. A part of our process involved only partially curing this layer, so that when the next layer comes on, we get this full chemical covalent cure. And so we've got some very interesting post-processing steps that help solidify these properties. But at the end of the day, instead of providing materials, or providing printers, we're really working with large companies to provide solutions to underlying problems. So for instance, with Halliburton, they've got some needs for very specific geometries in their downhole completions team. So they need plastic parts that can essentially help keep wells open or help close up wells. We need parts that have a high strain capacity, but have a high toughness, and have to be in pretty complex shapes. And so those are the kinds of things that we like to tackle. So what we can do is we can replace polymers where you'd normally use rubbers, nylons, for a host of different markets that you see pictured here. And by controlling the monomer concentration, some of the processing characteristics, and a host of the additives, we've got a huge range. As you can see up here in the little profile, we've got a lot of different parts that I'll play around with. One of the things that we spend a lot of time on is we play with internal structure in 3D printed parts. So here you'll see six little wafers of the exact same material, but the effective stiffness of these materials ranges dramatically. So here's something that's fairly stiff, but it's also not very dense. It's got near the stiffness of a solid part, but because of how this lattice structure is created, a lot of the stresses are translated linearly through the part, and so we've got a very stiff material. We've got other ones that have the exact same density, but by having different internal geometries, we have a huge range in the effective stiffness of these parts. So by being able to selectively control internal geometries during this 3D printing, we can do a lot of things with the same material. And then by changing materials, we've got a huge parameter space to play with. Here's some little Androids we printed for you guys just for today. They also have little microchips that are embedded in their heads, so you can download a little TagWriter app and scan over them and they'll say something fun to you guys, if you want to come try it out a little bit later. Here's some dragons that we've also printed. And so you can get a sense of some of the feature sizes that we get. These belong to a class of materials that we've done a lot of research in the lab, which are close to materials called shape memory polymers. So these happen to be materials called viscoelastomers, or they're materials that are in this transition state. So you can see that when I deform this dragon's wings, they're sort of slowly starting to recover. Well what we can do and what our lab back at UT Dallas focuses on, is these materials called shape memory polymers. Here's a little business card made out of one of the shape memory polymers. But it's a material this is stiff and glassy at room temperature. It has a modulus of 2 gigapascals, so it's just like Plexiglas. Now if I heat this up in my hand, and get it to room temperature-- or get it from room temperature, sorry-- to body temperature, what it's going to do, is it's going to get orders of magnitude less stiff. So what I can do is I can bend this into some sort of metastable shape, and then as soon as it cools off, it's going to get very hard again in this new shape. So a lot of plastics do this. If you've ever as a kid played with liquid nitrogen, you can stick a banana in it and you can hammer a nail into a wall. Or you can dunk a racquetball and hurl it against the wall and it's going to shatter. Or you could dip roses in liquid nitrogen and then they just crumble apart. Well we can design materials that undergo that same sort of brittle to ductile transition, but instead of over hundreds of degrees they can do it over five degrees. And so what we do is we park these materials right at the onset of one of these transitions, and then when that temperature increases a little bit, they get really, really soft. So here are two very similar materials, but this is one where that glass transition temperature, as it's called, is just a little bit closer to room temperature. So as soon as I put this in my hand, it's just going to sort of soften immediately. And so it's going to go from Plexiglas to silicone rubber. And I can bend it, I can manipulate it, but then it holds this new shape very, very well. So a lot of this engineering we've done in designing these shape memory polymers is similar to the problems that we face in the 3D printing world. What we're trying to do is engineer cross-links, engineer these multimonomer solutions, engineer the sterics of side chains. So basically, how these little groups hanging off of our main chain polymers interact with each other to make things stronger, to make them stiffer, to make them tougher, to make them less brittle. And so a lot of that engineering has gone into the materials that we've developed at Adaptive. So what's the real market need? This is a snapshot straight from Stratasys's website. Stratasys is one of the large 3D printing plastics companies in the country. And you can see in the upper right corner of that chart they're missing a whole swathe of materials. So they've got an FDM set of technologies, that's on the left, that stands for fused deposition modeling. That's sort of if you'd imagine taking a hot glue gun and squirting it out and building a pattern, and then putting another layer on, and putting another layer on, you can build materials quickly. Their PolyJet process lays down an unpolymerized resin and follows behind with a laser, or with a UV light, and sort of spot cures it. So our technology is a lot more similar to their PolyJet technology, where we're curing something directly out of a resin. And the materials properties we get are up there close to nylons, close to some of these very high performance materials that 3D printing has had a tough time making in complex, arbitrary shapes. So let's get into a few more technical specifics. Here's a host of non 3D printed materials and what their mechanical properties look like. So if you look on the left, that axis is the tensile stress. That's basically how much force it takes to deform a material. And it's proportional to the cross-sectional area of that material. PMMA is Plexiglas, that's like this material. So it's a fairly strong but very brittle material. If you look at something like low density polyethylene, high density polyethylene, polypropylene, they're materials with a lot of give, with a high strain capacity, but their strength isn't quite as high. And then you've got materials like PA6. That's a polyamide, or a nylon base material. And those combined have a really high strength with high strain capacity. And for us, the figure of merit-- and I think for a lot of 3D printers-- the figure of merit should be the toughness. And the toughness is the integrated area underneath that stress strain curve. And that explains how much energy a material can withstand per cubic meter, or square meter if it's an impact test, or per linear meter. And so what we'd like to do is engineer materials that take up as much space on this graph is possible, that are a combination of being stiff and being strong, but also having a high strain capacity. Now the modulus-- oh, yup? AUDIENCE: Is that to rupture, all those curves? WALTER VOIT: These are to rupture. So these are the strain to failure points. And so what you see on this far end of the curve-- let me get a laser pointer out here so people online can see me. One moment. Yeah, perfect. So if you were to take the slope of this line in the very, very leftmost region of this graph, that's called the linear elastic regime. And that slope is the Young's modulus. And that sort of tells you-- that's effectively the stiffness of the material. So if we want a material that's soft and rubbery, we need something with a very soft or very low slope right here. But something that as you strain it, it sort of strain hardens and get stiffer and stiffer. And by doing that, we can get a very tough material that's very soft and behaves like a rubber. If we want an extremely tough material and we don't care what its feel is, we don't care that it's soft or stiff, but we just want it to absorb a lot of impact. You'd like a material that's fairly stiff but not brittle, and then as you get past this yield stress point, you have a huge strain capacity until failure. And I'll show you some of our curves in just a minute. But so what we have is a couple ways now to engineer the effective stiffness of a material. One way is by tailoring the stress strain curve, and another way is by tailoring this internal geometry. And this internal geometry is not something that you can do with conventional manufacturing. So for instance, let's say we wanted to build an insole for a running shoe. A lot of that insole is actually wasted material. There are certain points in that shoe where stresses are transferred from your foot down to the ground. If we could engineer material for those parts to effectively translate the stresses and have everything else essentially be a very low density foam, we could reduce the materials costs, we could reduce the weight without any sacrifice to the end strength of the material. There are no conventional ways to manufacture parts like that. That's why these market projections think that 3D printing has such a place in manufacturing markets, even though today it's more expensive than injection molding, than extrusion, there are just things that you simply can't do with conventional thermoplastic processing means. So let's look at some other parts today and how 3D printed parts stack up against them. So what you see in the top left here are some of the world's best materials. They're some of the world's best plastics. These are different combinations of polyestheramides that have sort of a stress of 10 to 18 MPa, but have a strain capacity all the way up to 1600 or 1800, so this is something you could stretch to 16 times its original size and then it's going to sort of snap back and not deform. So these are very, very tough materials. Here are some materials, some nylon based materials, that when you combine them with small amounts of carbon nanotubes, or single-walled nanotubes, or buckyballs, or carbon fibers, you see you get this big increase in their stress without a large sacrifice to their strain capacity. And again, these are non 3D printed parts, but these are some of the engineering methods that are used to increase the properties of parts. So now looking down here, what you can see the difference between injection molded parts and then a 3D printed part. So here's an injection molded part out of this material. And this is a PA-12, so a nylon based material. And you can see how little strain capacity you have once this is 3D printed. So when this is 3D printed, those layers simply don't stick together well, so the neat material has incredible strain capacity, the printed material is tiny. Same thing over here. You've got this 250% strain capacity for an injection molded material. You've got a 30% strain capacity for the 3D printed material. The story is the same. Wohlers released a market report in 2015 that looked at a lot of the commercial 3D printed parts, and most of the strain capacities of those parts were in the 10% to 30% range or lower. But it was difficult to 3D print parts that were a lot stronger. Google recently was part of a fund-raising round for carbon 3D, which apparently they haven't released too many stress strain results of their materials yet, but can print fairly high strain capacity materials. But perhaps at very limited toughnesses and very limited stresses. So what are some of the innovations that allow us to print these materials? Well the first one is sort of a new printer that we've developed that right now we're calling the Z cup model. But what we can do is we can package our resin inside of something-- you guys maybe have used Kurig K-cups. You can stick a little piece, a thing of coffee grounds into a machine, you can push a button, and it makes some coffee for you. One of the big problems with handling resins for consumers is that you have to handle those resins. Often they can be noxious, they can have odors. We can package our resins into these little sealed cups, these guys plug in to our printers. We can manipulate the height of something we've call a Z fluid, which is a material that's a little bit more dense than our monomer resin, and then we can very rapidly print things layer by layer within these Z cups. So what that printing system looks like, would be you can injection mold or mass manufacture a Z cup that looks like this, fill it with a little bit of resin, seal it. Depending on what kind of resin, you may have to remove all the oxygen from the Z cup. Some kinds of resins you don't have to do that. And then in the machine, we can inject the Z fluid and control how parts are being printed. So let's get here now to some of the good stuff. So here are some of the stress strain responses of competitor materials. And we've been able to get things that have a higher stress and have a much higher elongation. These are some of the parts that we're printing today, we're doing some work. I was at GE a couple months ago and gave a big talk on some of our 3D printing there. We've done some work now with the NNSA, the National Nuclear Security Administration on some 3D printing, and with Halliburton, and with a car parts company called [INAUDIBLE]. They build some interesting automotive components. But we've got these materials where we can tune this initial modulus, so we can say how we want these materials to behave at room temperature. But then we've got pretty nice strain capacity, so these stretch to 100% up here at 15 or 20 MPa. So this is a little Chinese fingertrap that we built out of one of those materials. As you can see, a lot of the parts that we're showing here, little toys and games, a lot of our clients don't like us to show exactly the parts that we're printing for them. But what's also really exciting is some of the experimental materials that we have in development. And so these are materials that unfortunately in a public forum like this, I can't talk at length about. But I can give you a glimpse at some their thermal mechanical properties. So this is a material with close to a 400% strain capacity, that has a stress up to about 50 MPa. So this has a toughness of about 100 megajoules per meter cubed. So these parts that we're printing right now daily for a lot of our customers. That's about a 10x improvement. If you look at the 30% percent strain capacity that a lot of current 3D printed parts have. This is between a 4 and a 10 x improvement over rubber-like and viscoelastic materials. This would be another 10 x improvement over that. And these are parts again that have very interesting properties, but by tuning the polymer chemistry, tuning how they behave as a function of temperature, as a function of frequency, we can do some neat things. And so if you want to follow up with us, we'd love to talk to you guys in more detail on the material side, on the business side. I'm sure she can handle a lot of that follow up. I've got a couple other little side things I wanted to show, some other fun projects we're working on back at the University with some polymer chemists there. But one of them is being able to 3D print self-healing materials. So we've come up with a really neat reaction. This is a furan-maleimide reaction. It's been known for a while, but we've found ways to take advantage of this reaction and functionalize even conventional materials like PLA and like ABS with some of these pendant side groups. And so what you can see here is a PLA blend that we functionalized with these furan and these maleimide reactions. And they undergo a high temperature reversible Diels-Alder reaction. And so what we got here is a material that we broke apart the first time. And so that was this point up here. We basically heated these up and shoved them back together. We did another stress strain curve, then it actually broke at a different point, which we're really excited about. So we were able to heal something basically stronger than this point where it was before. And so we think there's some really interesting opportunities for taking very low cost, conventional materials and finding ways to post-functionalize those materials with pendent side groups to give them some interesting properties in materials that can be 3D printed. But we think some of the real success lies in the ground up engineering of systems and of materials to solve these really interesting anisotropy issues that we see in the market that are limiting the broad adoption of 3D printed plastics. So with that, I didn't prepare a whole lot of slides, but wanted to leave plenty of time for discussion, and sort of speculation about maybe where this field is headed. And wanted to get some of you guys's take and interest on why you're here. So thanks for your time. AUDIENCE: [INAUDIBLE] WALTER VOIT: So the question was whether the shape memory polymers would fatigue as you're bending them over many cycles. And so it's a great question. There's a curve in material science called an S-N curve, which is a stress plotted versus the number of cycles. And so if you stretch materials to their yield strength, or the ultimate tensile strength, and you do that repeatedly, then they will fail after fewer numbers of cycles. So a lot of these curves that you see here, this is the failure at one cycle. So what most materials do is you build in something called an endurance limit, which is a safety factor that's some fraction of this, and we can guarantee that under this stress profile, a material will never fail. And so typically what you do is you take some fraction of your yield strength, you make it less than that, this is the linear elastic regime, and then you can cycle material hundreds of millions of times without any adverse effects to the network structure. AUDIENCE: So you're saying even you warm it up, it can become fatigued? WALTER VOIT: So when you warm it up, it won't fatigue unless you stretch it pass this endurance limit. And so we can define an endurance limit based on how stiff and how stretchy each material is. And you can heat it up and cool it down indefinitely. That will not have an effect on things. But when it's heated, as long as you don't stretch it beyond a certain distance, you can keep doing that cyclically. AUDIENCE: And about that self-healing material, is that a one shot healing procedure, or can it be repeated? WALTER VOIT: This is one that can be repeated. So at high temperature, this reversible Diels-Alder reaction is sort of favorable. So the monomers are just as favorable as a joint polymer as a function of temperature. So you get to the right temperature, these reactions are sort of an equilibrium. So you can basically make and break these bonds really nicely. So depending on how many of these we functionalize onto our materials, we can control how well they stick back together. Now, if you have just a few of them, then they're not going to be as strong. But the material is not going to be as brittle. And so there's a balance then between ultimate tensile strength, strain capacity, and a lot of these pending groups. And unfortunately in a big talk this, I haven't gotten into a lot of the very hairy details in polymer design. But there are a tremendous number of features of the monomers that we choose, and how they interact, how they polymerize, what they're starting viscosity is, what their side groups look like, what the kinetics of that reaction looks like, that go into the ultimate design of these materials. But today, I wanted to just show the properties. And say maybe some of the market skeptics out there, that we material scientists may in the near future have a great solution to help a lot of these businesses, who've really thought a lot about 3D printing, but so far haven't been able to print the kinds of parts that their customers need. AUDIENCE: You talked about the Z cup for printing some of these smaller parts. How do you handle printing some of the larger pieces for like, oil companies? WALTER VOIT: Well, the reality is that this Z cup model is highly scalable. So we've joked around a little bit, but we could have a helicopter lowering a giant Z cup into a swimming pool, and we could print a canoe if we wanted to. Now, I mean, that's a little bit unrealistic, but as a thought experiment, there's no technical limitation from keeping that from happening. It's just a balance of the intensity of, in this case, our light. And we've played around with both ultraviolet light projectors and visible light projectors. And so depending on the initiators we use, we've got a lot of control within our systems over how they're initiated. But we could do this on very large scales. We've built larger Z cups, that are printing the kinds of parts that our friends at Halliburton like, for instance. AUDIENCE: So one of the things I've noticed as a issue with 3D printing for production is just the speed of printing the materials, versus injection molding or forging or something like that. And are you able to address that? WALTER VOIT: Not as well as we would like, certainly. So the question was that in 3D printing, speed is often an issue, and that 3D printing can't compete with injection molding, with extrusion, with maybe blister packaging, and other things like that for making complex shapes. And that is a true limitation for a lot of 3D printing. Carbon 3D, a company that you guys have recently invested into, has come up with some really elegant ways to very quickly print parts. But a lot of the customers that we've talked to have lower volumes that don't necessarily need that kind of speed. For them, the driving issue really is the underlying materials properties, and not the print speed. So, I mean, these aren't taking weeks and months to print, we can print these in sort of 20 minutes to 4 or 5 hours. So it's not that they take forever, but it's also not that we're right now able to pull parts out of a liquid resin. But I think as we continue working on making these faster, I think that the driving issue, for what we've seen from a lot of the market reports though, is not that the volumes of 3D printed parts are too low, but it's that the materials properties aren't good enough. And so I think we're coming at this problem maybe from a different angle that Carbon 3D is, is that we're really trying to focus on printing tough rubber materials, printing tough viscoelastic materials. And I think the speed is something that can be engineered into the system, whereas the underlying materials properties maybe can't be. SRISHTI GOEL: Walter, can I add something to this point really quick? WALTER VOIT: Maybe come to the microphone. SRISHTI GOEL: So, the other point that in general, the benefit of 3D printing that a lot of people, I think, miss when you first start thinking about the subject, is yes, 3D printing takes a lot of time. But if you consider the amount of time it takes away from things like having to redo your tooling costs, to actually having all of the other changes you have to make. If you have one 3D printer, it can print anything from A to Z, right? You don't have to change your tools. You don't have to change the assembly line, you don't have to do-- if you have to change every single part for some small specification, you don't have to rechange your entire assembly line to fix this one small error. You can just change your SDL file, and suddenly you're there, right? So when it comes to time, that time efficiency is spent more on actually making the part than on making all of the infrastructure for making the part. And that's where we see that even though 3D printing might be smaller and materials might be more expensive, at the end of day, you're actually getting a more cost-effective solution. AUDIENCE: So a quick question about, I guess that you guys are making the material as well as the 3D printer. How about like the slicing in the software that comes behind it? Is that something you guys created? Are you using off the shelf product? Or, how do you do that? WALTER VOIT: So we've done a little bit of dabbling. I'm on a computer scientist by training. I did my undergrad in CS and a master's in Artificial Intelligence. That's how I knew Chris back in the day. He stayed on the dark side, I went over to the light side of materials. No, so we've built a few of our own systems to print these materials. So we've written some of our own scripts and software to run the printer to do the slicing. But to be honest, we would love an infrastructure like you guys's behind that, instead of relying on what we've sort of done with chicken wire and chewing gum. I think there's a lot of need for-- especially as we get to some of these complex internal geometries that we've passed out, there are a lot of very sophisticated algorithms that can generate fractal-like patterns, that can generate complex internal geometries, that can map, let's say, a finite element model that you've generated in Abacus, into a structure that once you've 3D printed it, you can localize the stresses and strains appropriately. I think that's a huge area where software companies have room to play. I know that HP has recently made some acquisitions in that area. AUDIENCE: What's the cost of the resin itself? What's the difference between just traditional nylon, between [INAUDIBLE] similar properties as injected? WALTER VOIT: These are resins that are not quite as commodity as something like polyethylene or polypropylene. But they are not far if you look at petrochemical distillation, they're not far from crude oil down the distillation pathway. So if there were a need to mass-produce these kinds of materials, it would be very inexpensive to do so. Because the volumes aren't as high now as they could be, they are a little bit more specialty resins. They're a little bit more expensive than traditional injection molded parts. But we look at what other 3D printing companies are charging, following the razor blade model of essentially giving away printers and then charging a lot for resins, and at the lab prices that we're making resins now, we are more than competitive at those price points. AUDIENCE: Just a couple quick things. First you mentioned being able to vary the Z height. How far can you vary that? WALTER VOIT: What's really neat is we can do that during a print. So if we had some components that structurally we wanted to print some layers very quickly and we want a lot more resolution in another layers, we could do that. It's a balance of what kind of initiator we have in the material, what kind of inhibitor we have in the material, what the height is, what the intensity of the light is, and how these little micromeres are turning on and off. So a lot of projection technology has advanced algorithms that make the edges, for instance, look sharper and pixels. So the mirrors are turning on and off much faster than the human eye can see to give you some interesting edge effects. So there's some interesting ways we can play with that combination of inhibitor, of initiator, of layer thickness, and of software to control that. So one thing that limits how thin we can do that, is the viscosity of our underlying resin. And so different resins that have different properties have different viscosities. In the lab, though, we've been able to spin individual layers that are less than a micron thick. In fact, we've been able to spin down some of these kinds of materials-- now this is a solvent-based approach where we have to let some solvent then evaporate. But we've been able to build 20 nanometer thick, very uniform films, and do some neat things with those. Now, that's not really realistic to print large area 3D printed parts, but for some of the photolithographic processing we do, for instance, for building microelectronics, often we need a 20 nanometer thick dielectric to do something. And so we've got some abilities to spin these materials down to those thicknesses. In terms of the thickest, it depends again on the inhibitor. If you start to vary the thickness within a print a whole lot, it becomes difficult to balance the inhibitor. Because as light is going through this material, as a reaction is propagating, you don't want that reaction to propagate and turn your whole resin into a big ball of goo. So we need ways to start that reaction and stop that reaction. And Carbon 3D has their own way to do that. We have a very different way to do that, which gives us a lot more control over how to start and stop these reaction. AUDIENCE: So what you do with the leftover resin in the K-cup model? Because it seems that you have a fixed amount of resin for any K-cup and so is it just because every single one is going to be custom designed for the part that's being made? WALTER VOIT: Yes. So for high-volume manufacturing, companies would be able to specify exactly how much resin they would need. And we would have very little waste at the end of the day. In these cases, we pushed the Z fluid up higher, and then we polymerize a little A3DT disk at the top that's a little knickknack that we can play around with and hand out as swag. In the future for highly customized parts, that would be nearly eliminated for more of the maker community. There would be different SKUs you could buy for different size resins, and then it would be up to individuals to determine what to do with the extra. But in most cases, you would push it to the top and then just finish polymerizing it. SRISHTI GOEL: So the other thing is we're actually, because of this problem of having waste resin, we're doing a lot of studies now that are internally focused on what kind of-- what quality of print do we get if we reuse our old resin. And so we're seeing that actually if you use-- if you need something that's low quality, if you're not super concerned about what kind of properties you're going to get on the end user, then you can actually reuse the resin and it works pretty well. So we're actually working on making that less of a waste situation, more of a recyclable, more sustainable solution for having to deal with that kind of thing. WALTER VOIT: So the question was whether we were focused in medical markets, because it seems like this control of stiffness and internal geometry and materials properties would lend themselves well to that. That's something that, with my other hat on for a moment, back at the University that we're spending a good deal of time on. We have a DARPA grant that is focused on 3D printing some artificial tracheas with colleagues at UT Southwestern. My wife is actually here sitting in the back. She's an ear, nose, and throat, head and neck surgeon at UT Southwestern. And so we're working with her and with some of her bosses to do that. But in terms of market adoption for a small company, you can live off of grant funding and things for a long time. But in terms of readiness to market, there are quite a few barriers to entry, and we've focused a lot of our immediate concentration on these near-term, high-value industrial markets. And I think there's a huge segment for medical research. But that will come. As a company is adaptive, we've focused squarely on the non-medical space so far. But I think we'll continue to build an IP portfolio that may lend itself to that in the near future. Thanks a lot for your time.
B1 中級 Walter Voit:"極速3D打印:以材料為中心的方法在谷歌的演講:"注重材料的方法 (Walter Voit: "Extreme-3D Printing: A materials focused approach" | Talks at Google) 205 9 richardwang 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字