Today we have the session on functional composites led by Professor Ed toss, since it was faculty and mechanical engineering and data science and engineering, CCNE. And I was a PhD student. So they kind of know a little bit about the wagons. Very exciting. He's going to talk about carbon nanotubes, it's processing, characterization, and a lot of different applications. So I'll hand it over to Dr. Tall sensing for the overview and then will be followed by a majority and a hands-on were PhD students in Mechanical Engineering. Okay. Thank you staggered for introducing us. As I mentioned on Eric oxygen side on faculty in mechanical engineering with a joint appointment in Material Science and Engineering. I'd been studying composites for a long time. So in fact, many I know that there are many students on the call right now and I was a number of years ago in your place. So I thought I'd actually retired from giving GTM research reviews when I became faculty, but it's actually a terrific experience as a student. And I'm happy that a continuing it's actually encoded. So OK, for many years now, I've been involved with ongoing integrated research and processing characterization modelling of nano carbon-based composite, specifically carbon nanotubes. And what I'd like to talk about today is our work over the past several years at utilizing these nano materials as sensors. And the title is multi-functional fibers and composites from almost nothing because we use a very small quantity of carbon nanotubes and they're so small that you can't see them. So okay. So I always like to start with the side and I, especially for an audience that is deal frequently with traditional composites. Because I really think this highlights the vast difference in scale when we talk about nanocomposites as Turkey to traditional fiber composites and that to some of my work as a PhD student many years ago now, where I grew carbon nanotube directly onto the surface of carbon fibers. So you see here is a woven fabric and individual fiber with carbon nanotubes. And that individual carbon fiber is about seven micron in diameter, about a tenth of the diameter of a human hair. But all the little look hairy things, what we would often called a fuzzy fiber. Those are carbon nanotubes and those are on the order. Seven to 15 nanometers. So again, three orders of magnitude smaller. And this was particularly the challenge is now we're dealing with district reinforcement scale. But it's also the opportunity, particularly this ability to combine reinforcement scales. And over the years, we've developed a lot of processing techniques and they handle, I'll talk about that a little bit today on how to combine fibers and traditional fibers, nanoscale reinforcement together. And this is really the enabling technology that allows us to look at some pretty cool applications and emit, we'll talk more about some of the applications and smart textile that went out to the student, it out and natural now Technology Initiative that just come out. And I think that there were a lot of discussion about how the nano would revolutionize manufacturing is that we're going to build materials from the small-scale particles and powders from the bottom up. But as a student and composite, this was something that was already very familiar to me. As I think. It's something that for decades, engineers and scientists working in composites. This is the approach that they, biologists really bottom-up. And even when you think about traditional fiber composites, you're selecting a constituent, you're tailoring their interaction at the interface or interphase, which is certainly at the nanoscale. You're orienting the fibers in a certain direction, bending and twisting them using textile techniques. You're laying them out, you know, a unidirectional sheets all the way up to the Net Trade composite. And I think as an engineer, really what intrigued me was just capability to design the material at varying like to scale. We're not just, we don't only just design the final part geometry, but we tailor the microstructure and now the nano structure. So when we started getting into this, and this was actually when I was a postdoc and I was doing a lot of work looking at how processing affected the electrical properties and material maxima that the graph that you see on the left. And I think one of the unique things is because carbon nanotubes have what we call very high aspect ratio, length over diameter. They palm conducting networks quite readily at very, very low concentrations. So here what we see is electrical percolation, which where the material goes from insulating to conducting a, changes several orders of magnitude and the volume resistivity at Jeff adding 0.1 weight percent carbon nanotubes, almost nothing. And then really what happens is that the conductivity is dominated by the individual tubes that touch each other or are really close. And are there such that electron topple over so that Matt is what we call this electron tunneling between the tubes. Or you can think of it on another level is really kinda this nanoscale contact resistance. And one of the unique thing that says that one I like doing this work. I started bending and twisting the specimens when I was doing the electrical measurements. And I could see the electrical properties change as I defined that. You can think of these nanotubes or whatever the reinforcement is, that conductive is really like these discontinuous wires. So you have all these little contact resistances. And if you stretch the material, the distance between those wires change. And as a result. Contact resistance changes. And I think what really kind of kick this off the bat. I thought that that was neat. I sensitive compared to a traditional role strain gauge, but I thought was unique as well. What can we use the suspense damage. And so what we get cracks in the material, we start permanently severing some of those wires are the conducting pathways. And so this is a micrograph but you see a crack, I really small crack, a microscale crack, and you see all the little tiny carbon nanotubes that are protruding into that crack. And I think this was when we first started doing this work that was really unique application of nanotechnology and very practical application of nanotechnology. Because in order to sense a micro-scale crack, you need and nanoscale layer. So today, as I mentioned at the beginning, so emit, we'll talk about some of his work and how we use applied the sensing technique to smart garments using a nanocomposite and applying that to the surface of the fiber De Han. We'll talk more about one of the techniques that we've developed and patented in my laboratory for manufacturing nice composites and doing it in a very scalable way. Ultimately, as engineers, we might do fundamental research, the engineers are always interested ultimately in an application. So today I'm just going to highlight very quickly before I turn it over to omit and day and some of the work over the past few years where we've taken from the fundamental work. And our manufacturing techniques are really the enabling technology that allows us to look at much larger applications. The first one I'll talk about is utilizing this material for structural health monitoring. Specifically in the rehabilitation of infrastructure. That research was funded by the Federal Highway Administration and also NSF. And then I'll speak briefly, the fry, we introduce a bit about some of the work we've been doing over the past few years. And developing novel, novel economic based sensors, particularly for tracking human motion. Now it's funded by NIH and also in initiated on campus, funded by unit al known as hen's where. So again, when we think about nano materials, we often think about very small. But this is just an example. Hongo Dai, who has a PhD student and also a postdoc here at the center, did his work in this area. And what you see here are those black ramps. Those are what we call your apps or shear wraps. On the left-hand side, this is a sectioning put beam that has deficient shear reinforcement. So on the left-hand side, a composite with a integrated carbon nanotube centered as quite a large sensor. It's probably about six feet long, a couple a foot and a half wide. And on the right-hand side you see the centuries without reinforcement. So what you see on the left hand, on the right hand side is without a composite reinforcement on the left hand, our glass fibers to impart re strengthening them to the beam. And again on the left-hand side, this is, you'll notice some familiar faces than those that you're in that picture. But this is also where we're manufacturing a on a, on a very similar being that you just saw. A tension reinforcement and we're doing a vacuum and fusion. And between that reinforcement and the beam itself is our carbon nanotube sensors. So we've been able to scale this up fairly large. And next couple of slides, I'll highlight some of the work that specifically funded by the Federal Highway Administration and how we can utilize these centers to detect fatigue cracking. So not only to rehabilitate or structure, but detect the growth of cracks in Madame structures silence specifically steel bridges. I think. Of course, if anything from the news recently and there's not a lot of talk about infrastructure and they actually happened this time. But a court that the challenges that we have, a lot of bridges that are either functionally obsolete or structurally deficient over time. And that's due to a lot of things corrosion, but also the initiation of fatigue cracks. And on the right hand side, this is actually a girder and embrace that's in Delaware. And one of the traditional ways YOU CA that they're the fatigue crack, there's also corrosion and that crack and you see that they've drilled holes to stop or try to blunt that crack tip. And one of the things we're interested in doing is it's rehabilitating these cracks use and composites are the problem is is that when you bond composites over the surface, it covers up the damaged so you can't go out and inspect it anymore. So we had this was initiated with bow that where we did some monitoring and developed this approach. Well, we could rehabilitate. So we've taken that's from tiny tubes actually to implementing this in the field with. So in addition to our fundamental work in the lab and centers, we have two of these centers on a bridge. This is the South Walnut Street Bridge that you see that actually one we're going in inspecting and looking for the cracks that we found or that we're on the inspection report so that we could design a solution for it. So I am faithfully dry land taking the picture. So this concept with you utilize a structural reinforcement and at the inner base is to embed our carbon nanotube center. And on the left-hand side what you see is a crack. And add the crack grows that sensory fragments. So we're able to detect the position of that crack. Then we can also add a structural layer in order to rehabilitate that. And we've done this out. So this is, I think it's a unique aspect because we can apply both re-uptake, repair and rehabilitation as well as moderator at operators area, something that's very sensitive. As a result, they have low power requirements. We power this with just a solar panel on the field. And it provides real-time feedback. We send this data over the network and what you see on the video. Hopefully, if that's coming through. I don't hear that it's not. So what you see in the video, is that in the video the oh, sorry. I think that I clicked the wrong button there, so my apologies. Okay, but nonetheless, on the right hand side, what you see is a centre response. So this is, we've done this in the laboratory, but we've also done a lot of simulations. What you see here, Israel, he gets to crack growing these kind of classic type thing that you see the crack growing and you see that perhaps intensity at the crack tip and that gets larger, that region of the stress intensity gets larger as the crack grows. But the concept of adding a fiber composite on the left is that what happens is when you bind a fiber composite and onto it, that composite starch to carry the load is to crack grows. And what you see actually on the right hand side, the principle stresses in the steel and centration decreases actually edge crack garage. So in the laboratory, we've been able to validate this looking at both traditional repair, you drilling a crash-stop whole, but also composite type repairs. Or these are just some pictures of this specimen. They're fairly large about footwear within went out our structural repair. And I think one of the things that I found intriguing that grueling, that drilling, the crash-stop whole, I really didn't do anything. I had increased, on average about seven to 10 percent. But it was certainly within experimental scatter. Whereas the composite repair approach increased at a close-up on a 100 percent over 100 percent When we also did a traditional repair of drilling, a crash-stop Hall. In addition, our sensor with able to quite effectively monitor the growth of that crack it, whether this venture with under load or not. As I mentioned, this has been implemented in Wilmington. First time we are adult, we actually as a drawbridge, we got trace chain stop the bridge by the calmer nickel. So they waved and smiled at one time. We weren't too happy. But this is the fatigue crack that we repaired. It has both a structural reinforcement as well as a center in the lower right hand corner that is a bridge and Portland, Oregon, which is multimodal bridge on the bottom there, Israel, you can see an Amtrak train band on the top is moles, pedestrian as well as vehicle traffic. And then here, again, what we have, if you go down and you look at it, you'll see a solar panel on our data acquisition of hanging off the bridge. And we are transmitting that over the network so that we can look at it in real time. And certainly the Dao that engineers can monitor and it's very difficult to inspect these cracks, but you can keep an eye on them virtually. So the last part I just want to mention is as an initiative here on campus called hemorrhage where and then also where we looked into a kind of an exciting new area and taking what we've been doing and applying it to everyday fabrics so that we can create garment based sensors instead of, instead of monitoring structural help. We can monitor human health. So for those who might not be aware, there's an initiative on campus. I was funded by unit Dallas led by Professor jail Higginson and mechanical engineering and also Delaware rehabilitation center. She is leading this initiative to create the fabric of functional garment Research and Leaves. So it involves things such as textiles and fashion and on parallel studies, centuries support, which is actuation as well as active as well as pass or Greek art, feedback and control. And then ultimately, the goal is, is that there would be some healing and perhaps learning by patients. So this is just one example. There's been a number of pilot projects out focusing on different areas such as Hampshire and recovery devices or different types of gloves are different types in the system. Garments and bass, bass. And one I'll mention is what we can do and integrating these into sort of an NDA in the clothing so that we can monitor people not only in the laboratory setting or if you go into a physical therapy clinic, but as if you walk around campus, we can acquire that data. On the left-hand side. This is Alex down in the lab. If you go down to the Shire campus. Beautiful abs down there. But you'll see they have these very complicated assemblies that are bulky. And it's really limited to looking at in the laboratory and they react very complex and expensive motion capture systems. On the right hand side is just some work of cyber dosing our host for today. And where we see is that black area is a textile center that Wheatstone onto a compassionately. This is a traditional nylon spandex material. It's soft, it's breathable, a soft to the touch. It's readable. You can add in any color you want just so long as this black. But on the bottom side, what you see also is our data acquisition. We've been able to miniaturize it. You can see relative to the smaller than a credit card. We'd rather than a number of different sensors. One, it is two very thin and flexible sensors that you can put in your shoe. And what you see on the right hand side is there's some video undergraduate intern walking and we can measure those reaction forces. So instead of walking on an instrumented treadmill, like what you would do, you can lock on instrumented shrews. And you can see actually those are the shoes I'm wearing today. And very thin sanctuary that can just be something between the install. On the right hand side is what you see is our sensor response. Black line on the far right. That's what we would get from a treadmill. So what we see are these. What we see is actually we are able to separate both the ball and heel of the foot response. Be censored have remarkable dynamic range there for their tactile sensors, you can touch them and there's a response. But on the far right hand side, you can see we drove over it with a forklift and the manufacturing lab. So really from touch to tons. And now that we're not limited to walk on a treadmill, we can monitor as you walk around on different terrain up and downstairs. And that's what you see on the left-hand side. You can see obviously you shift your weight. So this is can provide feedback, particularly if you have an injury and you stand out too much. So I won't go into that much detail. But I do have a couple of videos here. Hopefully they're coming through, but you can see as a subject moves their arm, you can see that response in the background in real time. And what's remarkable is that at mid fraction, which is about 90 degrees, what you see is a 3000 percent change in electrical resistance. So there are narrowly sensitive. And again, that sensitivity here you can see the subject clenching of S. And you can also see just that very slight motion we're able to pick out. And again, because of that high sensitivity, that's what that normally we end with a conclusion slide, but I think they were still developing their conclusions et al, ongoing research and moving into exciting new directions. And I just want to finish on acknowledgments. And of course, all the students who do actually do the real work, of course submit and May Han are speaking today. Theta is another student who's silent and working on with myself and Professor mirage snake. Some different aspects of this and a number of students solder, Colleen Hong low shall peak and others over the years and collaborators in civil engineering as well as in mechanical engineering and biomedical engineering. And our colleague Andrew writer and Australia and a number of research funding. So with that, I, I'd be happy to take questions either. I think a time to move on, right? Soccer. So perhaps I'd be happy to take questions at the end and chat, but I, I want to turn the floor over to the students who can talk about the research they've done over the past year. I already do. Next. You're gonna start shedding Husky. I don't see, um, uh, done the day on. Do you want to go next and the meantime? Join in again? Yeah. That'll work. I oh, yeah. Yeah. Yeah. Ahmed, you might have to do the spleen is not the full screen mode. Yeah. Yep. Good weekend. Right now. Still can't hear you. You're muted. They want to dial in via phone. I met. I'm OK. Now I can hear you. Yeah. Thank you. So hello, everyone. I'm Dr. Jensen. I'm getting towards the API, get Ananda research and understand tranches. So I think it is a forced to sort of your ischium items, panicle nasty about that, a candidate to COVID. And maybe I'm going to be presenting some part of such an mechanics of the church and how beautiful graphs and chain nitrogen be putting on the rabbit. Just started like I'll just go through some of the work we're doing and then I'll just move on, potential victim and understand their concerns. Anxious, which like holiday late there, The Best Buy Target and other potential. The alcohol or the main part of the extension mechanics and some part of the editor, the fovea, depending on the fabric. Industry, target multiple components. You have the reports from WH a lot of people are aging now. And by tonight, there'll be like you don't want to double-check the ages and so backward like there anymore, we're getting more and more assistive devices. And that if you see them algebra, It's going pretty well. So if you look at the light, astrobiology, look the part that related to that directory mechanical adding that. There'll be very little support and some small molecules go grab IntelliJ. But in the real time you can see a lot more, a bigger chunks which are like lot of mechanical and electrical, a lot of integrals are there. Enter we can control the device remotely as well. So if you look at the devices and the biggest part, like four days antibiotic, we're going to human-machine interface and what behave in anatomy, the partner relationship, you have a complete and accurate us. And I really like get handouts for the budget planning data lake, being able to and still get the fabric. It can work at Yale Center on a dissenter equitable. And if you see like there's a lot of examples in your market, your shank as a living for your bank or cash outflow temperature, but they have got intestines. So what we are doing, we are done are some petals. I'm just timestamps and this can be easily integrated with the guard match and you can use to capture that movement of the body. It can be like a substantial and legally extension tours. So I will give you briefly how the nitrogen. So one of the metrics, each polynomial at that It's called decoding. Decoding we mostly, we just use the commercially available dispersion between, I guess they don't want that and you just add lumbar Italy's and God that we did the fabric, keep it in order portraying and then fabric. I like the layout of God, carbon nanotubes and a under two. Now. Now the other method which unlike the developed by Obama, got in the middle and that is called electropositive, the Bayesian. So in that matter, we are making, I can't easily search and we are the he comes night that carbonyl due to the high both Nigeria polyacrylamide, which make them TMDs quartile. The same negotiated a positive charge. Oh, it looks like a uniform and a report that fabric on a toad. I need to pay the original data and the Dutch empty because you look from that opened up public money and start forming on the cathode, goes onto the subject, I will, I think the model of the work. So so how did allow iodine atom that we are gonna be no central bonding atom and the nitrogen. So if you look at the passage, I'll just give you a little bit of an IQ of a base. So we'd better tell, I've made up non-unique elements. So they are not straight UP, but it can reconverge. And the equity chance to like eat they can recognize does go like heavy load. And if you look at Changi part, we apply very heavy load for the megapascal. We calculate tension, go to 35 percent. Now, how they work. So when we, when we started, when you decoded the carbon nanotubes, then you calculate your People are still on a completed form on the pilots are kids under which again, can be electrically establish an adequate devoted to regenerate. It was like there when you comfort or fabric that the climate changes. So you can have more of work on muscular fiber. So they do more and more contexts. And also getting local people still want to do. And a compositely at night they're merging together. Can we grow older? They had the latch can go down to the more contact area. But when you look at the strange answers. So how are we met the extension of mostly in our DIBL? Because carbon has builds on next fabric now. And if I produce a table, so it is to add them and we can maneuvers can change the density. So in the lecture, I want to share it. It has teams and our SHA, everything. Now if you see this, the only cells in this video. So here is tangential and competently. Can calculus just go to 100 percent? Now, if you look at the plants and the cutoffs, are the tension while on the clerk go 35 percent or 40 percent more than the stereocenter at its Pluto TV. Pretty high. So definitely like the mechanics behind your head knowledge forward. So bandwidth that you can culture them for the patch and update only. We actually tangent direction. I can actually put in that data can only go to what to give us the keyboards and which is not much. But when you go Hold on, elbow is called the highs. So that cautionary like yb, so Castlight I just showed on your tablet in a letter between looping of the young yeah, interlock. And it actually left just again. So that actually preferred perform multiplication like it will direction, like how vanished huddled actual body to the public to investigate. And I for this, possibly did you check them? Forget how DNA listed. So the hospital is not a stretch at all. The second protection that upper is taking the length of this EDA. So if you go back now, I'm just naming the lag. You say that you and the head. If the lag between when the comical into fabrics. But we did another experiment get the magnitude here of around 1.5 H in February or 10 milliliter. And you can see that unilaterally committing to understand the mechanics. Because I'm young testing, we want some yarn from the fabric. I did get them done with burgundy and we just technical language and getting them. The first picture like the shelf when he is charged on elongation, linear scan, beginning and the end. But if we go to appreciate young gender studies, people eating only, it's not bitterly. So that positive cognate forget like when we are taking a anestrus yarn is then on the fibers are coming closer, contact, multi-product of closure. So likely potential there is advocating. We can see that big Linda instance. Now, if you see closely the idea when he got to get to the picture of this. Now this is an important one. So in the hospital you can see like yeah, although I would start with the labia separated, tonic altogether, appeared to plug into the formula and I can chelate is coming closer and further the commoner late gets folded and you get it pretty close. So buggy. Mumbai. Yeah. When you tell the answer only then I can see like all the fibers are coming good at and what we're not going to start stretching. Now the second part, the second one we see like the Yandi or conduct. Now when D2 antagonist include contact, then the pressure will build up and that person will double beta ETFs together and relay their fiber to be close in contact. So on aging skin, the add-on content, fortunately it is, and that will be diva stands. So we do some coding and testing. So when people Diane and manipulate it, you can see there's money between your stance first and they'll start engaging. And they feel like they're going down to the long yam, technical to 10 percent. So a monastery and he can see and touch and let us do but built on stamps. Now, we tried to build a model built on yes. How are they behaving? So if you look at the left-hand direction like that, stretching direction, I guess, or blogging and blogging separate tense. So they're good for the leg. To call the head. I took all the lights. Now, if you compare the pearlite and stretch, you guys see that he can export your data like part. And you don't export an image and hide under giant in advance. And then illegally has tended to not significant, but in head and neck part in getting you to the Lambda well nitrogen. So there, I would say only one that you just bought two and how that will be not an electron it. So, but if he, if you look at the elbow applications than the relatively steady share, that elbow can stretch a discharge and the land actually got a lot closer to 90 percent and it also is stretched or compressed liquid around consent. So been published at a company like it would have to manipulate. And well, there are other network. So English is really changing the land, had oxygen. So we get negative two heads and two legs, but it's too late. And advantage on me. While you can just indicate. So this actually is still under the epithermal 30 units in coming days. So he tried to summarize like something about the net fabric. So did he not only one feature, they are multiple factors that are changing of the numerator is of course the king of the fiber and he had to get the fibers. Young lady day. Now. Secondly, I will have a contact. So when contact me directly, you can have a thought AND I contacted them. Now the fun part of telling that the cardinality of so many fibers and C and D has a tiny gap between didn't really lock that acute generalist and so intently. So I will cover partly how deal with the cognitive. To understand binary. Again, quoting, we do what they will do my best, decoding and encoding a lot about the position. So we did some test it again and go to the late teams. Got it. So when you pull up a bit geeky like a lot of merchandise coming opposite that if they put the samples, but if we did like with the swat man, a very deliberate, it's not coming up from the alphabet. We didn't. Second task, like when you take some model and we put the public Anthony, get it. I'm going to get an electron integrate that leg to 11 kilo pascal and GitHub, big coded and ADD but 12 percent. Now, we also noted that when you finally get the water, not only cognitive give, but there's some cabinets are coming off and then on to adding the loss of that. Now, we are also pop on what he does not get antibiotic, does your leg because that fabric they are making that will be mostly integrated with a small government and government have the leg, the fact that we do that with gammas like washing, so with some multitasking that too, like ADCC standards. So we're just taking that wasn't good. I will answer them load. And we got one more cycle, corporate units each and we're just making them do it. So when we compare the leg, wasn't that result contributed to him that notch and our dip coated tablet and non-human secondly, that the lake red color. So I'm only going to touch AGI and it's almost everything is gone. But if you see the decoder then be decoded, that's pretty stable. It's not getting adults with on the other side. And he also check the terms of the subject. So EPD called the can identity in the first second, it has some standards because I'm not quoting. And after that the mate guarding and if he she they are decoded. I delegate. So the numbers here because Coded fabric. We're not going to do a lot of hospice again. And here the picture of the cortex are great. So if you see that, it will be probably like after Noah's decode it, I think it adds to that guy and put a fabric. Now, here's I'm going on my work so we can relate. Yeah, it's a bit the illustrates changing actually technically because of the Beida case treads on the elbow and that it is also because of tubes. Now, we also noted that the ligand or the fiber contracts you do not in particular setting. So the whole egg on elbow achieved by the cash did not change and the case came to be able to notice or don't need them. Now we also need further testing to do input loop test. Here we can add them booked separately and we can have only live content to metadata instance. On the annihilate, the derivative denoted that decoders and the dawson certainly thinking or cycle, how did you do today? And I'm pretty sure that if I'm watching only and not the leg here, extra load on that particular thing then I think it can sustain better. Now I'm like do some TDL and he just so we can actually measure the narrative not in the fabric, very egocentric and it really, and also you want to test some other factors like how the tendrils are good for if you're sweating or until the late. So I'm not going to get on their land for these girls. Yeah. Thank you. Hello. Yeah. I guess we can move through that makes stuck and then take all of the questions together that if data okay. Yeah. Okay. Sorry. Sorry. Can I just drew? Yeah. Yeah, Good. Okay. Can you see my screen? Yep. Alright. Right. Thank you for that. I turn on my camera here. Oh, yeah. So my name is day hands-on. And thank you for coming to today's R groups research review. And the title of my talk is Tories roll to roll manufacturing of nanocomposites using electrophoretic deposition is a laser pointer. So as this is the first slide of Dr. fastness in his talk. So I'm going to I'm not going to mention very much. So as Dr. Dawson mentioned in his first line, a carbon nanotube hierarchical composites we are working on in our group as different reinforcing, scaled as well as distinct materials. The key challenge in hybridization is how do we bridge the difference thank skills from macro to micro or nano. So that the properties of these nanocomposites are very structure and size sensitive, size dependent. And like and like. Hi, Any, any hybrid systems, we know that we need to understand and be careful about the properties of the constituent materials before we combine them together. So taking advantage of the unique properties of constituent carbon nanotubes, we have been developing a variety of multifunctional textile composites, especially in Piazza resistive sensing applications. So we have demonstrated with real life applications as shown in these slides. But all these are called in Washington and emits talk. So I'm not going to talk about that much. But what I want to point out here is that an ultra high sensitivity of pressures than sort of a stretchable sensors manufactured in our group was enabled by a technique called electoral Friday deposition due to its special financing mechanisms. And this and its scalability is especially covered on my end today. So I'm, I'll start with a brief introduction of electrophoretic that position that we have developed and used for several years recently. And I'll show you a good example of hybrid composites are processed by electrophoretic deposition with tailored morphology and physical property. And there are some design considerations for scaling up this process for continuous manufacturing. Such as flipping between electoral electrode and self treat like glass fiber, carbon fiber, and the effect of gravity and perforations on the cathode working electrodes or the mesh side of that perforations. And if I have enough time to cover, I'm going to go with a deposition kinetics, but I don't think I'll finish it with future working somewhat. So electrophoretic that position basically uses the principle of electoral forces. This is a process like where positive or negative charged particles in a dispersions are driven by electric field, and those charged particles will migrate towards the counter charged electrode. So example, for example, the positive charged particles will go to negative. So that system is called k-fold week. So catenin is positive and the cathode is negative electrodes. So we prepare to aqueous dispersion with the positive charged particles by oxidizing and function analyzing the carbon nanotubes that ozonolysis and there'll be Pauling was called polyethylene wife. It has a mine groups or functional groups on each end of the branches that are readily protonated under mild acidic conditions. So I adjusted the pH to a five-point eight or six by adding gouache or at the SDG acid, then these are my ingroups, an H to become the next great plus. So the whole particles are functionalized. Carbon nanotube particles become positively charged. It's readily working in the dispersion by applying an electric field shelves as the processing method to directly hybridized nano materials on the reinforcing fiber surface, the EPD with a good alternative to chemical vapor deposition. There are a lot of advantages of EPD over CV that's more amenable to scaling of continuous manufacturing process. So it actually doesn't need to move existing fiber sizing and its process under room temperature and atmospheric pressures without any hazardous chemicals unlike CVD. So it's more amenable for like scalable scalability of the process. And here is a carbon nanotube hierarchical composites with last February called Astra parts. That's purely a quartz glass fiber. And we have modify the type of electric field applied on these dispersion systems. Direct current electric field, an alternating current electric field, which is one of the processing parameters, control the narrative morphology. So both processes can coach in a uniform conductor films on each single filaments. These circles are single filaments of ask recruits. And you can see the bright rings around it. So there are uniformly coated around it was like 100 or 200 nanometers thick. But DC PDE can build several micron on he coatings on the outermost surface only. But AC was able to drive more C and teeth into the inner toe regions. By suppressing the effect of dielectric water electrolysis to form a thicker coatings nibbana, the fiber bundles. So we measure the electrical resistivity, conductivity and in-plane and through thickness directions for each composites that have similar amount of narrative films by controlling the amount of relativity. And we visualize the conductivity difference by measuring the joule heating temperature change by applying constant voltages for a certain, a certain amount of time. Due to the different microstructure of functionalized carbon nanotubes with the fabric. Dc specimens in an in-plane direction, an AAC, It's bathroom, and a third thickness directions exhibited higher conductivity and temperature change. Comparative counter specimens. From both processing and performance point of view of the application point of view, we have motivated to scale up this EPD process that was usually conducted in batch scale and build a pilot line for a large-scale applications in order to actually. Perfect. Before purchasing the construction parts or components, designed a line initially focused on the deposition bath because it's barely CNT film morphologies and interfacial properties of composites are primarily determined. Though as beverage pass through the deposition bath, the type or arrangement of working electrodes need to be designed properly to get intimate contact between the fabric and the working electrode. In case, in this case a cathode. And since high strength of voltage is sometimes used, we also have to think of electrical insulation for our safety. This slide shows a design like different multiple design considerations before actually construct a line from our previous studies about nanotube deposition you and that microstructure formation mechanism in the batch process dissonance, qualitative and quantitative. That position behavior of functionalized carbon nanotubes. And we have down that intimate contact between non conductive fabric and the working electrode was very, very important to. Several experiments were conducted in order to determine final design of definition stage. We compare to its posit a mound or yield that significantly amount of the significant effect, the throughput speed or the production much. That's a fabric, moves continuously along the fabric. Between the two electrodes. A direct current needs to be maintained. And there are two possible configurations of the cathode. So this stationary and welding electrodes that makes slipping and non slipping between these fabric and the electrodes. And another experiment says about G arrangement cache, that the influence of gravity and the perforations, the holes of the electrodes on the deposition was investigated when the two electrodes are arrange it horizontally. So this red colored cathode and gray colored anode. So these two configurations of these electrodes birth considered and a stainless steel cathode with and without hole perforation were placed on the top and the bottom against an anode. And they found the perforations does not have negative effect on the deposition rate. The stainless steel mash was we thought that was a proper candidate materials considering a uniform opening size and that flexibility because in the shamed into a conveyor system. So we did another experiment to determine the mesh size by measuring the deposition view. This is this shows a final design of the deposition stage. The cathode. Was made by 32 by 32 mesh belts. Considering the slipping of the fabric against electrodes and removal, removing the general regenerative bubbles due to the water electrolysis. And for safety issue, all components included, including a mesh electrodes were electrical insulating through the non-conducting parts. This is, this RAS or robber, and you can see these plastic tunes around it. And one of the challenges of using conveyor belt electrodes would stable electrical connection from power supply to this moving mesh. So yeah. So this was address by electrical slip ring. So this is the electric slippery that connects the rotating rotating components of stationary white wire. So this inner part was embedded into the stainless steel rod and fix through the conductive epoxy. So that's coded with an updated policy. And also this rod, so this rod represents are presented in this schematic. The rod also serves as a tensional to press the whole fabric. Mesh belt downwards. And this is the Figaro pile line. The full pipeline is about three meter long and 0.5 meter wide, having a precursor fabric rollers and deposition bath and motor to drive these conveyor electrodes and also just take a winder? Yeah. And it has also the drying staging, which is the longest part in this pilot line. So this is a top view or the deposition back. And it's capable of processing the fabric what we're up to like 12 inches. I guess I use most of the time. So I'm going to just briefly talk about this deposition kinetics. The meaning of this definition kinetic. The 3D printed a fixture was used for quantitative analysis for CNT deposition. It controls the deposition area and push the whole non-conductive fabric towards the cathode. So to get intimate contexts. Though, in the roll-to-roll manufacturing process, the time-dependent parameters and the batch process became more significant because it determines not only the film density, but also throughput speed and the whole manufacturing and rates that we had investigated. The deposition yield quantitatively by varying these processing parameter that's dependent on the time. So electrical field type DC or AC, and electric field strength or dispersion, concentration and abolition time, et cetera, et cetera. So I'm going to skip these two slides. And these actual the history of deposition kinetics. This, this is a experimental work about the deposition rate, right? Though that these data or processing primary conditions can be applied. On actual continuous process. Go Summarizing, we have constructed the pilot line considering the effect of slippage between February and electrodes and the effect of gravity or perforations are those working cathodes. And we have determined the mesh size to be 32 by 32 considering the fluent bubble is keeping due to our electoral system or deposition amount. And we, we actually have to do more work on the deposition kinetics curve for better quality quality data histories. And the rest of the future work will include the dispersion concentration Fitbit system, which can replenish the fresh charge a carbon nanotube particles, so it actually maintain the stable dispersion concentration within a deposition chamber. We have to monitor that concentration through measuring the electrical conductivity. And we might need February tension or to keep the proper context fabric against the electrodes and drying stage where the heating units, though, any good ideas, are welcome to choose economical setup for our future work today. So thank you for listening. And this project was supported by National Science Foundation and unit L Brands. And I especially thank for afterthoughts instance for his guidance and Dr. writer from DSD in Australia and all group members and colleagues in CCM, especially Sagar omit theta and brain and top. Everybody. Navigate. And staff at Center for composite materials. Thank you very much. Questions. We have time for 11. Quick question. If someone has and after that, you have, you can contact the authors separately if you have additional questions. There's a question in chat for your day on NYSE, read it out to you. There. Do you think of any simulation or modeling on deposition kinetics that may help you with designing the experiment. Beth, I drew a good question about the deposition kinetics. So in this IEP process, it's actually composed of two different consecutive process. Migration of carbon nanotube, an actual coagulation of deposition on the electrode, right? There are many theories or studies about these electrophoretic mobility. We call it mobility, because it's actually describing the movement or velocity of the particles in a solvent. But there are too many processing parameters are too complex or specific to apply on our system. For example, the traditional electrophoretic mobility is directly proportional to the linear electric field, but that cannot actually applied on my system because the particles are not spherical. There are linear or like rope-like structure. A carbon nanotube or carbon nanotubes are very, very conductive, which we can see the high conductivity through the particles. But traditional electrophoretic deposition was applied on a non-conductive inorganic materials. So those actually, this is too complex to actually simulate and predict how much carbon nanotubes or will be deposited on the surface. There are one good model which is called hampers law. But that equation also have deposition efficiency factor, which is unknown vector and always have to be adjusted for specific systems. So I don't know. If you are willing to make assimilation for me. I'm going to get it. Right. So then can you stop sharing your screen? Oh yeah. So we'd like to thank professor tossed him something as research group for the wonderful dogs today. And Dr. toss in some data you want to make any closing comments I like and then advertise the next next talk next week's session. I guess I just want to mention that thanks to everyone for attending. And certainly if you have any questions, do feel free to contact any one of us. And we'd be happy to discuss far right and depth. Thanks again everyone for attending today and we'll see you again one week from today, same time. Next week we'll be covering talks on processes and modelling for advancement area systems. So using buy it all it says for re-coloring fibers in the recycling process or mechanical analysis of polymers, my data systems far using phase field modelling. So we have interesting topics and we look forward to seeing you again next week. Thank you so much. Thank you, sir.
Multifunctional Nanocomposites
From Kristen Scully April 16, 2021
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