 In a big room full of machinery, an Army researcher starts an application on his computer and a 3D printer starts worrying and moving. This is the U.S. Army Combat Capabilities Development Command's Army Research Laboratory at Aberdeen Proving Ground, Maryland. The laboratory has essential research programs to help build the Army of the Future. 3D printing, also known as additive manufacturing, will play a critical role in changing how we build things. My name is Jason Robinette. I'm the program manager for ARL's Essential Research Program for the Sciences of Additive Manufacturing for Munitions. Jason took me on a tour of his additive manufacturing facility. This is where the magic happens, where powders become stronger than steel, where parts, and even circuit boards, are created from the nozzle of a printer. This is a chemistry lab, and the reason our printers are in a chemistry lab is because we're 3D printing polymers. One of the challenges with 3D printing is because we're building a part layer by layer instead of casting it and extruding it, like traditional polymer parts. We really have to pay attention to the way the layers interact with each other as you're building the part. If you don't get good wetting, good adhesion, your part typically suffers in terms of its mechanical performance. I sat down with Jason to discuss advancements in additive manufacturing. The good, some disadvantages, and the use of 3D printing as a complement to existing and traditional manufacturing methods. I've been at ARL for roughly 14 years. I received my bachelor's degree from the University of Delaware. When I was at Delaware, I had the opportunity to intern in our materials division for three summers. I really enjoyed the facilities here, the people, the work that I was doing, after that inspired me to get my doctorate degree at Drexel University. Both degrees are in chemical engineering. In grad school, my focus was on polymer and composite design, along with the interfaces that go along in composites. I continued that work as a postdoc. I was able to make my way back to ARL to do the postdoc, where I focused those skills in polymers and composites on lightweight vehicle armor. So early after I transitioned over to a federal employee, I started switching gears and focusing more on energetic applications and how can we use polymers in new ways for energetics to get better performance. And that sort of led me into the ERP, where I built our program at ARL for energetics additive manufacturing, which is one of the main thrust areas for the ERP. And recently, within the last several months, I took over as program manager. As the essential research program manager, please tell me what the primary goal of this ERP is. Addive manufacturing, also known as 3D printing, is a revolution in the manufacturing world in that it fundamentally changes the way that we build things. Now it's a layer by layer fashion, as opposed to casting or molding parts in traditional methods. And really this layer by layer building of parts opens the door for the creation of geometric designs never thought possible. Since its inception in the 1980s, additive manufacturing has advanced significantly in terms of the feedstock materials, moving from cheap polymer plastics to now high performance polymers, expanding into metals and ceramics. In terms of processing science, the first 3D printers were very slow, so it would take a long time to build a part. And really because of the deficiency in materials and the processing speed, 3D printing was really only viable for rapid prototyping of new geometric designs. But with the advances in manufacturing and material feedstocks, we could start to envision additive manufacturing as the best way to start making materials and parts. How does this fit into the lab's essential research program? We've had all these recent advances in additive manufacturing. They want to see how we can harness those advances into what's going to be most impactful for the Army. So we're focusing additive manufacturing for munitions to strategically target Army modernization priorities within long range precision fires and next generation combat vehicle. On a component level, we've selected specific targets within a munition that we think would be the lowest hanging fruit in terms of transition. If you want to think about these components in terms of the propellant, we think we can print it in a way that we get higher muzzle velocity, which yields longer range. In terms of the metals, we think we can be more efficient in the way that we make and print the warheads to give it more lethality. And then in terms of the electronics, we think we can print them to better withstand harsh environments, more specifically, high gravitational forces. High G forces is what we envision future munitions experiencing. We think we can print the electronics in a new way to better withstand the high G forces. And also, we think we can print it more efficiently to save space and weight within the munition. Talk to me about some of the problems that you're trying to solve under this ERP. Okay. Historically, the downside of additive manufacturing is that the printed parts don't retain the same mechanical performance or the mechanical properties of traditionally manufactured parts. So if you envision the future force and needing to survive higher G environments, mechanical properties are going to be really important. So naturally, this is a problem with 3D printed parts. But now we're asking not only to maintain the properties of a part compared to traditionally manufactured items, it's actually improving it. So in the ERP, we have strategies in place to optimize both feedstocks of metals, ceramics and polymers for improved adhesion from a layer to layer adhesion and improve microstructure that will yield optimal properties and address concerns and give us strategies to actually improve mechanical properties of the part. Once we solve those problems, we can start incorporating design tools in such a way to yield never seen before geometries for munition components. We can print propellant with higher density, more energy, and designs to optimize gas flow rates, pressurization and thrust profiles. We can print more mass efficient warheads that have increased lethality. And then we can target to optimize munition electronics and improve the reliability through simultaneous design and additive manufacturing of structured circuits and fusing. What are you planning to demonstrate with the short and long term goals? In the short term, we'd like to demonstrate first the viability of additive manufacturing on a component level within munition. This means better combustion for propellants, more mass efficient warheads with increased lethality and optimized circuit and fusing designs on conformal surfaces. Munition electronics are basically two dimensions on very flat substrates. We're trying to print on different surfaces in the munition, which means they'll be curved and non-planar. Longer term, we want to start integrating all of the technologies and printing. So that's hybrid, metal, energetics. Start integrating together on a system level to see if we can get synergy between the different manufacturing techniques. So if you envision in the future, I could start printing the energetics with the metals, seeing if there's a benefit in terms of the adhesion of the material, of the rocket motor to a metal casing, help with structural reinforcement, and then taking it even a step further. Can I start integrating electronics and fusing so that I more efficiently ignite either propellant or explosives? So help listeners clarify the capabilities that fall under this particular essential research program. So in terms of capabilities, the reason that the term science is in the name of the ERP, so Sciences for Added Manufacturing Munitions, is really developing the core capability to customize our feedstocks to print the materials we need. The Army demands certain material properties for particular applications. So we want to develop the capability to print our own materials, and in turn, that's going to mean we need to develop the capability to adjust our printers, so to build more custom printers. I think most people that get into the 3D printer space, they get a commercial printer, they're relying on commercial feedstocks. We want to go the other way. These are the feedstocks we want because we know they're going to give us the properties we need, and it's being able to adjust those feedstocks and adjust the processes to be able to build the parts. Perfect lead-in to the next question, which is the structure. How is the structure of the ERP organized based on the objectives that you want to achieve? We have three teams to hit all of the munition technologies in this ERP. The teams are the Energetics, Metals, and Hybrid additive manufacturing. Underpinning these core teams is our design science team, and what this team does is it brings together the manufacturing with the geometric design to really provide the driving force for additive manufacturing, answering the essential question, why do 3D print this? By the nature of our research, we're very collaborative, multidisciplinary, so you'll see a lot of collaborations internally within ARL. For example, we have our Metals team coordinating with our munition design, or with our warhead design folks. For Energetics printing, we have our Polymers additive manufacturing team strongly collaborating with Energetics synthesis and formulation for explosives and propellant. On the Hybrid team, this is very cross-directorate where we're bringing in subject matter experts from our sensors and electronic directorate to start working with our materials division and start seeing how we can better integrate the capabilities for circuit design while simultaneously addressing the materials issues all under that Hybrid AM umbrella. Where we can, we also look to leverage external research programs in industry and academia, other government agencies, through customer programs and congressional agreements. Being able to rely on outside partners can really help accelerate the progress of our research and actually bring some new ideas to the table. It's our idea to take these external concepts and capabilities and align them to feed into the ERP to really accelerate our progress. With that said, are there any highlights to mention or key work that's being done so far? One example is for our printer of Energetics materials. We adapted a commercial technology through a congressional we had with PPG Industries. They had a printer designed for other things, definitely not Energetics, but we saw that printer and we said it has the right processing capabilities to be able to handle the materials or the feedstocks that we were looking for. We've also worked with universities like UMass Lowell to help with surface science of some of our Energetics ingredients. We've worked with Purdue with improving the printer so we can decrease nozzle size and really print very small geometric features. Basically getting that Energetics printer up and running, it's been a really team collaborative effort with relying on CAs to feed that and get us started. Where we've taken it internally is exciting because this wasn't a printer designed for Energetics. We had to take the printer, redesign it to make it safe to operate and then also handle specific materials that we're interested in. That's on the Energetics side. In terms of the metals, some key highlights are we've printed the high strength steel in the world and we did it in a more timely and cost efficient way. What this enables is we can now look at this special steel for different munition components and we can quickly rapidly prototype it so we can really speed up the throughput of research and say, is this material worth looking at for this specific munition component? In terms of our hybrid team, we printed the world's first hybrid microcontroller circuit on a hemisphere that survived high Gs that are comparable with what munitions see today. We've already met goals with just our printer and our circuit design in terms of high G survivability. It's almost magical what can be done with 3D printing. How optimistic are you that this is going to change the world? Well, I think over the last decade is where, you know, it's what I talked about earlier. It's the advanced and the feedstocks we can print, the materials we can print and the actual, you know, equipment, the printers themselves have come a long way. So if we've come that long of a way in 10 years, you could envision, you know, the next 20 years us really, when we find that right combination of feedstock with printer and a lot of it comes down to feature size and then you need to connect it to the modeling so topology optimization is a relatively new field for this because it's telling us you should print it this way and that's where you start thinking about integrating the artificial intelligence and machine learning, integrating that all together, having the computers think for us could definitely make connections that we're not seeing now. What's the future potential of additive manufacturing? I think the potential is endless. I think in the ERP we're focused on more on near term goals to try to deliver a product and capability for the army to feed into some of those army modernization priorities. So yeah, the sky's the limit, but but I'm in the camp where I need to see it first before I'm going to sell it as the revolution that others are selling it now. What we learned today is a podcast about the science and technology behind the Army of Tomorrow. Please like, subscribe, and share to get the word out about what Army researchers are doing to make America's soldiers stronger and safer. In future episodes, we'll meet with other project managers of the lab's essential research programs and find out what they're doing to discover, innovate, and transition technology solutions to the soldier. Thanks for joining us. For the CCDC Army Research Laboratory, I'm Tracey Dean.