By T’Jae Gibson ARL Public Affairs
Army researchers are forging new paths in material development to bring to Soldier equipment and supplies tougher than steel, from materials that don’t yet exist.
As part of a 10-year program involving partners from universities and industry, Army Research Laboratory scientists are investigating novel approaches that will result in the development of new classes of materials to protect Soldiers, their warfighting and communication equipment and the combat vehicles they rely on to get them in and out of warzones. Building upon expertise in coupling materials together to arrive at the best soldier solutions like ballistic vests and helmets, the ARL-led collaborative research team is forging a new path to develop new materials. They’re taking unprecedented approaches to examine materials. They will design the atomic level structures down to the crystal and molecular level to create transformational materials that will be used in future uniforms, electronic devices, armored vehicles and anything else Soldiers touch, or touch Soldiers.
When researchers achieve this understanding, Soldiers could then be outfitted with 30 percent lighter weight, more robust but less cumbersome protection equipment; weapon systems that have five to 10 times their current energy output; 30 percent more battlefield power; and electronics with 30 percent longer battlefield lifetimes. These improvements will free up Soldiers to focus on devastating the enemy’s willpower and ability to act.
This program requires Army scientists to model and examine materials in extreme environments.
“To make things harder, we want to see them (the materials) while they are exploding, or being blasted, or being hit by armor piercing projectiles, or being used as a battery — not an easy task but an exciting one,” said Dr. John Beatty, who manages ARL’s Materials in Extreme Dynamic Environments Collaborative Research Alliance.
Under Beatty’s watch, the alliance will build the capability to design revolutionary materials for protecting Soldiers.
“No longer will we take materials ‘off the shelf’ to put into armor systems. Instead materials will become an integral part of the design process itself,” he said.
To complement ARL’s expertise in protection materials, modeling, high strain rate characterization and computational tool development, ARL named Johns Hopkins University as the lead research organization of its external collaborative research team looking at materials in extreme environments, like the environments found when personnel and vehicle armor systems protect the Soldier from projectiles or explosions. Major partner institutions include the California Institute of Technology, the University of Delaware and Rutgers University.
This multiscale modeling approach is also being developed by ARL to facilitate transformational electro-optical, electrochemical and electronic materials for enhanced battlefield sensors and power applications for the Soldier.
“By developing validated multiscale models across the relevant scales, we gain new insight into which combination of atoms within a material result in the desired electronic properties,” said Dr. Meredith Reed, who manages ARL’s Multiscale Modeling of Electronic Materials Collaborative Research Alliance. To complement ARL’s expertise in electronic materials, modeling and computational tools, ARL named the University of Utah as the Lead Research Organization of this external collaborative research team that’s researching Multiscale Modeling of Electronic Materials. Major partner institutions include Boston University, and Rensselaer Polytechnic Institute.
Recent significant advances in experimental and computational capabilities and technology are helping them “address this challenge with an exceptional likelihood of success” said Dr. Peter Plostins, ARL’s former director of Enterprise for Multiscale Research in Materials. “The key is to be able to model large problems at and across material scales as well and validate the modeling effectively.”
Plostins retired from ARL in December 2013.
Last spring, ARL’s supercomputing capability topped 1.1 petaflop capability, meaning it can crunch a quadrillion floating points per second. By fiscal 2016, it will have more than four times that capability. Real-time nuclear magnetic resonance imaging during surgery or even astrophysical simulation can be performed with this kind of capacity, for example.
“New and sophisticated experimental methods have been brought on line by the Department of Energy such as the Advanced Photon Source at Argonne National Laboratory which will enable real time dynamic interrogation of material phenomena at the nano second time scale at micron and below length scales. Advances like these have opened the door to realizing a materials modeling and interrogation capability that is unprecedented and is the key to realizing a true ability to design materials,” Plostins said.
Under the Enterprise for Multiscale Research of Materials effort, researchers will demonstrate a comprehensive “materials-by-design” capability for protection, electronic and energetic materials that start with multidisciplinary and multiscale modeling. “I need to model the material with the correct physics to optimize it.”
Researchers will then design and optimize the material at each scale and across scales to reach the desired material performance. Those performance parameters will then be described and defined as part of a characterization and properties analysis step. Finally, all of these models must be validated at each scale, through detailed and complex experiments.
“In the end, the Army needs to make what it desires to have for the Soldier,” Plostins said.
Experiments will help Army researchers discover what should be modeled and at what scale, and eventually prove those models work and reflect reality.
small amount of a material and subject it to very high pressures squeezing it between two diamonds,” said Beatty. He said the pressure they exert is at 300 gigapascals and above, which is in the range of pressures seen when a high explosive material detonates, or when an armor system gets hit in the field.
“At the bottom of the Marianna’s trench, the deepest part of the ocean, the pressure is about 0.1GPA so we’re 3,000 times more than that. But it’s not enough to expose it to the pressure,” Beatty said. “We use several methods to examine the material while it is under such high pressure, such as Raman spectroscopy and various forms of X-ray spectroscopy. From this we can figure out quite a bit about what is changing in the material at these high pressures. We can use this information to validate models that are built up from quantum mechanics to describe these materials. It’s a very important step in our quest to design materials for these extreme environments.”
ARL is also using a specialized apparatus known as a Kolsky bar to examine materials loaded up really fast with lots of mechanical energy.
“In armor systems, protection materials are struck with a lot on energy in a small spot. Our enemies hope that that energy can basically go right through the armor system and damage the innards, and yes, that also means wounding or killing our Soldiers inside. So we need to be able to examine materials when we load them up with energy real fast!”
“We send a high stress pulse down a solid metal bar, then smash a sample between that bar and another one, and then examine the stress pulses that result. And those stress pulses tell us a lot about what happened to the material we were smashing,” Beatty said.
Although the technique is not new, ARL is changing how the Kolsky bar is used.
“Until recently, the systems we used were kind of limited into how fast they could deform or smash the materials we were looking at,” he said.
An ARL team led by Dr. Dan Casem has worked to modify instrumentation used on the bars, which are typically as big around as the handle on a baseball bat. With the new optical instrumentation from ARL, the bars can now be made as thin as some human hairs. By making the bars smaller, researchers can actually smash them in a way to get even higher deformation rates, at orders of magnitude greater than before, making the extreme environment during the test much more realistic.
ARL’s work with Johns Hopkins University and Argonne National Lab is also using similar high strain-rate tests with even more advanced diagnostics. They’re using the Department of Energy’s beam line to produce short pulse, high-energy X-rays during these experiments.
“These X-rays will allow us to take snapshots of many things going on inside the materials we are testing, such as phase changes, defect changes, etc.,” Beatty said. These experiments are needed to peer inside these materials during the experiments to validate the multiscale models that the ARL team is building from the atomic level up.
“We need these advanced techniques to both discover what we need to model, as well as to validate those models, to make sure they are real. Experiments matter and are critical to expanding our abilities to design materials,” Beatty said. “The experimental capabilities of the Army’s Rodman Materials Laboratory at Aberdeen Proving Ground will be critical in achieving our goals.”
Protection materials go invisible
ARL’s bottom-up design and fabrication of highly complex multifunctional materials with new and unprecedented properties has researchers looking at negative index composites with optical cloaking properties, which could one day mean rendering certain materials invisible.
The Army is only a couple of years away from developing technology that essentially will lead to making things, even people, invisible. Groundbreaking research in transformational
optics leveraged by the Army Research Office, an ARL directorate based in Triangle Research cloaking effects, or the ability to hide objects when viewed from a wide range of directions and in visible light.
But the Army is not ready to put invisible Soldiers or systems on the battle space, said Dr. Richard Hammond, a theoretical physicist in Optical Physics and Imaging Science Divisions — at least, not yet.
More promising though are less superhero-like scientific applications of metamaterials that will undoubtedly grow America’s military superiority by leaps and bounds, said Dr. David Smith, associate professor and Augustine scholar with Duke University’s Electrical and Computer Engineering Department. He’s also the director of Duke’s Center for Metamaterials and Integrated Plasmonics.
Smith said those applications include creating microscopic lenses out of meta-materials that can zoom to the micron level, making it possible to spot germs, chemical agents and even DNA using basically a pair of binoculars. Similar lenses could focus even a tiny amount of ambient light and use it as a power source. This would be great for the battlefield; a Soldier could see a cloud coming and suspect chemical or biological warfare agent threats but with the new meta materials being developed, that Soldier will have the ability to see things smaller than the wavelength of light and can pick up on signs of pathogens and viruses with any visual device like night vision goggles or sensors.
“Metamaterials are artificial materials engineered to provide properties which may not be readily available in nature. These manufactured properties are versatile and can be tailored to fit almost any practical need, enabling them to go beyond the capabilities of natural materials, including control of the light at an unprecedented level,” Smith said.
The primary research in metamaterials investigates materials with negative refractive index, or a ratio of the speed of light as it passes from one medium to another. Negative refractive index materials appear to permit the creation of superlenses, which resolve images ARL’s computational scientists play a part in this research as well. High-performing computers like those housed within the Defense Supercomputing Resource Center that ARL manages on Aberdeen Proving Ground, Md., get the Army closer to solving the hard-to-solve mysteries of our time.
The proof of principle was managed and funded by the Army Research Office, who oversees a multi-university research initiative involving Purdue University, the University of Colorado, the University of California-Berkley, Princeton University and Norfolk State University that are performing work in transformational optics.
“We are re-writing the books on optics, who knows what we will see in the future,” Hammond said.
ARL is part of the U.S. Army Research, Development and Engineering Command, which has the mission to develop technology and engineering solutions for America’s Soldiers.
RDECOM is a major subordinate command of the U.S. Army Materiel Command. AMC is the Army’s premier provider of materiel readiness — technology, acquisition support, materiel development, logistics power projection, and sustainment — to the total force, across the spectrum of joint military operations. If a Soldier shoots it, drives it, flies it, wears it, eats it or communicates with it, AMC provides it.