Military Technology Research

Başlatan Karabasan, Tem 25, 2019, 08:32 ÖÖ

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U.S. Army developing high-tech soldier batteries for changing character of war

Currently, local conflicts and war in Afganistan and Iraq has highlighted the importance of lighter batteries with more power and extended runtime for the Soldier.

A rifleman today requires an average of 12 watts of power in the form of AA and conformal wearable batteries. That means the weight requirement of batteries for a standard 72-hour patrol is about 28 pounds.

That includes batteries for such things as night vision goggles, weapon optics and communications devices.

Army Futures Command, or AFC, is helping to increase Soldier lethality and survivability through the research and development of lighter batteries with more power and extended runtimes, according to Dan Lafontaine, CCDC C5ISR Center Public Affairs.

As the Army modernizes the current force and prepares for multi-domain operations, the quantity and capabilities of Soldier-wearable technologies are expected to increase significantly, as will the need for power and energy sources to operate them.

Engineers and scientists at AFC's subordinate command -- the Combat Capabilities Development Command, or CCDC -- are making investments to ensure future power and energy needs are met by exploring improvements in silicon anode technologies to support lightweight battery prototype development.

"This chemistry translates to double the performance and duration of currently fielded batteries for dismounted Soldiers," said Christopher Hurley, a lead electronics engineer in the Command, Power and Integration Directorate, or CP&ID, of CCDC's center for Command, Control, Communications, Computers, Cyber, Intelligence, Surveillance and Reconnaissance -- or C5ISR.

"The capabilities of these materials have been proven at the cell level to substantially increase energy capacity. We're aiming to integrate those cells into smaller, lighter power sources for Soldiers," Hurley said. "Our goal is to make Soldiers more agile and lethal while increasing their survivability."

Soldiers currently carry an average of 20.8 pounds of batteries for a 72-hour mission. With the Army focused on modernization and the need to add new capabilities that require greater power, the battery weight will continue to increase and have a detrimental effect on Soldiers' performance during missions, Hurley said.

"The C5ISR Center is helping the Army get ahead of this problem by working on advanced materials like silicon anode," said Hurley, who noted that incorporating silicon-based anodes into Army batteries will cut their battery weight in half.

The C5ISR Center is incorporating component-level R&D of advanced battery technologies into the Army's Conformal Wearable Battery, or CWB, which is a thin, flexible, lightweight battery that can be worn on a Soldier's vest to power electronics. Early prototypes of the updated silicon anode CWB delivered the same amount of energy with a 29 percent reduction in volume and weight.

The military partners with the commercial power sector to ensure manufacturers can design and produce batteries that meet Warfighters' future needs. However, the needs of civilian consumers and Warfighters are different, said Dr. Ashley Ruth, a CP&ID chemical engineer.

The Army cannot rely on the commercial sector alone to meet its power demands because of Soldiers' requirements, such as the need to operate at extreme temperatures and withstand the rigors of combat conditions. For this reason, the electrochemical composition in battery components required for the military and consumer sector is different.

"An increase in silicon content can greatly help achieve the high energy needs of the Soldier; however, a great deal of research is required to ensure a suitable product. These changes often require entirely new materials development, manufacturing processes and raw materials supply chains," Ruth said.

"Follow-on improvements at the component level have improved capacity by two-fold. Soldiers want a CWB that will meet the added power consumption needs of the Army's future advanced electronics."

As the Army's primary integrator of C5ISR technologies and systems, the C5ISR Center is maturing and applying the technologies to support the power needs of the Army's modernization priorities and to inform requirements for future networked Soldiers. This includes leading the development of the Power and Battery Integrated Requirements Strategy across AFC, said Beth Ferry, CP&I's Power Division chief.

As one of the command's highest priorities, this strategy will heavily emphasize power requirements, specifications and standards that will showcase the importance of power and energy across the modernization priorities and look to leverage cross-center efforts to work on common high-priority gaps.

Power Division researchers are integrating the silicon anode CWB with the Army's Integrated Visual Augmentation System, or IVAS, a high-priority augmented reality system with next-generation capabilities for Solider planning and training. Because IVAS is a dismounted Soldier system that will require large amounts of power, the Army is in need of an improved power solution.

To gain Soldiers' feedback on varying designs, the C5ISR Center team plans to take 200 silicon anode CWB prototypes to IVAS Soldier Touchpoint 3 Exercise in July 2020. This will be the first operational demonstration to showcase the silicon anode CWB.

The C5ISR Center is finalizing a cell-level design this year, safety testing this summer, and packaging and battery-level testing taking place from fall 2019 to spring 2020. Advances in chemistry research can be applied to all types of Army batteries, including the BB-2590, which is currently used in more than 80 pieces of Army equipment.

"A two-fold increase in capacity and runtime is achievable as a drop-in solution," Ruth said. "Because of the widespread use of rechargeable batteries, silicon anode technology will become a significant power improvement for the Army." Mesajı Paylaş
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We Now Have The First-Ever Permanently Magnetic Liquid, And It's Absolutely Trippy

What has the magnetic properties of a solid magnet, but the mechanical properties of a liquid? If you answered 'nothing,' you're wrong - because engineers have just created just such a substance, by using a modified 3D printer.

Yes, ferrofluid is already a thing, but this is different. Unlike the ferrofluid you may know and love (because come on, it is awesome), the new magnetic liquid retains its magnetism even in the absence of an external magnetic field.

"We wondered, 'If a ferrofluid can become temporarily magnetic, what could we do to make it permanently magnetic, and behave like a solid magnet but still look and feel like a liquid?'" said materials scientist and engineer Tom Russell of the University of Massachusetts.

"We've made a new material that is both liquid and magnetic. No one has ever observed this before."

It's pretty similar to ferrofluid, actually. Both consist of ferromagnetic nanoparticles suspended in a fluid. The new magnetic liquid uses iron oxide nanoparticles, which is also a popular choice for ferrofluid, so there are no surprises there.

But last year, the team developed a technique for 3D-printing structures out of liquid. It used two liquids: water injected into a tube of silicone oil mixed with a nanoparticle surfactant that forms an elastic film, essentially holding the water in place.

This is what the team decided to use for their nanoparticle suspension, printing droplets just one millimetre in diameter. The iron oxide nanoparticles crowded towards the surface of the droplet, forming a shell at the interface between the water droplets and the oil suspension. This is called interfacial jamming, and it's a well-known nanoparticle behaviour.

Then they placed the droplets near a magnetic coil to magnetise them. Just like ferrofluid, the iron oxide particles were attracted to the magnet. So far, so normal.

But when the researchers moved the magnetic coil away, it got less normal. When ferrofluid is removed from the presence of a magnetic field, the nanoparticles fall into disarray, and the fluid just becomes sort of blobby.

But with this new liquid, the nanoparticles started spinning towards each other in unison, like synchronised swimmers, or "little dancing droplets," according to engineer Xubo Liuof the Beijing University of Chemical Technology. They had retained their magnetism.

"We almost couldn't believe it," Russell said. "Before our study, people always assumed that permanent magnets could only be made from solids."

Upon further investigation, the team found that exposing the liquid to a magnetic field causes the magnetic poles of the nanoparticles to align in the same direction. But when the magnetic field is taken away, there's no room for the surface particles to drift because they're jammed so closely together, and thus stay that way.

The mysterious part is that they somehow transfer their magnetism to the nanoparticles free-floating inside the droplet. The team doesn't yet know how that happens. But it does, and the entire droplet just stays magnetised.

"What began as a curious observation ended up opening a new area of science," Liu said.

And, even more curiously, the liquid can change shape - standing tall as a cylinder, flattening out like a pancake, round like a sphere, thinning out like a wire, or even more complex shapes, like… octopuses.

The invention can be controlled by an external magnetic field, which opens up possibilities in soft robotics, artificial cells, and perhaps even targeted drug delivery. Not to mention the things to be learnt from trying to figure out how the floating droplets magnetise.

"This opens the door," Russell said, "to a new area of science in magnetic soft matter."

The research has been published in Science. Mesajı Paylaş
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Explosives such as TNT are highly toxic to produce. That's why the Lab is designing safer, greener replacements.

Construction on the West Virginia Ordnance Works factory began in March 1942. The factory spread across more than 8,000 acres on the east bank of the Ohio River, about six miles north of Point Pleasant, West Virginia, tucked between the pines and maples. Eight months later the factory was producing 720,000 pounds of trinitrotoluene (TNT) every day for use during World War II.

The process of making TNT uses toluene, a solvent most commonly found in paint thinners; as well as nitric acid, sulfuric acid, and oleum oil--all caustic chemicals. The combination is washed in warm water and soda ash, then cold water, leaving behind massive pools of what's called red or pink water--a 93 percent sulfuric acid liquid that's clear, oily, and toxic. By the time the government closed the factory, six days after dropping Fat Man over Nagasaki in August 1945, 39 of these acidic ponds remained. Remediation workers had to "flash" all the equipment with a quick burn to rid it of chemicals. Ten pipelines that carried TNT to and from various buildings were removed.

The factory was mostly forgotten . . . until 1981, when locals noticed toxic pink water seeping from a sulfur pond into a creek. The Environmental Protection Agency (EPA) listed the location as a Superfund site, and the government has worked ever since to rid the area of contamination.

The West Virginia Ordnance Works factory produced TNT, which was vital to helping the Allied Forces win World War II. But the chemicals used to create the explosive have left a toxic burden. Photo: U.S. Army Corps of Engineers.

Even after advances in production safety since World War II, making TNT still leaves behind hazardous chemicals. The United States produces millions of tons of the explosive every year, not just for military uses, but also for the construction, demolition, and mining industries. On military land alone, the Army estimates 1.2 million tons of U.S. soil are contaminated from the production and use of TNT, which the EPA considers a possible carcinogen. And because TNT leaves a 2 percent chemical trace anytime it explodes, contaminated sites aren't limited to active and shuttered processing plants. On any bombing range and anywhere artillery is fired, grenades are hurled, or a weapon using TNT is detonated, small amounts of toxic residue are left in the ground.

It's not likely the United States' demand for an inexpensive, dependable explosive will lessen anytime soon. So it's no surprise that developing a safer, greener alternative to TNT has become something of a Holy Grail quest--one that Los Alamos explosives chemist David Chavez was able to complete.

Three years ago, Chavez, answering a call from the Department of Defense, set out to develop a more eco-friendly replacement for TNT. What he created contains none of the dangerous chemicals found in TNT and leaves no toxic byproducts behind. And it's 50 percent more powerful.

Explosives history

German chemist Julius Wilbrand accidentally invented TNT in 1863. He was trying to develop a powdery yellow clothing dye, and it took another 30 years before the world realized his invention's potential as an explosive. Then came World War I. The Germans were the first to widely use TNT, filling their armor-piercing bombs with the new material. By World War II, TNT was standard in nearly all military explosives.

The next development came around 1940, when the British created RDX, another high explosive, which packed one-and-a-half times the energy of TNT. America honed the RDX manufacturing process and was soon producing 500 tons a day to fill the weapons carried to Europe during World War II--bazookas, "dambuster" explosives, and other massive bombs dropped from planes. To this day, most military weapons around the world use an RDX and TNT combination, called Comp B. The problem is that RDX production also involves the synthesis of toxic chemicals the EPA has termed likely carcinogens.

The hammer test

This is where Chavez's groundbreaking science comes into play. Chavez's office occupies a squat building in a quiet corner of Los Alamos National Laboratory. And it was here, in his lab of glass beakers and flasks, that he first thought of and created BOM--bis(1,2,4-oxadiazole)bis(methylene) dinitrate. BOM meets all the requirements of a TNT replacement: it's relatively inert, meaning it won't blow up easily. You can drop it on the ground and it won't detonate. And using heat, it can be converted into a liquid, then poured into any-shaped weapon, where it solidifies--a property known as being melt castable.

BOM--bis(1,2,4-oxadiazole) bis(methylene) dinitrate--is twice as powerful as TNT and leaves no toxic trace. BOM is melt castable: it can be converted into a liquid, poured into any shape, and will solidify.

Most importantly, BOM has no sulfur waste-water problem. "There's hardly any heat in the process at all. And by eliminating the heat, you avoid the degradation products, which are toxic," Chavez says. "It actually takes very mild reaction conditions to make BOM."

Both BOM and TNT contain carbon, oxygen, hydrogen, and nitrogen atoms. But the difference lies in BOM's synthesis process--only four relatively easy steps. First, Chavez dissolves a chemical in a solvent, boiling the two together. He waits for the mixture to cool, filters the byproduct, and then mixes the leftovers with another solvent. This is repeated three times with different chemicals until the last step, which involves reducing the mixture's temperature until…voila! You have a fine, white explosive powder.

The molecular difference between TNT and BOM comes from replacing two carbon atoms with nitrogen atoms. This boosts the combustion rate and makes the explosive burn cleaner. "This material has a much better oxygen balance," Chavez says, "so its fuel is more likely to be burned completely. And anything that's unreacted would degrade relatively easily in the environment." The new synthesis also made the molecule denser, another factor in why it's 50 percent more powerful than TNT. It's melt castable, and doesn't require any mixing with RDX to create an explosive with the same output as Comp B. BOM alone is enough.

The BOM structure spelled out in powder.

Besides being more environmentally friendly and more powerful, BOM is also safer to handle. As way of demonstrating, Chavez kneels on the ground and prepares to perform what is called the hammer test.

"I think I like this hammer better," says Chavez, as he trades a mallet for a ball-peen. "It's smaller." He leans forward and places less than a one-eighth of a teaspoon of BOM on a metal block.

"Cover your ears," Chavez says.

He smacks the hammer down and… nothing. So he packs the powder a bit more densely, then places one hammer directly atop the BOM and taps it with another. The tiny explosion echoes in the lab and down the hallway. A slight trace of smoke rises. What the simple test proves is that BOM needs deliberate action to detonate--it's very safe but still packs a lot of energy.

The hammer test is just one of many tests experimental explosives undergo at the Lab. This way, scientists have a good understanding of what they're working with. Some of the tests involve fancy, high-tech machines. Others, like the hammer test, are much more analog: dropping a weight from various heights on an explosive or holding a barbecue lighter to a small amount of the explosive.

BOM isn't the only green explosive being developed by Los Alamos. Laboratory scientists are also working on a more environmentally friendly high explosive for use in nuclear weapons.

But why worry about making a high explosive in a nuclear weapon environmentally friendly?

Even if a weapon is never detonated, the Lab's mission includes ensuring the safety of the nuclear stockpile, which involves testing new and old components and updating them as necessary. That requires the production of PBX (plastic-bonded explosive) 9501 and 9502--the high-explosive materials used inside the weapons. PBX is made in large quantities at the Pantex Plant in Amarillo, Texas. Like TNT, the current PBX explosives require mixing caustic chemicals, which creates a risk to the chemical engineers producing the explosive and leaves behind toxic waste.

Los Alamos scientist Elizabeth Francois and Chavez collaborate on many projects (throughout the BOM process they were constantly bouncing ideas off one another). Chavez came to the Lab in 2003 from Harvard University, and Francois came five years later, from the University of California, Berkeley. In 2008, they both started toying with a new PBX formulation.

Most high explosives require nitration, the chemical process of introducing nitrogen into a molecule. This step almost always involves acidic chemicals. Even BOM has a nitration process; it's just a milder form than most. But the new process Francois and Chavez developed doesn't. It has only an oxidation process. This allowed them to consider much milder chemicals, the result being that they were able to create an explosive called diaminoazoxyfurazan (DAAF) using common ingredients, such as baking soda. It also meant the byproduct waste was nontoxic. "It's essentially salty water," Francois says.

An additional benefit of DAAF is that because it can be ground into smaller particle sizes, it can have increased shock sensitivity, which means it can be used in all parts of a nuclear weapon: in detonators, as a booster, and/or as the explosive, which compresses a plutonium pit.

Francois developed a plastic bonding process for DAAF so it could be shaped and pressed into pellets, which makes it safer for handling. Once Francois figured this out, PBX 9701 was born--the first new PBX developed in four decades.

Francois, Chavez, and their team are already synthesizing PBX 9701 in the tens-of-kilograms level. In a few years it could be produced at the hundreds-of-kilograms level at the Pantex Plant.

BOM could also follow this path, but its future is less certain.

In October 2019, BOM was a finalist for an R&D 100 Award--an "Oscar of Invention." This designation could help attract some much-needed publicity. If there's interest in developing BOM, Chavez says, "The typical lifetime of a new molecule from discovery to production tends to be 15 to 20 years because of all the testing and searching for funding to develop the molecule."

"If we had enough money, though," Francois points out,"we could probably do it in five years."

BOM can be made in four relatively easy steps. And it's not only better for the environment, it's also safer for the chemists (such as David Chavez, pictured) working with the molecule.

A greener future

The U.S. Army Corps of Engineers surveys the environment at the West Virginia Ordnance Works site every five years. The last review, completed in 2016, found that after 71 years, TNT still contaminated the soil at the site. At the TNT manufacturing area, now only a cement foundation, surveyors found nitroaromatic contamination in the groundwater. The steel and clay sewer lines leaving the factory floor were also still contaminated, as well as the three reservoirs that once held 30 million gallons of red wastewater.

The latest round of remediation involved replacing warning signs around the site. Two-foot-thick soil covers contaminated dirt. Depressions were leveled where polluted water had pooled. And the Army Corps continues to pump groundwater through filters to stop contamination from seeping into the water table.

All of this is expensive. Remediation at the Ordnance Works site alone has cost the government $96.3 million so far, with about $70 million more budgeted for the future. Of course, there are many more sites contaminated by TNT all over the country, including Camp Minden in Louisiana, the Apache Powder Company site in Arizona, Joliet Army Ammunition Plant in Illinois, and Bangor Naval Submarine Base in Washington.

BOM can't change what's already been done. But it can ensure that processing sites don't become health risks to humans or ruin the environment. So in the future, places like the West Virginia Ordnance Works facility might not be thought of as burdens to clean, but remembered as the places that helped win the wars that kept the nation safe.

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Military-spec filament produces stronger 3D-printed objects

While consumer-grade 3D printers may be adequate for making things like models or curios, they're not always up to the task of creating objects that stand up to real-world use. That could be about to change, though, thanks to a new printing filament.

Compact, inexpensive 3D printers typically utilize a process known as fused filament fabrication (FFF). This involves heating a plastic filament to its melting point, then extruding it through a nozzle. Successive layers of the molten plastic are deposited one on top of the other, forming a single solid object as they cool and fuse together.

According to US Army engineers, though, items printed in this fashion tend to be too structurally weak for rough-and-tough use by soldiers in the field. This is a shame, since if troops were able to carry small, cheap 3D printers with them, they could make parts and tools onsite as needed. And although there are printers that use non-FFF techniques to produce stronger objects, those machines are large and costly, making them impractical for field use.

The initial cylinder of material, which is itself 3D-printed (a), the thermal draw tower, which heats that material and draws it out (c), and a cross-sectional view of the resulting filament (e)

Led by Dr. Eric D. Wetzel, researchers from the Army's Emerging Composites team set out to address this problem. They ultimately created a new dual-polymer filament that allows consumer 3D printers to produce much stronger items, utilizing their existing FFF hardware.

The material starts out in the form of a cylinder with a star-shaped polycarbonate core, that's surrounded on all sides by ABS (acrylonitrile butadiene styrene). Utilizing a proprietary device called a thermal draw tower, that cylinder is heated and drawn out into a thin filament.

Once that filament cools, it can be wound onto a reel and then used in an ordinary FFF 3D printer. Objects printed from the material are subsequently heated in an oven and then cooled, ensuring that the two polymers thoroughly fuse together.

In lab tests, such objects proved to be much stronger than those made from conventional filaments - in fact, they exhibited mechanical properties similar to those of identical items produced via commercial injection molding techniques. The material's annealing (heating and cooling) time currently sits at 24 to 48 hours, but the team hopes to reduce that figure to four hours or less.

The Army is now looking for industry partners who may be interested in commercializing the technology, for use beyond military applications.

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Wireless Communication Network and Microelectronics


UWB Circuits and Sub-Systems for Aerospace, Defence and Security Applications (Published: July 26th 2019)
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US Army programme blends cyber with traditional EW

Lockheed Martin is set to expand its work on the US Army's Multi-Function Electronic Warfare Air Large (MFEW-AL) programme, with the aim of combining EW and offensive cyber capabilities in a single platform.

MFEW-AL is a podded system designed for use in Group 4 UAS, along with other airborne platforms.

It represents 'the first airborne opportunity for the army to combine the extensive capabilities that exist and are being developed in the cyber domain, with the more traditional capabilities in the classical EW domain', said John Wojnar, director of cyber/EW convergence strategy at Lockheed Martin.

The pod combines the types of ESM the company has developed for other airborne platforms, such as the B-2 bomber or Black Hawk helicopters, with its growing focus on cyber, Wojnar explained to Shephard.

Phase One of the programme was an 18-month contract that Lockheed Martin won in September 2018, and which concluded with a flight test in January 2020. The latest project agreement will see the company build operational pods and pursue technological advances in a number of areas, Wojnar said. This builds on the first phase, with research focusing on antenna technology, the incorporation of additional cyber techniques, and more.

Lockheed Martin's work on MFEW-AL builds on its internal R&D, Wojnar said, adding that it is based on the company's Silent CROW podded system (pictured under the wing of a US Army MQ-1C Grey Eagle UAV).

Silent CROW was tested on a DHC-6 Twin Otter with the US Army Combat Capabilities Development Command (CCDC) C5ISR (formerly the Communications-Electronics RD&E Center, or CERDEC) in summer 2019, under a separate R&D programme.

According to Lockheed Martin, much of the capability of the system is built on an open architecture standard - the DoD's C4ISR/EW Modular Open Suite of Standards (CMOSS) - which allows for rapid cyber/EW technique development and deployment as well as the interoperability of hardware and software across airborne and ground platforms; prompt insertion of new hardware technology; and reductions in operating costs. Mesajı Paylaş
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