Month: November 2017

It’s been just a few months since Lockheed Martin gave the US Army the most powerful laser weapon ever developed, a ground vehicle–mounted system that can burn through tanks and knock mortars out of the sky. Now the US Air Force wants its own toy, so Lockheed’s engineers are back in the lab, crafting the kind of weapon Poe Dameron could get down with. They’re making a laser blaster for a fighter jet to swat down incoming missiles.

Decades after science fiction writers and directors imagined worlds of killer beams flying back and forth, reality is catching up. This spring defense contractor Raytheon became the first to destroy a target with a laser fired from a helicopter. At White Sands Missile Range in New Mexico, the Apache AH-64 shot a truck from more than a mile away, while on the move and from a variety of altitudes. Raytheon is also building a laser-firing, drone-killing dune buggy. Boeing has its own anti-drone laser cannon.

“This technology has been described as ‘coming’ for so long—with it never actually arriving—that people took to believing that it would never happen,” says military analyst Peter Singer. “Well, now it’s happening. After so many false starts, we’re seeing real breakthroughs that are starting to make the idea viable.”

The key enabler has been the development of solid-state lasers, which run on electricity. The previous frontrunner tech was the chemical laser, which requires large amounts of chemicals to generate the reaction that produces its powerful beam. In 2012 the US Missile Defense Agency shelved its Airborne Laser Test Bed, a Boeing 747-based chemical laser designed to shoot down ICBMs, because it was too costly and unwieldy.

In the past decade, solid-state lasers have grown in power and efficiency, to the point that they now represent a viable alternative, one with its own advantages. “We’re now able to generate a focused, powerful beam and are able to hold it on the target long enough to disable it,” Raytheon CEO Tom Kennedy says. “It represents a limitless magazine, as long as you have electricity.”

Now it’s up to Lockheed to bring the pew to the air. The new assignment falls under the Air Force Research Lab’s Self-Protect High Energy Laser Demonstrator program, which, in the ever flexible world of military acronyms, is also known as Shield. The defense contractor is aiming to have a system it can test on a fighter jet by 2021.

Lockheed will be adapting the system it developed for the Army to address the challenge presented by this new $26 million contract, with a goal of self-protection against ground-to-air and air-to-air missiles. The program’s work will be divided among three subsystems, each with its own strained acronym. The Shield Turret Research in Aero Effects (Strafe) includes the beam control system. The Laser Pod Research and Development (LPRD) will power and cool the laser on the fighter jet. Then there’s the laser itself, known as the Laser Advancements for Next-Generation Compact Environments (Lance). The core technology will be a fiber laser, which uses fiber optics to enhance the power of the beam, with multiple individual lasers bundled together to create a scalable system.

Despite recent advances, making a laser weapon work on the highest-speed military vehicle poses a significant challenge. “We’re putting a weapon traveling at the speed of light onto an aircraft capable of traveling the speed of sound, while targeting threats likely also traveling at supersonic speeds,” says Rob Afzal, Lockheed’s senior fellow for laser weapon systems. And it has to work on the move, no matter the turbulence or weather conditions. “Ruggedization is critical.”

Then there’s the question of reducing the laser’s size, weight, and power consumption to the point where it can work on a small jet. Lockheed developed the aforementioned Airborne Laser Test Bed for the Missile Defense Agency, but that system took up most of the 747’s fuselage. Using a solid-state system should help there. “Not only have we reduced size, weight, and power enough to move from a large plane to a tactical fighter jet, we’ve also reduced the laser to be part of a pod,” Afzal says. “This is a technology maturity level that just five years ago we would have said may take a long time to develop.”

If Lockheed can deliver, the Air Force gets a weapon that’s not just lighter and (likely) cheaper than equivalent missile and machine gun systems, but one that could change how it deploys its fighters. If you’re packing a missile-killing laser, you can go places and do things that now demand the sort of extremely expensive stealth tech of the F-22 Raptor and the F-35 Lightning. “The ability of a helicopter or bomber or fighter jet to shoot down or sufficiently damage or distract an incoming missile could allow them to operate in places they haven’t been able to operate recently,” says Singer, the military analyst. “This will allow non-stealthy planes that previously couldn’t defend themselves new potential lives in future combat scenarios.”

Even if that doesn’t eliminate the need for stealth aircraft—since those systems are largely undetectable and offer the element of surprise—Singer argues that they can work as force multipliers. Better yet, they can provide insurance against the quantum radar systems reportedly being developed by the Chinese, which can spot even the stealthiest aircraft. Being invisible isn’t so crucial when you’ve got a laser that lets you waltz into enemy territory, do your job while zapping missiles out of the sky, and cruise home.

At least, that is, until the enemy develops lasers of its own. Then, it’s on to whatever sci-fi weapon comes next. Death Star, anyone?

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Army of One Day

Using a commercial printer and some silver ink, researchers from Florida State University have found a novel way of producing motion sensors en masse. The low-profile sensors support new applications in wearable electronics, structural health monitoring, and, perhaps soon enough, microrobotics.

Lead researcher and doctoral candidate Joshua DeGraff assembled the technology from buckypaper — razor-thin, flexible sheets of durable carbon nanotubes.

In addition to a strip of seven micron-thin buckypaper, the sensor features silver ink electrodes printed from a common, commercially available EPSON Stylus C88+ ink-jet printer.

Degraff, along with Richard Liang, professor and director of Florida State’s High-Performance Materials Institute, spoke with Tech Briefs about how the manufacturing method offers an important benefit for emerging technologies like wearables and robotics: scalability.

Tech Briefs: What are the characteristics of buckypaper?

Dr. Richard Liang: Buckypaper is a carbon-molecule thin film, about 10-15 microns in width. All the carbon nanotubes work in tandem together. The material is extremely lightweight: 5 grams per square meter. By adjusting the contact between the carbon nanotubes, you achieve a wider range of conductivity and sensitivity.

Tech Briefs: How is the buckypaper sensor made?

Joshua DeGraff: We use the printer and silver ink to print patterned electrodes on low-profile plastic substrates. Then, we position our buckypaper films on the printed circuit and laminate it. Lamination holds everything in place and protects the components. We then crimp on low-profile electrical contacts for easy connection. I’m able to print out maybe 100 sensors at a time, and I can make them pretty fast.

Tech Briefs: What is the sensing element?

DeGraff: The buckypaper is the sensing element. It’s very sensitive — about eight times more sensitive than commercial sensors that are usually just made out of metallic prints. Its function is to provide the change in resistance and conductivity. The whole point of this is to have a low-profile sensor that’s scalable, so we can print these in large quantities in continuous fashion.

Dr. Liang: If you want a wearable sensor for everybody, scalability and affordability is key. If somebody wants to cover the whole human body with sensors, we can do it in a very affordable way. We don’t need a very expensive 3D printing machine. We don’t need to use very special conducting ink. You can make 100 sensors a day; that’s a very unique scalability.

Tech Briefs: What applications do you envision right away? What applications do you envision in the future?

DeGraff: Right away, I see the sensors in wearable technology. We were able to integrate our sensors into gloves. The sensors detect very small finger movements, and also large bending movements.

I also see the sensors in structural health monitoring soon. The sensors can basically detect “invisible” deformations and microstrains that we can’t see with the naked eye. They’re affordable, and we can use them to create sensor arrays. We’re doing more lifecycle tests, especially with structural health monitoring with carbon-fiber composites. Down the road, when we figure out how to integrate the sensor with the artificial muscles, we may see them in microrobotics and soft robotic systems.

Tech Briefs: Has buckypaper been used before as a sensor material? Is this a novel approach?

DeGraff: They’ve been used in other sensors, but the problem is the way they are commercialized and manufactured. You want it to be a scalable process. You also want to have the mechanical properties, so you can have a highly sensitive sensor. We have a mixture of both here, and that’s why we have such a high gauge factor [how much resistance value changes as a material is strained or bent]. We can print out lots of sensors at a time, and we can even tailor them to different applications.

Tech Briefs: What’s most exciting to you about this sensor?

DeGraff: I like the fact that it has a wider range of applications, and we can help people out in their daily lives, and not in just one sector, like aerospace. When it comes to wearable technology, athletes can track how intense their workouts are.

You can count your steps. You can have bed sheets that can tell, by your movements, how well you’re sleeping. You can help people who have carpal tunnel syndrome, who are going through treatment, and who need to know how well their self-rehabilitation is going. It can go from there to the structural health monitoring and the detecting of vibrations in buildings.

Tech Briefs: Do you have any advice for fellow engineers and sensor researchers?

DeGraff: If you have an idea and you have the materials, just try it. Instead of wondering whether or not it will work out, or reading if somebody else did it before, take the initiative; try things out yourself and see how it works out for you.

What do you think? Will scalable motion sensors improve adoption of wearables? Share your thoughts below.

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