May 1, 2013  

Print when ready, Gridley

3-D printing will streamline the Navy’s supply chain — and much more

Lt. Cmdr. Michael Llenza

Three-dimensional printing, a fast-moving technology that is still in its infancy, promises to upend the way we think about supply chains, sea basing and even maritime strategy. But it also requires us to think hard and carefully about the threats it enables and the vulnerabilities it introduces.

As Massachusetts Institute of Technology’s Neil Gershenfeld puts it, the revolutionary aspect of 3-D printing is that it allows us to make things into data and data back into things. For the Navy, the technology promises to shift inventory from the physical world to the digital one. Instead of actual parts, a ship might carry 3-D printers and bags of various powdered ingredients, and simply download the design files needed to print items as necessary.

Certainly, today’s ships and subs are not going to make everything they need on board, although it is tempting to imagine better uses for freed-up storage spaces. Today’s printers are generally limited to printing parts made of just one material, and variance is a big issue. But the development of multiple-material devices is well underway, and the technology is racing ahead. Perhaps closer at hand is a distributed global production network in which sailors and Marines send an email with a digital scan or design for a part they need and have it created at the nearest certified printer. Thinking bigger, the fleet might convert some Military Sealift Command ships into floating factories that can take print-on-demand orders from the battlegroup.

The things that might be ordered go far beyond mere parts. Several university labs and at least one defense contractor have turned out UAVs comprised entirely of printed parts, excepting the motor and electronics. A Virginia Tech lab that started printing on a Friday had by Sunday completed an aircraft that could be folded up and stored in a backpack. At the University of Southampton, researchers devised a UAV with a geodesic airframe modeled on the British Vickers bombers from World War II. The Vickers were extremely robust but incredibly expensive to manufacture — a factor all but irrelevant to 3-D printing. Finally, the University of Virginia printed a UAV controlled by a relatively cheap Android phone whose camera was used to shoot aerial imagery. Designed for a top speed of 45 mph, the aircraft crashed on its first flight. The students just went back to the lab and printed out a replacement nose cone, a capability envied by any squadron maintenance officer. The eventual goal is a drone that flies right out of the printer with electronics and motive power already in place. An organic ability to print replaceable drones from ships, forward operating bases or during disaster relief operations to serve as targets or observation platforms could be a huge enabler for sailors and Marines.

How about printed ammunition? My Army colleague at the Atlantic Council used to be the commanding officer of Radford Ammunition Plant, which produces the nitrocellulose and propellants for much of the U.S. arsenal. We started talking about printing out ammunition, and he explained that printing casings would be relatively easy, but that the idea would be a nonstarter unless you could print the energetic component as well. So we invited Virginia Tech’s 3-D printing labs to visit Radford. The Virginia Tech researchers believe the idea is worth exploring and even that 3-D printing might be able to produce propellants with geometries that provide better and more efficient burn rates. Of course, ammunition is used in such large quantities that 3-D printing may not be a practical answer for most needs. But what if you could print some ordnance to fill gaps or customize it for specific targets?

More prosaically, 3-D printing — also called additive manufacturing — offers a new way to think about building shelters or other structures on a beachhead or forward operating base. The Contour Crafting system developed at the University of Southern California features a printer head that moves on rails and draws a special cement blend from a tank or truck. It can produce a 2,500-square-foot structure in about 20 hours, ready for windows and doors. The walls printed from the cement have three times the strength of ordinary construction.

The USC group and others have also demonstrated the ability to make objects from materials drawn from the local environment. One group of researchers used a solar-powered 3-D printer to print glass objects in the Sahara Desert using the sand surrounding the machine. The USC group used NASA money and a synthetic substitute for lunar soil to demonstrate that 3-D structures could be printed on the moon. Which begs the question: What if we could harvest some of the minerals from the surrounding ocean to help create some of these parts?


Closer to home, additive manufacturing might radically change how we take care of our sailors and Marines. At Walter Reed National Military Medical Center in Bethesda, Md., the robust 3-D Medical Applications Center is already scanning soldiers’ damaged limbs so that it can print custom prosthetics, and imaging skulls to print titanium plates that fit perfectly on the first try. Such applications reflect the fact that 3-D-printing a custom version of a designed object generally requires exactly no change to the manufacturing setup.

But what about replacing skin tissue or organs? Three-dimensional printing has made its way into the field of regenerative medicine, where living cells are used instead of powdered plastics and metals. San Diego-based Organovo, the first commercial producer of bio-printing machines, has re-created lung and heart tissue, cartilage and bone. It has bio-printed living tissue with an embedded capillary system. Their process can use the patient’s own cells, eliminating the risks of transplant rejection. Today, Organovo’s main customers are pharmaceutical companies such as Pfizer, which use printed tissues to conduct “human testing” without subjecting humans to risk. Organovo wants one day to be able to print an entire organ, or at least something like it that restores a certain percentage of the disabled organ’s functionality. Which made me wonder: Why not create a specialized organ that works even better than the original?

Medical enhancement through bio-printing is one potential area of interest for the military; others include printing nonrejectable skin and bone grafts that subject the patient to much less trauma. Or on-site medical care where removal of the patient is not feasible or safe. Or testing the effects of bio-terrorism agents and irritants on lung or skin — and even developing printable drugs and vaccines. Imagine the Centers for Disease Control and Prevention emailing us the blueprints for a vaccine to avert an impending pandemic or defend against a possible biological attack.

So now that the Navy is printing parts, drones, shelters, prosthetics and perhaps some ammunition, what about the galley? “We shall escape the absurdity of growing a whole chicken in order to eat the breast or wing by growing these parts separately under a suitable medium,” said Winston Churchill in 1932. Today, a company called Modern Meadow— an offshoot of Organovo based at NASA Ames and also partially funded by the Agriculture Department and the National Science Foundation — is working on it. Its process extracts muscle cells from a cow or pig, allows them to multiply and then inserts them into cartridges to be used as bio-ink. The printer lays down the cells that develop into muscle, which can be flavored, shaped and cooked. The company’s scientific co-founder, who is also the CEO’s father, did a TEDMED conference talk in which he cooked and ate a tiny pork chop the company had created.

All of the requirements for this process exist aboard a carrier or a submarine; all you would need to add is the machinery and the “ink,” which in this case is bags of powder. Printed food, while admittedly not a terribly appealing concept, can shorten the Navy’s logistical tail, reducing security risks, costs and energy consumption.


What obstacles lie between today and the withering away of global supply lines? Let’s look at the simplest case: replacement parts. Before we stick anything in a plane or a sub, we have to make sure it’s safe. For some purposes, printed parts are fine. Boeing has 22,000 printed parts flying on various jets; Lockheed has printed parts flying on the F-35, when it’s flying.

But they’re all noncritical, nonstructural parts. Right now, there’s too much variance between parts in additive manufacturing. The quality of the printer and feedstock as well as the conditions they’re created in influence that. Standards are needed, and the National Institute of Standards and Technology held its first conference on establishing standards in November. Additionally, the Navy hasn’t bought the intellectual-property rights to any of its parts since the mid-1980s. In order to print parts for existing systems, we’d have to buy the designs, likely at great cost (though we could scan them, which would open another can of legal worms). Finally, there’s the matter of congressional mandates that specify we have to buy a certain amount of our parts from various companies. One may safely assume that Congress would have a fit once the military began consolidating plants and manufacturers in their districts because two factories can now do the work of 14.

But make no mistake, this technology will become the way we manufacture. We need only look at how corporate America is adopting it. General Electric CEO Jeffrey Immelt called 3-D printing “worth my effort, time and money,” a key statement from a company known for aggressive efficiency. It would not have bought in if it did not lower its bottom line.

In the end, an effective effort to turn the promise of 3-D printing into reality will require an overarching Navy Department strategy for additive manufacturing. Creating one will be a crucial step toward shaping the technology in order to ensure it meets the Navy’s needs and to propel it in the direction we would like it to go.


It’s not hard to imagine the dark sides of 3-D printing, and indeed, more and more media stories have been pointing them out. The biggest fear factor is the ability to democratize manufacturing — not so much what can be created, but the fact that anyone can create it. What used to require technical schooling and extensive experience can now be done with the click of a button.

The Washington Post recently wrote on its front page about Defense Distributed’s quest to produce a fully printed receiver for an assault rifle. But such stories generally leave out that such things are (so far) more easily obtainable through conventional means. Take that assault rifle receiver: The designs are readily available and the part can be easily manufactured by any shop with a computer numerical control, or CNC, machine. Similarly, many articles on printed UAVs highlight their potential malevolent uses without noting that better remote-controlled aircraft are available at your local hobby shop.

Still, the technology does raise serious questions. Once a digital design is in the ether, anyone with a printer capable of producing the part can re-create it. This has implications not just for corporate intellectual property but national security. U.S. companies and government agencies have lost control of terabytes of documents and data. What happens when the files being stolen include not just the design specifications of a top-secret weapon but the digital recipes that make it trivial to produce?

Or imagine attacks along a different vector: a hand-held computed tomography scanner peers through containers and casings, assimilates a weapon’s inner workings, and automatically generates the digital blueprints to print it.

Or take it a step further. If your enemy can steal and create files for proprietary designs, what’s to stop him from hacking into your system and modifying them? Suddenly, your printed UAVs are mysteriously collapsing upon launch. Or your bio-printed kidney fails. Or your printed vaccine, tested as safe and effective, proves otherwise. Three-dimensional printing’s emerging ability to integrate multiple materials also raises the specter of a new generation of improvised explosive devices. Imagine a fire hydrant that looks and works exactly like a fire hydrant, until a detonator touches off the explosives layered within.


Even in today’s infant state, it’s easy to see how 3-D printing might drastically enhance our naval capabilities. A capability that increases our autonomy and grants us an organic ability to produce those items that keep us operational and in the fight as long as possible will have a huge strategic impact on the service.

And more than any other service, the Navy is poised to benefit for much the same reason NASA has expressed so much interest in it. Like sailors and Marines, astronauts work in remote environments, have sharply constrained space for inventory, and are tied to long, vulnerable and at times costly supply chains. What if the Apollo 13 crew could have just printed out the part they needed?

Lt. Cmdr. Michael Llenza is the Senior Naval Fellow at the Atlantic Council’s Brent Scowcroft Center on International Security. A naval flight officer, he has completed five deployments in support of operations Iraqi Freedom and Enduring Freedom, logging more than 160 combat sorties. He has also served on the staff of the Secretary of Defense for Reserve Affairs and the Secretary of Defense for International Security Affairs.