3D printing goes to war

From the bow to the bunker buster to the hydrogen bomb, new technologies have changed the face of warfare, and 3D printing looks set to be just as revolutionary. It's been around since the 1980s, but as key patents expire and access to the technology becomes more readily available, its effects on the military promise to be considerable – though the biggest and most immediate impact may be from a surprisingly humble quarter.

Mention 3D printing and it's likely to conjure up images of wonky key fobs brought home as trophies from middle school science projects. But the ability to print solid objects in three dimensions (also known as additive manufacturing) is more than just squirting out molten plastic under the direction of a CAD file. Modern printers can now handle metals, wood, fabric, foodstuffs, pharmaceuticals, and even living cells with not only greater precision than ever before, but also in combination with one another in complex patterns that simply cannot be matched by conventional techniques.

With the ability to work with such a range of materials, 3D printing allows engineers to create prototypes of components and even complete devices in a fraction of the time previously needed and at much lower cost. Not surprisingly, such capabilities have attracted the attention of defense contractors and military planners. The question is, how will 3D printing actually change life for the soldier of the 21st century?

Weapons of war

The most obvious area is that of weaponry. When Cody Wilson unveiled his Liberator printable plastic gun, it caused a conniption among lawmakers and gun control advocates. Keeping track of firearms so they don't fall into the wrong hands has always been a major headache on the national and international scene, but the idea that anyone with as printer and access to the internet could print a handgun stacks up as a nightmare scenario.

Worse, it soon became apparent that such printable weapons weren't restricted to plastics. Using lasers and electron beams, more advanced printing systems can fuse metal alloy powders layer by layer to form complex objects. A case in point is Solid Concepts' creation of a fully functional 1911 semiautomatic pistol from 3D printed parts. This not only looked identical to a conventional firearm, but it had all the necessary parts and could be fired.

If this wasn't enough, modern firearms are sometimes better described as weapons systems built along modular lines, allowing for a remarkable range of customization. The AR-15, for example, has been the focus of many American efforts at gun control. The AR-15 is really a vast range of parts that are fitted together as the owner desires. The only thing that they all have in common, and the only thing that can be legislated against, is the trigger assembly called a receiver – and that becomes a problem when someone starts printing them.

These examples are all of small arms, but the same problems could apply to armaments of any scale. Imagine a future where terrorists or rogue regimes could simply email one another digital files of bombs, missiles, and other weapons that could be tweaked and printed locally to make a mockery of any arms embargo. And it doesn't even need to be whole weapons. When the US Air Force retired the F-14 Tomcat, the planes didn't end up in museums or storage yards, but were fed into shredders to prevent spares from the aircraft ending up sold to Iran on the black market to keep their own pre-revolutionary F-14s flying. 3D printing would very effectively eliminate the middleman, as is illustrated by BAE Systems equipping a Tornado with 3D-printed parts.

Of course, 3D printing for the military is more than just weapons. The ability to create complex bespoke items on demand opens up a world of possibilities. We now live in a world where the armed forces not only routinely use robots, but we now have the technology to print small, fully functional robots – no assembly required.

3D printing can not only allow defense industries to create new things and old things in a new way, but also acts as a process that can greatly simplify manufacturing. When Boston Dynamics unveiled its latest Alpha robot, it not only showed a remarkable ability to walk and put up with abusive co-workers, but it was an obviously sleeker and more compact design than its predecessors. In part, this is because Alpha was built using 3D printing to incorporate many components directly into the robot's structure, similar to the way the wiring in old Bakelite phones was moulded into the plastic casing.

This is all very exciting and shows the tremendous potential of 3D printing, but it's also a bit misleading. For example, the printed guns mentioned earlier are more of a potential problem than an actual one. Plastic handguns are crude, inaccurate, unreliable, and more likely to kill the shooter than the shootee. Meanwhile, the Solid Concepts point out that the printed 1911 requires experts using state-of-the-art equipment to produce. And neither weapon is cheap. Since a competent machinist with a decent workshop could potentially crank out a workable submachine gun in an afternoon, 3D printing still has a way to go.

Boots on the ground

It can be argued that the real 3D printing revolution in the military will be more subtle, less visible to the casual observer, and much more profound than printed weapons and robots. In fact, it may be that where the revolution will really take off will be in footwear.

When it comes to the single most important piece of kit that a foot soldier has, it's probably a toss up between his rifle and his boots – with the latter having a slight edge. Ever since the days of the Roman legions, armies have been confounded by how to keep up supply of durable, inexpensive combat boots that also fit. Napoleon Bonaparte was obsessed by the problem and on his retreat from Moscow, the French troops were notorious for looting shoes from their dead comrades to replace their worn out ones.

Even today, finding a pair of boots that fit right is high on a soldier's list of priorities because badly fitting boots can literally cripple someone on the march – as I can attest from personal experience. When it comes to boots and many other bits of personal kit, many armies provide soldiers with the option of either accepting government issue or buying it personally from an outside vendor, so long at it meets military specifications. Needless to say, boots are a big ticket item.

With 3D printing, a minor miracle could be in store for the infantry. With its ability to quickly create items to exact specifications, 3D printing's first big impact could well be that every soldier could have a bespoke boot that fits every bit as well as a handmade shoe from an exclusive London cobbler.

But the implications go beyond putting a lot of army chiropodists out of business. 3D printing also implies what is known as "4D" printing. That is, the ability to create materials that change their behavior automatically based on their environment. In other words, boots that are waterproof and retain heat in a northern winter, yet breathe and remain cool in the tropics.

This 4D property is also on display in the 3D-printed uniforms that the US Army is experimenting with that could one day alter their camouflage to fit the terrain. In addition, such uniforms could fit better, have a simpler construction, and, especially in helmets, could be tailored for a particular mission and could include built-in sensors to monitor the soldier's health.

In fact, the biological aspects of 3D printing open some rather daunting possibilities – being able to heal wounds by inserting cells and knit together tissues, creating new organs to replace damaged ones, and even enhancing capabilities to alter warriors into real-life Captain Americas.

3D printing can also blend with robotics to form elegant exoskeletons that allow soldiers to carry immense loads without tiring, build prostheses that work like robotic arms, or meld human and machine to create the cyborg of science fiction.

Dinner time

Another area of 3D printing that the military is looking at is food. An army travels on its stomach, as the saying goes, and new things can affect morale more than poor rations. Keeping hundreds of thousands of soldiers fed is an incredible task, and Christmas dinner is planned months in advance with all the care of a battle campaign. Being able to print food items, such as pizzas or special diet items, at the point of order would greatly simplify things.

The 3D printed food could also be linked with embedded uniform sensors. According to the US Army, the ability to monitor each soldier's health on a continual basis could mean that individual rations could include something like a protein bar that's laced with supplements and even medications to meet individual needs on a daily basis. A six-foot soldier with a sinus infection who's on a combat patrol, for example, could be fed a bar with extra calories, nutrients, caffeine, and antibiotics. Meanwhile, a slightly-built computer programmer with mild anemia would receive a different nutrient mix with vitamin and iron supplements.

It all boils down to logistics

The military is more than just combat forces. Those are just the tip of a much larger body dedicated to getting a vast array of food, weapons, ammunition, spare parts, and thousands of other things from storerooms overlooked by paranoid quartermasters to the soldiers in the field. It's the injection of 3D printing into all of these areas that could change everything.

3D printing is already having a small impact as manufacturers experiment with printed parts, using the technique to make complex antennae, for example. These exercises have shown that 3D printing can not only make components, but actually improve on them with its ability to make very complex forms on the cheap,

As this capability matures, it could mean a revolution in logistics. Instead of moving things from factories to stores to depots, armed forces will be able to create more and more things where they are needed and the only thing that needs to be sent is a CAD file. More to the point, the ability to print items will alter how those items are designed. It's entirely possible that weapons of the future could be disposable or recyclable with much less need for spares or repair facilities.

Essentially, all this would mean that the supply line would start to short circuit. Instead of trains, lorries, cargo ships, air transports, and forward-positioned supply dumps, armies could rely on portable printing facilities and the simplest of raw or recycled materials.

In the Antarctic, a Royal Navy ship recently tested the first 3D printed drone to help navigate the ice floes. This particular drone was printed in Southampton, but the day may not be far off when the Navy will print out UAVs as required, and customize them to fit each mission. This sort of technology has already attracted the US Army, which is developing its own system of using off-the-shelf parts to create bespoke, mission-specific drones. In fact, some research has indicated that drones that can be printed in 24 hours, and some are even jet powered.

Meanwhile, the US Army is looking into the prospect of a "black box" that could be sent ahead of the troops, which would use robots and 3D printers to build a base that would be ready and waiting as the soldiers arrive. This is much more than just a "someday" thing. Space agencies are already so confident in the technology that they want to try printing bases on the Moon. At the same time UC Berkeley is playing with printable concrete, so the printable fortress or combat post may not be so far away.

The implications of such a logistical shift goes far beyond the warrior in the field. The economics of the military are based on conventional manufacturing and distribution. Contractors rely on steady orders of parts to remain in business and the prospect of armies printing their own parts, or even complete weapons, uniforms, and vehicles, could reduce many defense corporations to little more than design bureaus selling blueprints.

Certain uncertainty

What the actual impact of 3D printing on the military of the future will be remains to be seen, but one thing is certain – there will be one and it will be substantial. The examples above are only the tip of a very large iceberg and there are so many more, such as blanketing a warzone with printed sensors or tiny robots, that are yet to be explored. The impact could be as great as the introduction of the breech-loading rifle or as devastating as the discovery of iron. It will be one for the history books.

As to when this is all taking place, it's sooner than you think, because yesterday is very soon. As we said at the beginning, the technology behind 3D printing is over 30 years old. Access is increasing and the original key patents are expiring, so a gold, plastic, composite, and stainless steel rush is on. Nuclear missiles are flying with 3D printed parts, the next generation of hypersonic missiles will have them, and 3D printed medical parts are becoming increasingly common.

The revolution may not be televised, but it's already being printed.