What technology is 80 years old in theory, 40 years old in practice, and looks brand new? Believe it or not, it’s 3D printing.
Although the craze for desktop 3D printers began around 2010, when companies like MakerBot made investors and the media salivate, those in manufacturing know that the process—applying material onto a substrate to build up an object from a digital 3D design—goes back much further.
The first patent for a process called a Liquid Metal Recorder dates to the 1970s, but the idea is much older. In 1945, a prescient short story by Murray Leinster called “Things Pass By” describes the process of feeding “magnetronic plastics—the stuff they make houses and ships of nowadays—into this moving arm. It makes drawings in the air following drawings it scans with photo-cells. But plastic comes out of the end of the drawing arm and hardens as it comes.” What in Leinster’s day was science fiction soon became a reality.
Inkjet technology was invented by the Teletype Corporation in the 1960s, a method of “pulling” a drop of material from a nozzle using electronics. It resulted in a device capable of printing up to 120 characters per second and ultimately paved the way for consumer desktop printing.
Teletype later experimented with melted wax as described in a 1971 patent belonging to Johannes F. Gottwald, whose idea was to output an object made of liquified metal that solidified into a shape predetermined by the inkjet’s movement upon each new layer. This device was the Liquid Metal Recorder, which is the basis of rapid prototyping and posited that “printing” could move beyond ink.
Those were the baby steps into a territory called the material extrusion process, where thermoplastic is fed into a heated nozzle and laid upon an object one “slice” at a time in sequence—the same technique used in consumer desktop 3D printers. It’s speedy and cheap, but the materials (essentially rubbery plastic) aren’t good for much beyond model R2-D2s and racing cars.
In 1980, Dr. Hideo Kodama, a lawyer working for a public research institute in the city of Nagoya, Japan, described two methods for Gottwald’s vision using thermoset polymer—a special plastic that hardens in response to light—instead of metal. His research was published in several papers and resulted in his own November 1981 patent, but a complete lack of interest meant the project went nowhere.
Regardless, the seed was sown. Electronics and defense manufacturer Raytheon filed a patent in 1982 to use powdered metal to add layers to an object. In 1984, entrepreneur Bill Masters filed a patent for a process called Computer Automated Manufacturing Process and System, which mentioned the term 3D printing for the first time. Another 1984 patent in France described additive manufacturing using stereolithography, but like Kodama’s work, it was disregarded as having no commercial appeal.
After all these starts, inventor Chuck Hull was the first person to actually build a 3D printer. Based on his patent for curing photopolymers using radiation, particles, a chemical reaction, or lasers, his design sent the spatial data from a digital file to the extruder of a 3D printer to build up the object one layer at a time.
Hull’s company, 3D Systems Corporation, released the world’s first stereolithographic apparatus (SLA) machine, the SLA-1, in 1987. This machine made it possible to fabricate complex parts, layer by layer, in a fraction of the time it would normally take. Hull went on to file more than 60 patents around the technology, becoming the godfather of the rapid prototyping movement and inventing the STL file format that’s still in use today.
During this era, 3D printing was an emerging technology, and materials science wasn’t what it is today. If the product was made of popular polymers, they tended to warp as it set. At the time, the machines also cost hundreds of thousands of dollars, so 3D printing devices were installed only in heavy manufacturing plants—far out of the reach of consumers.
Amid widespread worries that the Y2K bug would shut down computer systems and cause digital Armageddon, 3D printing showed great potential for many industries.
During this period, bioengineering was also making important advances. Scientists at Wake Forest Institute for Regenerative Medicine in Winston-Salem, NC, printed the building blocks of a human urinary bladder using additive manufacturing and coating the organ with cells from the patient so the body was unlikely to reject the 3D-printed bladder.
The next decade saw many advances in medical 3D printing as scientists, technologists and doctors built a miniature kidney, a complex prosthetic leg, and the first bioengineered blood vessels made using donated human cells.
But the entire movement—especially the drive toward consumer use—received a big boost from the open-source paradigm sweeping the information and communications technology (ICT) sector. In 2005, Adrian Bowyer’s RepRap Project launched an open-source initiative to create a 3D printer that could build itself—or at least print most of its own parts.
The 1.0 Darwin machine was the first practical application of RepRap’s philosophy, and suddenly anyone had the power to create whatever they could dream up. Launched around the same time, Kickstarter gave home 3D printing another huge boost as crowdfunded projects sprung up everywhere. Manufacturing was democratizing fast.
Commercial 3D printing finally came to the desktop in 2006 from Objet (now Stratasys), which let users send designs to its device in order to print them from multiple materials with different properties.
Marketplaces and virtual swap meets for trading, sharing, and acquiring designs sprung up everywhere, driving a huge groundswell of interest. When MakerBot arrived in 2009 with open-source DIY kits to design and print just about anything, it made co-founder Bre Pettis into a superstar and gave 3D printing the same cachet as past emerging technologies like social media, e-commerce, and even the Web itself.
Today, additive manufacturing is a mature technology. The consumer interest and robustness of industrial platforms grew throughout the 2010s, as the (often hysterical) MakerBot hype settled down and the industry found a groove. Some think additive will replace traditional CNC and milling manufacturing in the future, and a 2021 Lux Research report predicts that 3D printing will be worth $51 billion by 2030.
The plastic desk toys have been cleared away, leaving the real-world benefits 3D printing offers: everything from printing food to applying multiple materials in the same extrusion process, making the process faster and cheaper.
The range of materials available for 3D printing has also grown exponentially, from bioprinting human tissue and the beginnings of organs tailor-made to patients to crafting products from silver or gold.
The applications are also as varied as inventors’ and engineers’ imaginations. Scientists at the University of Southampton flew the world’s first 3D-printed unmanned aircraft; the makers of a 3D-printed car reached up to 200 mpg with a hybrid gas/electric engine; and a start-up specializing in building ecological living structures came up with a robot-made habitat suitable for living on Mars.
3D printing is being used to build emergency shelter in disaster areas and affordable housing in the developing world. And smart robotics, micromanufacturing, and articulated limb design were combined to to make self-powered prosthetics that give feedback to the brain.
A lot of high-end 3D printing in manufacturing for large structures is done using powder-bed fusion, where various materials can be used in powdered form and fused together using lasers or heat. This is the main process used for metal parts, but it’s expensive and needs very particular infrastructure, making it mainly been feasible for the heavy manufacturing sector.
Nevertheless, additive manufacturing has found a home in many industries. The amount of things from your daily life with some 3D-printed component may surprise you.
Construction is a massive, entrenched field with a legacy of wasteful and dangerous practices, responsible for almost 40% of greenhouse gas emissions. But 3D printing in construction could upend the industry with cleaner methods of creating cement-based products like walls and metal components like rebar—and climate change makes these changes even more crucial.
But speed is another compelling reason to adopt 3D printing. In 2016, a Chinese company 3D printed an entire two-story house in 45 days. That same year, Apis Cor 3D printed the structure of a 400-square-foot house in only 24 hours. Additive technologies can also be deployed in precarious places like mine sites or disaster areas quickly and cheaply; research is ongoing to use materials found onsite where printers are located instead of using more fuel and smoke-belching trucks to ship in materials.
The biggest benefits of 3D printing to architecture seem obvious: designs already exist with every conceivable detail in digital form, so when you want to impress clients or investors, simply click a button and have a gorgeous model on your boardroom table just hours later. Want to change a beam, reorient a window, or add another story? Redo your drawings, rinse, and repeat.
When prototypes have to be made in or near the same factories where final production kicks into gear, it adds precious time to the design and review phase of product development if the designer and manufacturer are located far apart.
With access to 3D printing, it doesn’t matter how far-flung the factory is; a 3D printer in your office or garage can churn out as many prototypes as you need affordably and quickly, no matter how many design tweaks you have to make.
3D printing has the potential to make manufacturing viable in any region or economic climate, rather than only in the manufacturing hubs of the past 30–40 years.
A lot of manufacturing workflows already have the means to retool to additive processes. And as the product-design timeline is compressed further thanks to advances such as generative design and the easier transport and repurposing of design files, prototyping and production will happen faster, all at the speed of digital.
Early consumer 3D printing also promised to help reduce waste through a little less built-in obsolescence. If the broken part in an old vacuum cleaner isn’t in production anymore, but the design file for it still exists on the manufacturer’s website, you only have to send it to your desktop device and watch a quick YouTube video to learn how to install it.
According to Statista, the global additive manufacturing market is expected to grow 17% annually through 2023, as the applications for the technology increases and metal additive becomes more and more viable. And the market for additive manufacturing products and services is expected to almost triple between 2020 and 2026.
Industries such as manufacturing, architecture, and product design are surely reaping the benefits of 3D printing, but some of the greatest growth is expected in the electronics, aerospace, and medical industries. Todd Spurgeon, additive manufacturing project engineer for America Makes, says the electronics industry will see things like custom heat sinks for high-end products, and the aerospace industry will see a larger availability of 3D-printed components that will make their way from higher-end military applications to general aviation. In the medical industry, as more materials are evaluated for medical applications and insurance companies more broadly recognize additive manufacturing, personalized care will become the norm.
“Gone may be the days of the one-size-fits-most expensive prosthetic,” Spurgeon says. “Soon, personalized prosthetics, custom-fit to the user, are expected to be within the reach of the typical American household—even for growing children.”
Beyond the existing technologies, there is much more on the horizon for additive manufacturing. According to Spurgeon, interesting work is being done in the direct-ink-writing and dense paste material extrusion communities. For example, research groups are exploring mixing cured photopolymers with advanced material systems such as ceramics and thermosets, which can ultimately be used for things like printed circuits, lower-cost heat exchangers, and nonbulk ceramics.
“Improvements in this domain could result in a larger insertion of additive manufacturing into high-end applications such as aerospace and automotive, as well as large production processes such as the desalinization of water,” Spurgeon says. Even more opportunities surface when you consider this technology in conjunction with other additive-manufacturing modalities, such as printed circuits integrated into the structure of prosthetics or new form factors for batteries.
The list of 3D-printable materials is growing, as well. “Refractory super alloys will enable innovations in the energy, aerospace, and defence sectors,” Spurgeon says. “More durable polymers are being developed today that are likely to meet flame, smoke, and toxicity testing required by the FAA, which will result in sustainment costs reduction for relevant sectors.”
With new research and developments in additive manufacturing on the rise, the future remains bright for 3D printing—so bright that it’s time to don your new 3D-printed shades.
This article has been updated. It was originally published in September 2014. Dana Goldberg contributed to this article.
After growing up knowing he wanted to change the world, Drew Turney realized it was easier to write about other people changing it instead. He writes about technology, cinema, science, books, and more.
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