The footwear industry has been teasing us for years about 3D-printed athletic shoes for the masses. Why? Everyone’s feet are different, our strides vary, but shoes are basically the same. Someone who’s 250 pounds and a size nine will need different support than someone who’s 150 pounds and wears the same size. Mass customization enabled by 3D printing could give everyday consumers the performance-boosting kicks that are currently relegated to the domain of elite, professional athletes.
Today, Adidas announced Futurecraft 4D, the company’s first mass-produced, 3D printed shoe. By the end of the year, Adidas plans to produce at least 5,000 Futurecraft 4D shoes and even more after that; price has yet to be determined.
“This is the holy grail,” Eric Liedtke, an Adidas executive, said at the sneaker’s unveiling Thursday night.
Futurecraft 4D looks just like Adidas’s popular Ultra Boost sneakers and has a seamless black mesh upper and thin rubber treads. But what makes it different is its midsole: It’s a flexible, 3D-printed polyurethane elastomer whose lattice structure varies in density to give a wearer’s foot support and cushioning where it’s needed. (The midsole is single-density foam in regular Ultra Boosts.)
Futurecraft 4D was developed by Carbon, a 3D printing company based in Silicon Valley, and Futurecraft, Adidas’s innovation arm, which typically focuses on moonshot projects, like shoes made from ocean plastic and shoes that can biodegrade in your sink.
While the brand unveiled limited-edition 3D-printed shoes last year, it didn’t have the manufacturing infrastructure to bring them mainstream. (UnderArmor also launched a 3D-printed shoe last year, but only made 96 pairs.) The available 3D-printing technology wasn’t able to produce midsoles fast enough, with the right physical properties, or at scale. In other words, the 3D printers were still prototyping tools, not a means of production.
Joseph DeSimone, Carbon’s CEO and co-founder, was always thinking about footwear applications when he was developing his company and its technology. “Everyone who was doing 3D printing in footwear was frustrated,” he tells Co.Design. “It was slow, it was unscalable–we knew it was only prototyping.”
Carbon’s technology is called Continuous Liquid Interface Production (CLIP), a proprietary adaptation of stereolithography (SLA), a process by which forms “grow” from resin. The 3D printing technique that we’re most accustomed to seeing—like what at-home desktop printers use—is known as additive manufacturing. A stylus squeezes out a substrate and builds up layers of the material until the form is complete. SLA, on the other hand, uses an ultra-violet laser to transform light-sensitive liquid into a solid. As the light creates the form, the printer pulls the solidified material up, exposing it to oxygen, which stops the chemistry. This is repeated over and over until the form is complete. It would take hours for this process to create one of Adidas’s Futurecraft 4D midsoles.
CLIP, like SLA, uses light to turn the resin into a solid, but unlike SLA it incorporates oxygen into the process in a continual cycle. A very thin layer of resin–just a few millimeters thick–is spread over an oxygen-permeable glass membrane. As the light solidifies the membrane, oxygen creates a microscopic zone–about 1/3 the thickness of a human hair– where the resin can’t solidify. Without that “dead zone,” as Carbon describes it, the resin would adhere to the glass, and they’d have to stop the 3D printing process and add more resin. There’s no need to stop Carbon’s process, which was patented in 2014, to produce one of the Futurecraft 4D soles.
“It’s all about speed, quality, and materials,” DeSimone says. “Traditional printing takes tens of hours to do; we’re now doing it in tens of minutes. That’s the key.”
“[3D printing] isn’t a toy anymore, it’s not a concept,” Liedetke tells Co.Design. “Every other thing you’ve seen from 3D printing in our industry has been a functional prototype because it’s limited by the process. But what this does is takes the limitations off. We started [this project] a year ago. Now we’ve produced [300 pairs]. In a few months, we’ll have 5,000 pairs in the market, and a few months after that we’ll have 100,000 pairs in the market. Why would I not say millions in the future?”
Adidas and Carbon have the manufacturing technology to bring 3D printed shoes mainstream. But there’s still some ambiguity here. DeSimone and Liedtke weren’t able to give specifics about where they’re producing the shoes or their production schedule, like how many printers and what type of output they’d need to get the 5,000 pairs by Q4 of 2017. Liedetke did say that they plan to install Carbon’s 3D printers at the Brooklyn Farm, Adidas’s new creative studio in Brooklyn, and at Speedfactory, its new Atlanta production facility.
Additionally, for the full potential of customizable 3D-printed shoes to become mainstream, Adidas would have to come up with a retail experience that would measure a customer’s foot, gait, and other key data points. The “4” in “4D” stands for data. To come up with the actual design of the midsole–like the density of the lattice, the contours, etc.–Adidas used running data captured from thousands of athletes. The company isn’t able to collect this type of information from individuals and incorporate that into a custom shoe, but by shoring up the manufacturing and scaling ability, it’s one step closer.