adidas 4D completely rethinks how a sneaker's sole is made. The revolutionary design uses a form of 3D printing known as Digital Light Synthesis to create a cushioned, responsive, and light sole unit. Although, in theory, the process of making a 4D sole is no more complex than more common sole manufacturing technologies such as injection molding, the process is still somehow hard to get your head around.
The technology itself was created in partnership with California-based firm CARBON and first appeared over two years ago. Originally launched in very limited quantities, in the last eighteen months the tech has become more widely available thanks, in large part, to the AlphaEdge 4D and the ZX 4000 4D.
Last week, in its recently opened, high-tech London flagship, the three stripes hosted an event celebrating the future of sport. As one of the brand's most innovative technologies, 4D will play a central role in that future, which was highlighted at the event through a dedicated 4D zone at the entrance of the store and talks given by adidas running creative director Sam Handy. Prior to his presentation, we sat down with Handy to get a deeper insight into the technology and how it differs from Boost as well as details on the brand's recycled Loop sneaker.
Can you explain 4D technology in its most simple terms? A fusion of liquid oxygen and light, a robot arm with a projector that pulls a solid out of a liquid. The light hardens the liquid as it pulls vertically through to the surface. Imagine a CT scan or an X-Ray, where you move in and out of layers, that's literally how it works. It prints layer upon layer.
How long does that take? Each midsole takes about 15 minutes.
How did adidas connect with Carbon? The project came around when our board member, Eric Liedtke, was spending a lot of time in Silicon Valley and he encountered this company that was taking a really interesting approach to 3D printing. We'd built 3D printing prototypes before but we didn't know how to bring them to mass production, so the Carbon technology let us do that.
Are you working on any other projects together? So I'm working on Spring 2021, Fall 2021 and Spring 2022, there are lots more shoes coming and some really interesting stuff. We're taking the technology and innovation further and further. So more performance, better functionality, more comfort.
In the future will you explore more than just soles? Yes. More than just soles and more soles. I think one of the biggest things with 4D is that we want to give it to more and more people. We're now the world's biggest 3D printer based on that one model.
What are the most important 4D models? Currently, the AlphaEdge 4D is the flagship performance shoe and there's also a shoe from Originals, the ZX 4000 4D.
What were the main goals for 4D from a performance point of view? To equal the performance of Boost in a completely tuned midsole. But now we're taking it much further than that because you can tune it so precisely, you can put function where you really need it. You could completely program it so you can make it softer here, harder here, more propulsive here. With Carbon 4D you can engineer cushioning, spring energy, return and propulsion all into one sole. That's what's really exciting about it from a performance perspective. You can tune every aspect.
Is there a plan to eventually make bespoke soles for each runner? That's the North Star. The ultimate goal is to have personalized soles, but we're not quite there yet. The machines are just taller than me, so easier to handle and have in stores than say a Boost machine, which is the size of a house.
Does this signify a move away from Boost? 4D is an alternative that delivers a tuned experience. Boost is for the best energy return. We continue to invest in Ultraboost – the Ultraboost20 is launching in a few weeks. We really believe in Boost but 4D is about tune-ability.
The sole has become a street-level signifier of “cool sneakers,” what is your reaction to this? It’s funny, I’ve worked in Originals, Football and in Running. For me, the most enduring sneakers ever started as high-performance shoes. It’s about credibility and a true purpose. I like to believe that it matters if you can really perform in a shoe. I think that's the difference between a fashion brand making sneakers and a sports brand. They work based off insights, the products are made by a team of engineers and scientists and designers. I think they're beautiful because of their functionality. They don't exist to look cool, they exist to work.
It is made from plastic, but how does that fit in with adidas' overall sustainability goals? You can look at plastic in a couple of different ways. Plastic is a design failure because once it's made it stays there. So it's about how you use it. With 4D, whilst it is a plastic, the 3D manufacturing process means you only make and use what you need, there's no trimmings or excess. And when you look at what we're doing with the Loop shoe, for example, this is a common plastic product but it takes one chemical only to form the entire shoe. That means the entire shoe can be recycled. What we're doing with Loop is an indication of where we take plastics in general. We're not removing plastics, we're using plastics in a way that's sustainable.
What's the story behind the Loop shoe? The inspiration for the Loop shoe is based on our understanding that plastic is a big problem. It's a very radical product because it's built out of one material. With a normal piece of footwear or electronics, you can recycle each individual material, the problem is that they're all bonded together. We launched 200 of the Loop to beta testers in April this year and they’ve all given them back to us, although no one wanted to. We ground them down and used them to create the second generation of Loop. We will then take generation two back to make generation three. It's about changing the mindset of how we use footwear.
What's holding you back from scaling production? Learning how to really do it and some costs. So again, this is the edge of material science, so it's quite expensive to build, but every time we make another pair we learn how to reduce the cost, how to make more, and how to do it better and more efficiently. I've got three kids. Thinking about the amount of footwear we generate. What do you do with it? The idea that you just give it back to adidas and they reuse it in their supply chain is amazing.
Learn more about 4D, here.