Rethinking shoes: Two students develop 'FOOTPRINT' 3D printed custom algorithmic footwear
While 3D printed outfits and accessories have been revolutionizing fashion runways all over the world, shoe developers have been struggling a bit more with the 3D printed challenge. And that’s very unfortunate, as 3D printing could offer a solution to the ever-growing mound of non- recyclable shoes we are assembling. While 3D printing something that is comfortable, durable fashionable and perfect for our feet is surprisingly difficult, two students from Philadelphia University might have come up with a solution. For their thesis project, industrial design students Matt Flail and Tim Ganter have started the FOOTPRINT project, which aims to produce cutting edge footwear through 3D scanning, algorithmic models and 3D printing.
As Matt explained to 3ders.org, this project grew out of a frustration with all those standardized shoes out there. ‘We realized that no two feet were alike, not even our own. Why is something that is so user specific such as footwear using a standard sizing system?’ he asks. ‘Even the most advanced sneakers allow for improper fit and alignment of the body, from the ankles to the knees, hips, and back. This greatly increases the risk of injury and chronic muscle and joint fatigue.’ What’s more, modern-day shoes are woefully bad for the environment, with 300 million pairs being thrown away each year into landfills (non-recyclable) and that doesn’t even include all the waste that shoe factories produce.
It was time, they thought, to revolutionize the footwear industry. Beginning to break down the manufacturing process of a shoe, they looked at the foam compound-based shoes that main facturies produces, and talked to podiatrists about the problems shoes cause and what the optimal fit would be. ‘The biggest insight we found was that a huge issue with orthotics is trying to correctly fit them into footwear. You could have an orthotic that fits your foot perfectly and supports it correctly when laid on flat ground, but if it doesn’t fit into the sneaker correctly it can do more harm than good,’ Matt tells us.
They began looking into various modern technologies, including photogrammetry software and structured light scanning and 3D printing, technologies they discovered were woefully underused in the footwear industry. ‘We wanted to also examine how people are currently using 3D scanning to produce user specific parts. Everything from prosthetic limbs, to casts for injuries to earbuds on headphones. We also looked at how 3D printing is currently used in footwear,’ they say. ‘It is mostly used in a fashion sense, with either rigid material or semi flexible material being used to create unique looks that are more like artwork than functional footwear.’
They therefore decided to utilize these technologies as best as possible to rethink manufacturing, enable customized fits for shoes and reduce waste as much as possible. And of course, they used their own feet as test subjects. ‘These scans [of our feet] were used to create precise footbed and midsole models. These models were then taken into 3D modeling and algorithmic modeling software to create cellular structures that would in effect, mimic the cushioning provided by EVA foams commonly found in the industry. The combination of software packages allowed us to manipulate the size, shape, and position of the cells. With this technique we can essentially create variable density midsoles based on specific support needs, using only one material and one basic geometric structure (or multiples if needed),’ Matt explains. This will not only help to them to eliminate the typical health problems associated with shoes. ‘Alignment issues can finally be corrected at the source of the problem without having to produce orthotics that often don’t match up to standard sizing footwear.’
And 3D printing, meanwhile, proved to be perfect for producing low-cost customized soles, something they tested with a number of flexible filaments including NinjaFlex, SemiFlex and FilaFlex. ‘We created a number of models on traditional FDM printers (a Bukobot in this case) trying to perfect the size, shape and thickness of the voronoi cells to determine how to best provide impact protection. We were satisfied with the results of the test blocks so we began developing the midsole models and the remainder of the shoes on more advanced machines,’ Matt says.
The first subsequent tests were done using Stratasys Objet 3D printers (with TangoBlack and TangoPlus materials), but these were not suitable for footwear. Subsequent test samples produced with SLS 3D printers by Idaho-based InterMountain 3D proved more successful, using DuraForm Flex (nylon-based) material. ‘The models exhibited all of the qualities we were looking for in terms of compression and flex characteristics. The only downside is the durability of these models is questionable without being given a protective coating in postprocessing. Our intended production method at this time is SLS printing and we believe that with additional testing we can get effective models from the laser sintering process. It is very lightweight and most similar to foam,’ Matt says.
With the basic approach for the custom midsole and support section figured out, they moved on to the ‘uppers’ or the fabric portion that protects the top half of your feet and generally looks great. Having always wanted to go for knitted uppers to enable a more customized fit, they teamed up with SHIMA SEIKI, who specialize in an automated WHOLEGARMENT process. ‘Our uppers were knit in one piece with heat shrink yarn woven into them. Once knit, the uppers were placed around the foot last and steamed, which molded the heat shrink yarn around the foot for a perfect fit,’ Matt says.
And as you can see in the photos above, the parts come together as a very futuristic shoe. While originally intending to design running shoes, Matt and Tim quickly realized that this process can be applied to any type of shoe. Perfectly fitting footwear doesn’t have any boundaries after all. And with a grant from Shapeways in their pocket, they will be spending the next few months working to perfect their concepts and even test additional structures. They have also added a podiatry student to their team and his professors.
‘Working with them should allow us to identify the needs of individual patients and where we should add or subtract cells, use different materials, and create more accommodative forms,’ Matt explains. Actual comfortable, well-fitting and recyclable footwear thus seems to be just around the corner, and we will doubtlessly hear a lot more about these fantastic shoe designs in the near future.