- Y-zipper is a 3D-printed three-sized zipper
- Is flexible when unzipped but rigid when zipped up
- The 40-year-old concept was brought to light by researchers using software and a 3D printer
Let's make zippers interesting again. Right now, they're just part of your coat, pants, or fashionable bag, but what if a zipper could serve as the framework for a cast on your broken leg, or help you construct a tent in one minute? That's the kind of zipper we could all get behind, and apparently, it exists as something called Y-zipper.
Y-zipper is the real-world realization of a 40-year-old design dream. Forty years ago, former Polaroid engineer and current MIT professor William Freedman, PhD, envisioned a three-sided zipper. It would be like a traditional zipper in that it would have pieces that interlock to form a strong bond, but by adding a third side and zipping them together, it could create a potentially rigid structure that could be unzipped to return to a flexible form.
According to a report in MIT's News Journal, though, Dr. Freeman's design was rejected in 1985 by a prestigious design competition.
In the intervening years, new materials and 3D printing arrived, making it possible to create an automated assembly and revive the Y-zipper idea.
A second chance for this innovative Y-zipper
In a project led by MIT postdoc and CSAIL researcher Jiaji Li, they created a 3D printable version of the Y-zipper. Each zipper begins as a design on the computer where Li and his team connect triangular and zippable primatives, bending and curving them however they want.
Once they have a Y-zipper's rigid design, they break it down into three printable flat zipper panels. Then they print them out, peel them off the print table, and use a custom-designed slider to weave them together. The three sections are each fed into one of three slots, and like the slider on your traditional zipper, as you pull the three pieces through this slider, they lock together and come out as a rigid shape on the other side. That shape can be a rod, a curve, or even a corkscrew (it all depends on how each side was printed and the angles contained within). When you move the pieces back through the slider or reverse the slider, the three pieces cascade apart as
It looks cool, but there are even sexier, more practical applications.
In an MIT-produced video, we see how the team designed a Y-zipper hand brace. They started on the computer with CAD software, creating a rigid shape that would curve around the hand, and, in the application, pulled it apart into three flat zipper pieces that would eventually fit together.
On the 3D-printer, they printed one flat section on a fabric glove, which, when worn, was still completely flexible. The researchers then used a small slider to zip together the two remaining sides. The resulting Y-zipper is a glove with a rigid brace. Just imagine how this could be used on, say, a full cast for a broken leg.
In another part of the video, a small robot has four Y-zipper legs that slide in and out, allowing it to walk under obstacles. Inside the robot, four sliders let the flexible portions coil back into the robot's body.
Lastly, the Y-zipper is used as the frame for a tent. The four flexible sides are sewn onto the four seams, and when the two sides are zipped onto the spines, each one becomes firm and fully supports the tent frame. And if you're particularly lazy, you can apparently attach a small actuator to the slider, and it will zip up the sections for you. In the video, this reduced the time it takes to raise the tent to one minute. Just imagine all the time you'll have to light a campfire.
The team is still working on mass-producing the materials and production, but it seems quite likely that someday we'll see Y-zippers everywhere, except maybe on your fly.
