A patent filed in 1985 is being dusted off as a source of inspiration for a new 3D-printed triangular-shaped zipper that seamlessly fastens chairs, tents, robots and purses, making them simpler to pack and set up just with a press of a button.
In 1985 William Freeman, then an electrical engineer at Polaroid but now an MIT Professor of Electrical Engineering and Computer Science, responded to an ad placed by the Innovative Design Fund in Scientific American. That ad offered support of up to $10,000 for innovative solutions for the clothing, housewares and textiles industry.
Freeman came up with the three-sided zipper, which functioned just like a regular zipper but pulled up into a triangular tube that could easily transform items like chairs, tents and purses from soft form to full size making them simpler to carry and set up.
His proposal was rejected but Freeman patented his prototype anyways, with the hope that the concept would be revisited in the future.
Building on his concept, researchers at MIT CSAIL (Computer Science and Artificial Intelligence Laboratory) have now come up with an automated and adaptable fastener called the “Y-zipper.”
“A regular zipper is great for closing up flat objects, like a jacket, but Freeman ideated something more dynamic. Using current fabrication technology, his mechanism can transform more complex items,” says MIT postdoc and CSAIL researcher Jiaji Li, lead author of an open-access paper on the project “We’ve developed a process that builds objects you can rapidly shift from flexible to rigid, and you can be confident they’ll work in the real world.”
CSAIL’s 3D software modeling program aids users in envisioning how the Y-zipper will appear when zipped up while choosing customizations such as the length of each strip, the direction and angle it curves, as well how it will appear when straight, bent, coiled or twisted before printing a 3D model using plastics.
The researchers stress-tested two types of plastic compounds commonly used in 3D printing: polylactic acid (PLA) and thermoplastic polyurethane (TPU) with a machine that bent the Y-zippers, finding that PLA handled heavier loads better, and TPU was more malleable.
The team also machine-tested the Y-zipper through a cycle of continuously opening and closing to check its endurance limit before it snapped, reaching about 18,000 cycles. 3D software modeling showed that the elastic component was key to helping disperse the stress of big loads.
When the Y-zipper is undone it resembles a three-tentacled squid, and when zipped up it forms a rod-like structure. It could have useful applications such as in camping equipment, with easy and fast pitching of a tent that normally can take “up to six minutes to do alone” but with the Y-zipper pares down to under two minutes.
The Y-zipper could be useful in the medical field. Researchers wrapped the Y-zipper around a wrist cast so the patient could adjust normally inflexible equipment to be more comfortable during daytime or night time usage depending on their needs.
Other applications might include robotics, such as adaptive robotic quadrupeds. The robot could adapt the size of its legs either by zipping for height or unzipping for lowering down, which could be beneficial for the robot to manage exploring uneven surfaces such as forest areas or canyons.
The team also built art installations with the Y-zipper, creating a long winding mechanical flower with a static motor that zipped up the installation imitating a flower in “bloom.”
Li states there are still other applications in which the Y-zipper could be beneficial, such as space exploration where a built-in arm attachment could be used to gather rock samples, or in structures that can be constructed quickly such as emergency shelters or medical tents for use during catastrophes and rescues.
Source: MIT
