In 1985, electrical engineer Bill Freeman conceived a three-sided zipper capable of transforming flexible objects into rigid structures. Rejected by a design competition, Freeman patented the idea and stored the prototype, where it remained for nearly 40 years.

Researchers at MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL), led by Jiaji Li, have now brought Freeman's concept to life as the Y-Zipper. This 3D-printed fastener can convert floppy structures into load-bearing beams with a single pull. The CSAIL team developed an automated system allowing users to customize strip length, bend angle, and motion configurations before 3D printing.

The Y-Zipper's ability to reversibly switch between soft and rigid states addresses limitations of previous "tunable stiffness" attempts. Potential applications span camping gear, medical equipment, robotic limbs, and art installations, with future possibilities including spacecraft and disaster relief structures. The innovation challenges the notion of fixed material properties, offering a new paradigm for building adaptable objects.