MIT’s single-pull structures enable rapid field hospital deployment
Researchers from the Massachusetts Institute of Technology. (MIT) have developed a method for designing three-dimensional (3D) structures that transform from a flat layout into a curved, fully formed shape with a single pull of a string. The model is suitable for fast deployment scenarios, including temporary field hospitals in disaster zones where rapid medical response is critical.
The project, which received partial support from an MIT Research Support Committee Award, starts with a user defined 3D design. An algorithm converts this shape into a flat arrangement of interconnected tiles. These tiles are linked by rotating hinges and actuated through one continuous string. A two-step optimization process determines how the string should be routed so that friction is kept to a minimum, allowing the structure to rise smoothly into its intended form.
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Once deployed, the mechanism can be reversed by releasing the string, causing the structure to return to its flat configuration. This makes storage and transport more efficient while reducing cost. The method is also independent of manufacturing technique, allowing the same designs to be produced through 3D printing, CNC milling, molding, or related processes.
The work opens possibilities for transportable medical equipment, foldable robots that can pass through confined spaces, and modular habitats that could be assembled by robots on planetary surfaces. According to lead author Akib Zaman, an EECS graduate student at MIT, the benefit lies in the simplicity of the actuation. Users only need to submit their design, while the system prepares it so the final structure holds its shape after one pull of the string.
The research team includes MIT graduate student Jacqueline Aslarus, postdoctoral researcher Jiaji Li, Associate Professor Stefanie Mueller of the Human Computer Interaction Engineering Group in CSAIL, and senior author Mina Konaković Luković, assistant professor and head of the Algorithmic Design Group in CSAIL.
The technique draws inspiration from kirigami, the Japanese art of paper cutting. The algorithm breaks a design into a grid of quadrilateral tiles that behave as an auxetic system, meaning the structure thickens when stretched and thins when compressed. This behavior allows flat patterns to encode complex 3D geometry.
After the tile layout is created, the algorithm determines the minimum set of lift points needed for deployment. It then computes the shortest string path that connects these points while passing through key boundary areas. An established physics equation is used to model friction along this path, ensuring reliable actuation.
The researchers tested the system across multiple scales. Demonstrations include personalized medical items such as splints and posture correctors, a portable igloo-like shelter, and a full-scale deployable chair. Because the method does not depend on size, it could also support miniature devices intended for use inside the human body or large architectural frameworks assembled on site.
The team hints at refining designs for very small structures and examine engineering limits for architectural applications, including hinge strength and cable dimensions. They are also exploring ways to make the structures self-deploying without human or robotic input.
Category: Education
