Engineering: Inflatable origami structures stand up to pressure

An origami-inspired approach to produce inflatable structures, such as arches or shelters, that lock into place after deployment is described in Nature this week. The research may pave the way to using large origami structures for engineering.

Structures that are compact enough for transportation but can transform into large configurations can have multiple applications, from bouncy castles to scissor lifts. Designs that can be deployed with relative autonomy and do not require further input once expanded are highly desirable. Taking inspiration from the Japanese art of paper folding, Katia Bertoldi and colleagues make origami shapes that can be inflated into self-supporting expanded structures.

The authors identify the geometric parameters required for the construction of inflatable structures, including the requirement for multiple integrated triangles (for rigidity) and flexible hinges. Structures can be inflated and lock into place once deployed, without the need for continued inflation, but can be returned to a compact conformation using a vacuum pump. The authors show that an inflatable arch 60 cm tall and 150 cm wide can be inflated from a folded configuration that is 20 cm tall and 30 cm wide. In addition, a tent-like shelter with an expanded shape that is 2.5 m × 2.6 m × 2.6 m in size can be folded to occupy a space of 1.0 m × 2.0 m × 0.25 m.

The origami structures reported here could “save storage space, transportation costs and setting-up times, and the self-locking inflation system would enable easy and robust deployment”, writes Sigrid Adriaenssens in an accompanying News & Views article. However, she notes that several issues will need to be addressed before the structures can be built at large scales, as larger objects may be more susceptible to compressive and tensile stress variations and deformations.

After the embargo ends, the full paper will be available at: https://www.nature.com/articles/s41586-021-03407-4