An applied maths professor and her team have dreamed up inflatable origami structures they say could save time and energy in erecting emergency shelters, such as those vital to refugee camps.
Taking inspiration from the ancient Japanese paper-folding art, the team have designed and produced a structure that expands from a flat structure into a 3D construction and locks into place when pumped full of fluid, most likely air, according to a paper in Nature this week.
Katia Bertoldi, professor of applied mechanics at Harvard University, and her team showed a tent-like shelter of 2.5m × 2.6m × 2.6m in size can be produced from a folded form of 1.0m × 2.0m × 0.25m and be held in shape automatically with internal hinges without the need for continuous inflation. Applying a vacuum can then collapse the structure when necessary (watch the video for a demonstration).
In an accompanying article, Princeton University Department of Civil and Environmental Engineering associate professor Sigrid Adriaenssens said of the research that the innovation could "save storage space, transportation costs and setting-up times, and the self-locking inflation system would enable easy and robust deployment."
She explained that while scissor lifts and bouncy castles offer examples of deployable structures, they either need solid structures as a foundation or constant inflation.
The researchers' innovative approach was to design enclosed origami shapes that have two or more stable equilibrium states by connecting the rigid facets with stretchable hinges. "These hinges deform to resolve the geometric incompatibility, and thus allow the system to shift from one local minimum-energy state to another," Adriaenssens said.
But she pointed out scaling might be an issue when the mass of the structure itself becomes significant, into the realm of 10 metres to 100 metres in size.
So, although useful for temporary or emergency shelters, the approach may have its limits on this planet – although not off it.
"Several issues will need to be addressed before the structures can be used at large scales on Earth. But having the ability to transport large objects in compact forms is also highly desirable for space missions. Moreover, the reduction of gravitational force — and the absence of building regulations — in space would also facilitate the use of the new origami technology," Adriaenssens opined. ®