McGill University researchers have discovered a new way to fold flat sheets into smooth, curved shells that can switch from floppy and flexible to stiff and load-bearing on demand. By designing a special origami pattern and threading cable-like elements through it, they can control the material’s final three-dimensional shape and how rigid it becomes.

The result, a “doubly curved lens box,” could advance the technology of such objects as temporary emergency tents, morphing robots and smart fabrics, the researchers said. “Smooth doubly curved origami shells with reprogrammable rigidity,” by Morad Mirzajanzadeh and Damiano Pasini, was published in Nature Communications.

“Existing foldable structures face a trade-off: if they are smooth and nicely curved, they tend to be soft and floppy; if they are strong and stiff, they usually look faceted, jagged or uncomfortable, and their shape is hard to tune once built,” said Damiano Pasini, study co-author and professor of mechanical engineering.