MIT engineers have developed a flexible, shape-sensing sheet that digitally reconstructs its own form as it bends and twists. The sensor is similar in principle to some motion-capture garments, which track a person’s physical movements to mimic them in a virtual avatar. Those designs use rigid sensors that are stitched into a suit at strategic locations.

In contrast, the team’s new design uses multiple soft optical fibers that zigzag throughout a soft and stretchable sheet. When the sheet bends, the fibers bend in kind, changing the pattern of light that travels through them. The researchers developed an algorithm to interpret the bending light patterns on the fly to create a digital image that moves the same way the sheet is moving. The team also showed that the design is resistant to damage: Even when a few fibers are cut or disconnected, the remaining fibers can still accurately reconstruct the sheet’s overall shape.

“Our setup is targeting fully soft and stretchable sensing surfaces so it’s potentially safer for interacting with a human or a soft environment,” says Qifan Yu, a mechanical engineering graduate student at MIT.