Researchers Turn to Origami to Build a Self-Folding, Energy-Harvesting Smart Cushion Sensor

Researchers from the Shibaura Institute of Technology in Japan have borrowed from origami, the art of paper-folding, to build a self-powered sensor designed for smart wearable devices — by adding sensing capabilities to a corrugated origami triboelectric nanogenerator, or CO-TENG.

"We were inspired by the structural elegance of origami and the rising need for sustainable, maintenance-free sensor solutions," explains project lead Hiroki Shigemune of the team's work. "So, we combined origami with the triboelectric effect to unlock a smart system that can build and power itself."

The triboelectric effect sees mechanical motion converted into electrical energy. In this case, it's the motion of a folded sheet of paper functionalized with the addition of a layer of copper electronics and a polytetrafluoroethylene sheet laminated into place. A solution printed from an inject printer causes the sheet to fold itself origami-like — and as it is opened and closed the mechanical stresses caused by friction between the layers is converted into electrical energy.

To prove the device's capability as a sensor, rather than a simple energy harvester, the team created a "smart cushion": whenever an object was dropped onto its surface, the CO-TENG devices generated electrical signals corresponding to the overall compression force — which could then be fed to a machine learning model to distinguish between different sizes and weights of ball with a 98.9 per cent success rate.

"Smart cushioning could be a game-changer in logistics," Higoshi claims of the real-world applications of such a sensor. "By using the CO-TENG system, dropped objects can be automatically identified and monitored in real-time, offering new capabilities in shipment tracking and product integrity verification."

The team's work has been published in the journal Advanced Materials Technologies under open-access terms.