Origami, the Japanese art of paper folding, has evolved from a primarily ceremonial and decorative practice to an important tool in science and technology. With its applications ranging from solar panels in space to self-assembling robots, origami has revolutionized the design of modern engineering solutions.

One such notable solution is a corrugated origami triboelectric nanogenerator (CO-TENG), a smart, flexible energy-harvesting sensor that combines the triboelectric effect with self-folding technology for generating power. Triboelectric generation is the process of producing electricity by converting mechanical motion—such as contact and separation between materials—into electrical energy.

Recently, a team of researchers led by Associate Professor Hiroki Shigemune from Shibaura Institute of Technology, Japan, along with Mr. Haruki Higoshi and Mr. Daichi Naritomi from Shibaura Institute of Technology, Japan, developed a CO-TENG soft sensor to eliminate the need for batteries. In this study, the team laminated copper electrodes (conductive layer) and a polytetrafluoroethylene sheet (triboelectric layer) onto paper. The self-folding solution was then printed in lines on the substrate using an inkjet printer.

By assembling the paper into a 3D structure, the researchers achieved a lightweight, low-cost, environmentally friendly, and self-powered sensor. This study was published online in the journal Advanced Materials Technologies on April 1, 2025.

“We were inspired by the structural elegance of origami and the rising need for sustainable, maintenance-free sensor solutions. So, we combined origami with the triboelectric effect to unlock a smart system that can build and power itself,” says Dr. Shigemune.

The device operates by converting mechanical stress into electrical signals through friction between laminated conductive and dielectric materials. Since the sensor also utilizes self-folding paper technology, it does not need manual folding and minimizes the fabrication effort—offering a powerful tool for next-generation smart devices.

Once developed, the mechanical properties of the self-folding paper-based structures were thoroughly studied, analyzing how the printed line width and paper thickness affected fold angles and restoring force. They first tested the parameters for a single fold and then scaled it up to a multi-fold corrugated structure to enhance output performance. Notably, serial connection of multiple origami folds led to a significant enhancement in power output with excellent durability over 1,000 compression cycles.

Furthermore, the researchers demonstrated its real-world application in a smart cushioning system. Whenever an object was dropped onto the CO-TENG, it generated electrical signals corresponding to the compression force exerted by the object. These signals were analyzed using machine learning (LightGBM), and this enabled the system to identify the objects. The system could identify the objects with a remarkable 98.9% accuracy—highlighting its potential applications in logistics and smart packaging.

“Smart cushioning could be a game-changer in logistics. 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,” explains Mr. Higoshi.

Apart from logistics, the developed nanogenerator also finds applications in the medical device and electronics industry. The high flexibility of the CO-TENG can be advantageous for wearable devices for monitoring body motion, posture, or external impacts in real-time—especially for elderly care. Its compact design makes it ideal for soft, mobile, and on-demand devices with promising applications in IoT-based personalized health monitoring platforms.

Apart from its properties, the foldable nature of CO-TENG also reduces storage and transportation costs, which are essential for industrial applications and scalability.