ÌÇÐÄÊÓƵ

Researchers at Boise State University have developed a novel, environmentally friendly triboelectric nanogenerator (TENG) that is fully printed and capable of harvesting biomechanical and environmental energy while also functioning as a real-time motion sensor. The innovation leverages a composite of Poly (vinyl butyral-co-vinyl alcohol-co-vinyl acetate) (PVBVA) and MXene (Ti₃C₂T_x) nanosheets, offering a sustainable alternative to conventional TENGs that often rely on fluorinated polymers and complex fabrication.

TENGs are innovative energy-harvesting devices that convert mechanical energy into electricity using the triboelectric effect. They were invented by Prof. Zhong Lin Wang of the Georgia Institute of Technology and generate power through contact and motion between materials, making them ideal for applications like wearable electronics, IoT sensors, and self-powered devices.

This work, in the journal Nano Energy and led by Ph.D. student Ajay Pratap under the supervision of Prof. David Estrada of the Micron School of Materials Science and Engineering at Boise State University, showcases how additive manufacturing can produce high-performance, skin-compatible, and flexible devices for real-world applications in energy harvesting, wearables electronics, and human-machine interaction.

By integrating 5.5 mg/mL of MXene—a recently discovered class of atomically thin materials—into a printable PVBVA ink, the team achieved a remarkable 252 V open-circuit voltage, 2.8 µA short-circuit current, and a peak power density of 760 mW/m². The composite's high dielectric constant and enhanced charge transfer properties attributed to strong interfacial polarization and synergetic effect between MXene and PVBVA enabled this high performance and long-term mechanical stability, even after 10,000 bending cycles.

"This research underscores the promise of combining sustainable materials with advanced printing techniques," said Ajay Pratap. "By eliminating harmful solvents and incorporating MXene into an eco-friendly polymer matrix, we have created a scalable energy harvesting system that is not only efficient but also environmentally conscious."

The team also demonstrated a fully printed TENG device—fabricated using an ethanol-based ink and silver electrodes—which proved effective in sensing human activities such as walking, running, knee bending, and jumping. Additionally, the team demonstrated rainwater energy harvesting and real-time powering of devices like LEDs and stopwatches, highlighting the platform's versatility.

Prof. Estrada emphasized, "Ajay's work highlights how next-generation energy harvesting systems can harness biomechanical motion to generate power in real time. His innovative approach using sustainable materials and additive manufacturing paves the way for self-powered wearable devices that convert everyday human activity into useful energy."