Scalable Self-Powered Sensor Based on Triboelectric Nanogenerators with Surface-Modulated Electronegativity for Harsh...

The growing need for self-powered sensors in extreme environments, such as biomedical implants, industrial monitoring, and deep-sea exploration, has driven interest in triboelectric nanogenerators (TENGs) as efficient energy harvesters. However, the challenge lies in developing a scalable, cost-effective fabrication process that maintains stable performance in water and across a range of varying temperatures. This study presents a surface modification strategy that enables precise modulation of electronegativity through a scalable and straightforward immersion process. Unlike conventional methods that rely on nanostructuring to enhance triboelectric activity, our approach utilizes surface functionalization to chemically anchor elements with varying electronegativities onto the substrate. These strong chemical bonds effectively modify the substrate's electronegativity, thereby enhancing the TENG's electrical output on both sides. The process is scalable beyond A4 size, making it well-suited for roll-to-roll manufacturing. By functionalizing polydimethylsiloxane (PDMS) electrodes with fluorine (-F) and amino (-NH₂) groups, we significantly increase the triboelectric potential difference, enhancing charge transfer efficiency. Experimental results demonstrate that the NH₂/fluorinert-modified TENG achieves an output voltage of 2.25 V and a current of 40 nA─an output current 600 times greater than that of pristine PDMS/PDMS. Additionally, theoretical simulations confirm a 225-fold increase in triboelectric potential, demonstrating the fundamental impact of electronegativity modulation. The device exhibits stable performance across a temperature range of 25-100 °C, in underwater conditions, following surface functionalization after thermal annealing, and under prolonged mechanical stress. This work represents a major breakthrough in scalable TENG fabrication, bridging laboratory innovation with commercial application. The demonstrated large-area fabrication approach unlocks new possibilities for wearable electronics, industrial sensing, and energy-efficient IoT devices, making self-powered technology more practical and accessible.