Square-Structured Nylon/Chitosan Oligosaccharide-Based Triboelectric Nanogenerator for Omnidirectional Low-Frequency Energy Harvesting

Owing to their capability of converting low-frequency mechanical motion into electrical energy, triboelectric nanogenerators (TENGs) have become an attractive solution for powering next-generation wearable electronics. Nevertheless, the relatively limited output performance of wearable TENGs still constrains their application in a practical self-powered scene. Herein, we develop a high-performance square-structured TENG (SS-TENG) based on a nylon/chitosan oligosaccharide (COS) composite electrospinning mat (NCEM). Benefiting from the strong polarity of COS, the NCEM exhibits enhanced positive triboelectric properties, leading to a significant boost of about 10-fold higher output compared to pure nylon. The optimized NCEM achieves a maximum improvement to TENG's power density (4.6 W/m²), surpassing most reported biobased triboelectric materials. Furthermore, the SS-TENG demonstrates excellent omnidirectional biomechanical energy-harvesting capability, effectively capturing mechanical inputs from various directions during human motion. It also demonstrated excellent omnidirectional energy-harvesting capability in swing tests ranging from 15° to 45° and from 0.67 to 2 Hz while also featuring good durability and output stability. When suspended on a backpack, the device robustly converts complex, real-world biomechanical motions into usable electrical power to drive small wearable electronics. This work offers an efficient and environmentally sustainable strategy for improving triboelectric performance and facilitating innovation in a next-generation wearable system.