Neural network-like microstructures induced by 2-nitrobenzoic acid in SBS fibers for high-sensitivity triboelectric sensors

Abstract

The development of high-performance self-powered flexible sensors requires triboelectric materials that synergistically integrate enhanced electron affinity, mechanical adaptability, and scalable fabrication. Herein, we present a non-destructive molecular-microstructural engineering strategy to address the intrinsic limitations of styrene–butadiene–styrene (SBS) triboelectric nanogenerator (TENG). By incorporating 2-nitrobenzoic acid (2-NBA) into a SBS matrix via an electrospinning method, we achieve dual optimization of electron-capture capability and interfacial contact efficiency. The nitro group (–NO₂) in 2-NBA significantly enhances the electron-withdrawing properties of SBS, while its inherent polarity induces self-assembled neuron-like hierarchical microstructures during fiber formation, eliminating the need for post-treatment. The resulting TENG exhibits exceptional performance at an optimal 2-NBA loading of 5 wt%, delivering an open-circuit voltage of 220 V, a short-circuit current of 412nA, and a transferred charge density of 39 nC under 10 N pressure. Notably, the device demonstrates a high sensitivity of 30 V kPa⁻¹, surpassing most reported SBS-based TENG. Crucially, this physical blending approach circumvents the safety hazards and structural degradation associated with conventional chemical modifications (e.g., fluorination) while retaining the intrinsic flexibility of SBS. The simplicity, scalability, and post-treatment-free nature of this strategy highlight its potential for industrial applications in wearable electronics, human–machine interfaces, and IoT-enabled sensing systems. This work provides a paradigm for designing next-generation self-powered sensors through synergistic molecular and microstructural tailoring.