Fiber‐Based Flexible Ionic Diode with High Robustness and Rectifying Performance: Toward Electronic Textile Circuits

Abstract In response to the growing demand for wearable devices designed for seamless integration with 3D bio‐surfaces, fiber‐based devices have gained prominence in textile‐based wearable electronics due to their flexibility and unique structure. In particular, though diodes with rectifying properties are crucial for a range of electronic systems, there has been scant reporting on diodes with a fiber structure. This study introduces a fiber‐based flexible ionic diode that exhibits a rectification ratio of 2773 and an output current of 28.2 mA at 3 V. The diode is composed of a double helical Zn‐based fiber anode, a Ti‐based fiber cathode on Au nanoparticle‐based flexible fiber electrodes, and a LiCl hydrogel electrolyte. By modulating the double helical design and the ionic conductivity of the hydrogel, the electrical performance of the diode to achieve varying rectification ratios and output currents can be tailored. Owing to the remarkable flexibility and stability of the fiber electrodes, the fiber‐based ionic diode consistently upholds its rectifying capabilities, even under washing procedures and significant bending deformation. Furthermore, this diode seamlessly integrates into various electronic circuits, including half‐wave rectifiers, capacitor–diode filters, and logic gate systems.