Facile Fabrication of Hybrid Copper-Fiber Conductive Features with Enhanced Durability and Ultralow Sheet Resistance for Low-Cost High-Performance Paper-Based Electronics

The accelerating arrival of the Internet of Things (IoT) era creates a rapidly growing demand for paper-based electronics due to their low cost, light weight, flexibility, and environmental friendliness. However, manufacturing high quality circuits with ultralow sheet resistance on cellulose paper remains a challenge. Here, a method is proposed to easily fabricate hybrid copper-fiber highly conductive features on low-cost cellulose paper with strong adhesion and enhanced bending durability. A functional coating for fast surface modification of cellulose paper via an in situ cross-linking mechanism between pyridine and epoxy groups is developed to enhance copper-fiber adhesion and protect paper in alkaline electroless deposition bath. Thanks to the unique porous structure of cellulose paper, the electroless copper deposition occurs in a 3D manner in the inkjet-printed area, and forms a flexible copper-fiber hybrid structure similar to 90 mu m thick with sheet resistances as low as 0.00544 Omega sq(-1). To demonstrate its potential applications in the IoT industry, a functional battery-free circuit and a high-performance planar antenna for radio frequency identification are fabricated and tested using the proposed method.