Ag/GNS conductive laminated woven fabrics for EMI shielding applications

ABSTRACT

In flexible electronics, a highly electroconductive, flexible, and durable material is important for various applications. This study describes the property changes in graphene nanosheets (GNSs) doped into a conductive silver (Ag) paste that is used to form a grid-style pattern on a polyurethane hot melt film (PU HMF) for electromagnetic wave shielding. Electrical conductivity, thermal conductivity, and bending tests were performed for materials fabricated by an electronic printing method. The results showed that the conductive paste with a loading of 0.3 wt% GNSs (3SC) had good electromagnetic shielding effectiveness (EMSE, 49.9 dB at 1800 MHz), much better electrical conductivity (4.63*10⁴ S/cm) than the pure silver paste (1.38*10⁴ S/cm), and an improved bending ability. The coefficient of variation of GNS loading (3.01% to 3.80%) under 1000 cyclic bending tests was better than that of the pure silver paste (6.94%) at 2.4% strain, but the results under 500 cyclic elongation tests at 10.0% strain did not exhibit the same pattern. The coefficients of variation (CVs) of all samples in the GNS group (8.3–13.3%) were worse than those of the pure silver group (6.3%) after the elongation test. The reason for the differences in the electrical conductivity and flexibility was explained by the SEM results, which indicated notable damage after the bending and elongation tests. Woven fabrics laminated with a PU/Ag/GNS conductive film that were doped with different amounts of fillers were successfully manufactured by electronic printing and can be used for Electromagnetic Interference (EMI) shielding materials, electrodes for sensor components, wearable elements, smart home textiles, and conductive materials, for example.

KEYWORDS:

• Conductivity
• EMSE
• fabrics
• graphene
• laminated
• screen printing
• silver

Acknowledgments

The authors also thank the Institute of Polymer Science and Engineering, National Taiwan University, Taiwan, for guidance on materials and formulation principles and the Fiber Structure Lab of Feng Chia University, Taiwan, for providing all necessary instruments.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This research was funded by the Ministry of Science and Technology (MOST) of Taiwan to Feng Chia University under MOST-108-2218-E-035-001.