Highly transparent, conducting, body-attachable metallized fibers as a flexible and stretchable film

• Published in: Journal of alloys and compounds 2019-06, Vol.790, p.1127-1136
• Main Authors: Kim, Yong Il, An, Seongpil, Kim, Min-Woo, Jo, Hong-Seok, Kim, Tae-Gun, Swihart, Mark T., Yarin, Alexander L., Yoon, Sam S.
• Format: Article
• Language: English
• Subjects: Contact resistance; Core-shell fibers; Electric contacts; Electric fields; Electrical junctions; Electrical resistivity; Electroplating; Flexible electronics; High temperature; Intersections; Mechanical properties; Metallizing; Microfibers; Morphology; Nanofibers; Nanowires; Silver plating; Silver-plated fibers; Transmittance; Transparent conducting films and heaters
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.03.154

Core–shell-structured silver-electroplated nickel microfibers were fabricated via electrospinning and subsequent electroplating for applications including transparent conductive films (TCFs) and heaters. Fabrication protocol generated self-fused junctions at the intersections of overlapping micro-nanofibers. This reduced contact resistance between wires, yielding remarkably high electrical conductivity, which is highly desirable for the aforementioned applications. A very low sheet resistance of less than 0.2 Ω sq−1 with a high transmittance of over 92% was achieved in these structures. A cactus-like morphology of silver-plated microfibers, which dramatically increases surface-to-volume (S/V) ratio and should produce electric field concentration at silver nanowire tips, was also demonstrated. This unique surface morphology could be promising for energy and environmental applications that require large interfacial areas and electric field concentration, but yielded lower transmittance than smooth wires. These cactus-like microfibers were further coated with Cu and Pt to produce hierarchically-structured multimetallic microfibers. The low-resistivity transparent silver micro-nanofiber films exhibited good heating and mechanical properties, as demonstrated in bending and stretching tests. A record high temperature of 209 °C was achieved with a transparent heater based on the Ag microfibers. •Core–shell-structured silver-electroplated microfibers are fabricated via electrospinning and electroplating.•The self-fused junctions micro-nanofibers enhance electrical conductivity.•A sheet resistance of less than 0.2 Ω sq−1 with transmittance of over 92% is achieved.•The cactus-like morphology of the silver-plated microfibers is demonstrated.