Heterogeneous Surface Orientation of Solution-Deposited Gold Films Enables Retention of Conductivity with High Strain - A New Strategy for Stretchable Electronics
Chemistry of Materials
Stretchable electronic devices rely on stretchable conductors to form device interconnects and electrodes that maintain electrical performance during deformation. Although the high conductivity of metals makes them desirable materials for these applications, the lack of intrinsic stretchability of metals is a fundamental problem in stretchable electronics. Research efforts to impart stretchability to metal films on elastomers have involved configuring the films into wavy features that unbend with strain or using high surface roughness to engineer how cracks form in metal films under strain. However, the topographies used in these approaches cause problems with integrating these metal films as electrodes in thin-film devices. This paper presents a new, simple, and low-cost strategy for the fabrication of stretchable gold films with planar topography that remain highly conductive to 95% elongation. Using solution-based electroless plating to deposit gold films on the elastomer poly(dimethylsiloxane) results in a heterogeneous crystalline surface texture with misoriented grains that are strong barriers to dislocation movement. Under strain, the misoriented grains cause the formation of a unique nanoscale cracking pattern that is remarkably effective at preserving conductivity. We demonstrate that this performance, coupled with the planar topography of these gold films, makes them suitable as electrodes in intrinsically stretchable light-emitting devices.
Chen, Yiting; Wu, Yunyun; Mechael, Sara S.; and Carmichael, Tricia Breen. (2019). Heterogeneous Surface Orientation of Solution-Deposited Gold Films Enables Retention of Conductivity with High Strain - A New Strategy for Stretchable Electronics. Chemistry of Materials, 31 (6), 1920-1927.