Selectively plated stretchable liquid metal wires for transparent electronics

This paper presents an innovative and versatile selective liquid-metal plating (SLMP) process to realize a transparent stretchable circuit board (TSCB) with the capability of large deformation and self-healing. The TSCB consists of polydimethylsiloxane (PDMS) thin films and non-toxic liquid-metal patterns that are embedded into the PDMS substrate. Complex liquid-metal patterns with various aspect ratios are achieved by using the selective wetting behavior of the reduced liquid metal on the Au/Cr patterns of the PDMS substrate. The smallest liquid-metal pattern is approximately 3 mu m in width. The TSCB integrated with a light-emitting diode exhibit stable performance, even though it is twisted more than 180 degrees or is stretched up to similar to 60% 6000 times. To evaluate the feasibility of the SLMP process, an electrical filter was fabricated on the PDMS substrate and the current-voltage (I-V) characteristics are successfully demonstrated under various conditions. The experimental results reveal that the proposed idea has the potential to enable advanced electronics such as wearable computers, wall-scale displays, electronic paper, and other stretchable electronics. (C) 2015 Elsevier B.V. All rights reserved.