Dynamically Conformal Mask Printing of Liquid Alloy Circuits on Morphing Objects

Due to their excellent conformability and inherent compatibility, soft three-dimensional (3D) circuits can promisingly contribute to soft intelligent systems, i.e., soft robots equipped with dynamic and sophisticated morphologies. However, current processing technologies have almost focused on fabricating planar or 3D circuits on static objects, which restrict the feasibility when targeting on dynamic/morphing surfaces in case of mismatched stress or strain. Here, a conformal mask printing method, based on selective laser patterninga conformal, attachable and dynamic (CAD) film made of carbon black-doped polydimethylsiloxane (cPDMS) is reported. Combining with the unique fluidity of liquid alloy, the new CAD-mask allows to conformably print dynamic compliant liquid alloy circuits on various complex and morphing surfaces. To illustrate the capability of the approach, 3D conformal circuits are fabricated on a steering wheel for detecting driving modes, on a face model to achieve anthropomorphic layer, and demonstrate the fabrication process on adynamic shape-changing elastomeric heart and a human hand. The approach offers a new opportunity for real-timely configuring dynamic compliant circuits on morphing substrates of soft electronics/robotics.