Three-dimensional liquid metal circuits enabled by deformation-programmable substrate

With the development of electronic devices towards miniaturization and high performance, traditional planar circuits have gradually failed to meet the growing space and functionality requirements. In this work, based on the deformation-programmable film, an innovative liquid metal three-dimensional (3D) circuit fabrication method is proposed, which can transform the planar circuits into 3D circuits. The shrinkage of the deformation-programmable film was precisely controlled by converting it to a partially shrinkable film by introducing a non-shrinkable zone, and the interconnection of circuits on three-dimensional structures was realized by taking advantage of the low mobility and high compliance of semi-liquid metals. Circuits with a variety of three-dimensional structures were fabricated using this technique. This work details the deformation of partially shrinkable films, the rheological properties of semi-liquid metal, and the key parameters in the manufacturing process. The 3D circuits fabricated in this work show excellent electrical properties and mechanical stability (the conductivity is 9 × 10⁶ S/m, and the resistance shows less than 2% loss after 5000 bending cycles). In addition, we demonstrate the potential application of this technique in curved conformal electronic devices. The research in this paper not only provides a new method for fabricating 3D circuits but also opens up new possibilities for the design and fabrication of future electronic devices.