Hybrid Printing Wrinkle-Free High-Resolution Circuits on Freeform Surfaces Via Adaptive Deformation of a Self-Supporting Mesh.

Conformal circuits on 3D freeform surfaces are of great significance as fundamental components in curved optoelectronic displays, aircraft smart skins, and soft robotics. However, existing methods face significant challenges when producing conformal high-resolution circuits on large curvature and inner curved surfaces. Herein, a novel hybrid printing strategy is introduced that fabricates wrinkle-free high-resolution circuits on freeform surfaces using adaptive deformation of self-supporting mesh. High-resolution self-supporting mesh is fabricated using electric field-driven jetting 3D printing, which exhibits a degree of malleability in water to maintain structural integrity. Leveraging gravity and water flow, the self-supporting mesh conforms to curved surfaces and undergoes adaptive deformation, minimizing wrinkles during transfer printing onto non-developable curved surfaces. This ensures wrinkle-free formation in critical regions and enables conformal high-resolution circuits fabrication on arbitrary outer and inner curved surfaces. The theoretical calculations establish a foundation for the transfer printing process by determining stretch energy, bending energy, and adhesion energy between the self-supporting mesh and the surface. Finally, innovative applications such as an inner curved heated defogging camera and a transparent microstrip antenna on a curved surface demonstrate the feasibility of this manufacturing strategy.