Fully Printed Multilayer Flexible Structure for 3D Assembly on Irregular Substrates for Hybrid Electronics

ABSTRACT In this study, a functional multilayer structure is manufactured for 3D assembly onto a three‐dimensional irregular surface. Conformal flexible devices are printed using Piezojet, screw ink dispenser, and doctor blade coating techniques onto stretchable TPU film. Silver‐flake ink is used as the conductive material, and acrylic‐based dielectric ink is used as an insulator between conductive layers. Two approaches are proposed to achieve the multilayer stack: selective coating, where dielectric ink is dispensed at interlayer connection points, and a blade coating approach, where the dielectric material is distributed over the desired area. Electrical insulation was achieved only by blade coating for dielectric wet thicknesses between 50 and 100 µm. 3D assembly of multilayer samples was performed using heat‐bed lamination on a PCB. Samples achieved surface adaptability at a process temperature of 120°C, maintaining electrical functionality. The novelty of this work lies in the process development for the integration of an additive‐manufactured, fully printed multilayer device that is successfully laminated onto a rigid three‐dimensional structure with an irregular surface profile, while preserving electrical insulation and functionality. Providing opportunities for functional expansion and hybrid electronics development.