Effects of Polymer Matrix Structures on Metallic Growth in Electrically assisted Vat Photopolymerization for Heterogeneous Metal-Polymer Printing

Although metal-polymer heterogeneous structures possess exceptional mechanical, thermal, and electrical properties, their fabrication remains challenging due to the reactive nature of the materials and the risk of property alteration during manufacturing. This study investigates the printing quality of metal-polymer structures fabricated using electrically assisted heterogeneous material printing (EF-HMP), focusing on the relationship between the polymer and metal layers and their electrical properties. The developed printing solution enables the transport of metal ions for metal printing onto a polymer matrix under a controlled electrical field. The study emphasizes the critical role of polymer microstructures in influencing metal electrodeposition, including printing time and morphology. Three microstructure geometries—rectangular, trapezoidal, and semicircular—were designed based on manufacturability and surface-area-to-volume ratio and evaluated for their impact on metal-polymer fabrication via EF-HMP process. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and electrical conductivity tests revealed that the semicircular microstructure provided the best printing performance, forming a robust metal structure in a short time and achieving the lowest resistance of 12 kΩ. This research highlights the potential of EF-HMP for metal-polymer fabrication, offering new insights into the influence of interfacial polymer microstructures on metal printing at room temperature. These findings pave the way for optimizing the design and functionality of metal-polymer components in metamaterials, thermal management, and flexible electronics applications.