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Abstract 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. 

Abstract This study introduces an advanced volumetric additive manufacturing (AM) method, named light-induced direct growth (LIDG), which leverages dual-wavelength photoinitiation and inhibition to push the boundaries of printing complexity. Traditional vat photopolymerization is valued for its high precision in producing detailed polymer structures, yet it is challenged by the need to balance speed and resolution, the reliance on support structures for complex geometries, and issues with material stability during the fabrication process. The volumetric LIDG technique effectively addresses these limitations through the innovative use of dual-wavelength light sources: blue light initiated photopolymerization, while UV light provides selective inhibition. This dual-wavelength system enables targeted polymerization, allowing for the rapid fabrication of complex, overhanging structures without additional support, thus significantly enhancing the efficiency of the printing process. Additionally, this study explores refined resin formulations and optimized curing methods, which contribute to improved stability and uniformity of the printed materials. These advancements make the LIDG method particularly well-suited for applications in fields that demand high precision and material integrity, such as optics, medical implants, and soft robotics. Overall, the LIDG approach with dual-wavelength control represents a substantial breakthrough in volumetric AM, overcoming the inherent constraints of conventional methods and enabling the faster, more accurate production of intricately detailed components across a range of applications.