Coaxial Ceramic Direct Ink Writing on Heterogenous and Rough Surfaces: Investigation of Core-Shell Interactions

Traditional direct ink writing struggles with rough or uneven surfaces, limiting the application of sensitive materials. While ceramic inks offer durability for high-temperature environments, their deposition remains challenging on non-uniform substrates. Prior research has shown that encapsulating core materials within a shell can improve printability. However, no prior work had resolved how to maintain structural integrity during printing on complex surfaces. This gap motivated the development of a coaxial printing method. Existing methods often fail to preserve core-shell continuity during extrusion. The need for a reliable approach to coextrude sensitive and encapsulated materials arose from these limitations. Current techniques lack the precision to control core-shell architectures effectively. This study aims to address these shortcomings through a novel ceramic-based printing system.

The goal of this research is to develop a coaxial ceramic direct ink writing system for printing sensitive materials onto irregular surfaces. The specific problem addressed is the difficulty of maintaining core-shell continuity on heterogeneous substrates. The motivation stems from the need to enable high-temperature applications using encapsulated conductive inks. By combining ceramic shells with conductive cores, the study seeks to improve printability on rough surfaces. The approach involves designing a coaxial nozzle to coextrude alumina and indium-tin-oxide inks. The study also aims to explore the interplay between microfluidic coflow and printing performance. The objective is to validate a method that maintains structural integrity during printing. This work contributes to the field by enabling controlled deposition on complex surfaces.

The study employs a coaxial nozzle to coextrude an alumina shell and indium-tin-oxide core. Colloidal inks are formulated to meet rheological and sintering requirements. Flow simulations are conducted using microfluidic coflow principles. The printing system is designed to maintain continuity on rough substrates. Physical modeling is used to analyze core deformations and eccentricity. Experimental validation confirms the effectiveness of the coaxial printing approach. The method integrates simulations with physical testing to optimize printing parameters. The approach enables controlled deposition of core-shell structures on heterogeneous surfaces.

The coaxial printing system successfully deposits core-shell structures onto rough substrates. Simulations and experiments confirm the maintenance of structural continuity. Core deformations and eccentricity are analyzed using physical modeling techniques. The alumina shell effectively encapsulates the indium-tin-oxide core during printing. The method achieves controlled deposition on heterogeneous ceramic surfaces. The study demonstrates the feasibility of high-temperature applications using this approach. Colloidal inks meet the required rheological and sintering performance criteria. The coaxial nozzle design supports reliable coextrusion of ceramic and conductive materials.

The coaxial ceramic direct ink writing method enables printing on rough substrates while maintaining core-shell continuity. The study confirms the effectiveness of microfluidic coflow principles in controlling printing parameters. The developed system supports future high-temperature applications using encapsulated materials. Simulations and physical modeling validate the approach for controlled deposition. The method addresses the challenge of printing on heterogeneous surfaces. The results suggest that this approach can be extended to other ceramic and conductive combinations. The study proposes that the coaxial nozzle design is essential for maintaining structural integrity. The findings indicate that this system improves printability on complex surfaces.