Highly Stable Low‐Temperature Phosphate Glass as a Platform for Multimaterial 3D Printing of Integrated Functional Microfluidic Devices

The monolithic fabrication of microfluidic systems using additive manufacturing technology offers a promising route for integrating the multifunctionality essential to these devices. However, this approach faces key challenges, primarily due to the limited availability of suitable materials and the incompatibility of these materials during the various processing stages. This study introduces a highly stable, low‐temperature phosphate glass for fabricating multifunctional microfluidics via multimaterial additive manufacturing. The synthesized glass powder is formulated into a printable ink using a temperature‐sensitive binder, enabling extrusion‐based printing at room temperature. The selected glass composition, containing 10 wt% F2O3 as an additive and Na2O as a modifier, exhibits high stability (LogDR = −8.47342 g cm−2 min−1 at 25 °C) and a low glass transition temperature (412 °C), enabling the functional integration of multiple materials via multimaterial 3D printing. To demonstrate functionality, a microfluidic device incorporating conductors and a mixer is fabricated, where silver paste is used for conductors, polymer paste is used as a sacrificial material, and glass ink as the structural component. All materials are printed simultaneously, demonstrating monolithic additive manufacturing of microfluidic systems. This approach enables the integration of glass, metal, sacrificial materials, and potentially silicon and electronics, paving the way for advanced multifunctional microfluidic devices.