Milling or Printing: Enabling Informed Manufacturing Decisions for Fluidic Manifolds through Design Automation

The decision for a manufacturing technology, such as milling or additive manufacturing (AM), is a critical step in manifold design, as it defines design constraints, costs, and performance of the final product. This decision is typically made with limited information, and detailed design variants for comparison are rarely explored due to time and cost constraints. Therefore, engineers rely on assumptions and experience that may lead to suboptimal decisions. This work presents a novel approach for informed manufacturing decisions while significantly reducing the development time. This is achieved through design automation (DA) algorithms that generate detailed designs of fluid manifolds for AM and milling. Both DA algorithms take functional specifications and fluidic components (e.g., valves, sensors) as inputs and auto-generate manufacturing-ready designs. While the AM algorithms have been previously published, new algorithms for the milling process are introduced and described in detail. The key steps are positioning of the fluidic components, collision-free routing of the flow channels under milling constraints, and reducing the block size to minimize material usage. In a case study, four design variants are generated using the algorithms –two for AM and two for milling –based on identical specifications. The variants are compared based on mass, installation space, production cost, and CO₂ emissions. These comparisons highlight the trade-offs between the technologies. These results demonstrate how DA enables rapid, case-specific comparison of variants designed for different manufacturing processes, supporting faster and more informed decisions in early development stages.