SolidWorks for Microfluidics: Extract the Fluid Path, Calculate Volume & Check Continuity

One tiny design mistake. Three weeks lost. A few years ago, I was involved in a project to design and rapidly prototype a fairly complex microfluidic chip. The engineer leading the design made a small mistake in one of the through-holes, interrupting the fluid path. The result? Additional mold costs and, more importantly, a three-week delay. To be fair, the chip was complicated, the team was under pressure, and everyone was working extended hours. These mistakes can happen, even to experienced engineers. I shared an approach I had developed in graduate school to help the microfluidics team catch these issues before fabrication. The idea is simple: model the fluid path as a separate body in SOLIDWORKS. This approach offers several advantages: 💧 Verify flow-path continuity. Select any point along a channel to check whether the fluid region is connected as intended. 📏 Calculate internal volume and dead volume. Measure fluid volume directly from the model, without spreadsheets or manual estimates. For injection-molded parts, this also accounts for draft angles when they're included in the geometry. ⚡️ Accelerate design iterations. Identify problems, measure dimensions, and modify the design before committing to expensive tooling or prototypes. 🧪 Prepare for simulation. Export the fluid geometry for use in simulation tools such as COMSOL Multiphysics. The best time to catch a design mistake is when it's still just a CAD model—not after you've paid for a mold. One final tip for SOLIDWORKS users: Fully define your sketches! It's a simple habit that helps make your designs more predictable and easier to modify. #Microfluidics #SOLIDWORKS #CAD #RapidPrototyping #EngineeringDesign #COMSOL