Simple Alignment Method for CNC Machining Double-Sided Plastics: Unlocking New Design Microfluidic Possibilities

In the world of microfluidics, design freedom and precision fabrication are critical. Whether you're building a simple Y-junction chip or a complex organ-on-a-chip model, the ability to miniaturize and maximize the available real estate on your microfluidic device creates endless possibilities. One approach gaining traction is double-sided microfluidics, where fluidic features are fabricated on both sides of the microfluidic device. CNC machining and 3D printing are both viable techniques for fabricating double-sided microfluidics but when you need to prototype something rigid plastic with a known chemical composition, such as polycarbonate or acrylic, CNC is the superior choice.

This blog post provides a video on how to CNC machine double-sided microfluidic chips with links to download the 3D CAD model for reference.

What Is Double-Sided Microfluidics?

Double-sided microfluidics refers to devices where fluidic features are present on both the top and bottom surfaces of the device. These features can connect using through holes (or vias), enabling more complex 3D fluidic networks. Benefits include:

• Compact designs with layered fluid routing
• Integrated valves or reservoirs on opposite faces
• Simplified interfacing (e.g., fluidic inputs on one side, sensing or actuation on the other)

Applications range from lab-on-a-chip systems and point-of-care diagnostics to advanced organ-on-chip platforms where multiple cell culture environments must be fluidically isolated yet interconnected.

Simple Technique to CNC Machine Double-Sided Microfluidics using Dowel Pins and the Spoilboard

CNC machining double-sided microfluidics follows the same work flow as single-sided but after machining on Side 1, the part is flipped, alignment holes for dowel pins are machined in the bed, the part is resecured onto the dowel pins in the bed, and features are machined on Side 2. The part where many users mess up is configuring the coordinate system for Side 2. It is easier to provide an example of the part setup than it is to explain the concepts so feel free to download the reference file to see the CAM configurations.

The video demonstrates the process for CNC machining double-sided microfluidic chips using dowel pins by drilling the matching alignment features directly into the spoilboard.

Final Thoughts

CNC machining is a must-have skill for any microfluidics engineer or scientist. Combined with 3D printing, the possibilites are endless. Whether you’re a biologist exploring new assay formats or a startup racing toward MVP, it’s worth considering CNC micromachining as a rapid, precise, and surprisingly accessible fabrication method.

If you're curious about getting started, or are looking for low-quantity CNC chips, contact us today!

Fusion Reference File Download