My first chip had no channels

The first microfluidic chip I printed came off the printer solid. Resin had stayed trapped inside the channels and cured during the print, filling them in. The resin was transparent, so I could see exactly what had happened.

I wanted to design chips that work on the first print, so I built an app for it. It’s called OpenChip, and it’s now open source.

What it does

OpenChip is a design tool for microfluidic chips made on consumer resin printers. You draw a channel network in the editor. OpenChip estimates flow and pressure, flags geometry that is likely to fail in print, and exports STL, OpenSCAD, or SVG files. Everything runs in your browser, and your designs never leave your computer.

The repo also includes a skill for coding agents. With it, an agent like Claude Code can design and export chips from a plain description.

What it can’t do yet

The fluid model is one-dimensional. Printing adds its own error, because channels shrink and over-cure. My next project is measuring how far real printed chips drift from the model.

Credit

Dr. Walker MacSwain, a postdoc in Dr. Xi Chen’s lab at CUNY ASRC, started this. He asked if I could make some microfluidic chips for his project. We worked out the feature set and guiding principles together, and he validated the software and many of the designs.

You can use it at openchip.tech and read the code on GitHub. If you design chips, work with microfluidics, or own a resin printer, email me what you think.