Commercial ion exchange membranes list at roughly $229 to $242 per square foot. That single cost line keeps a lot of electrochemistry out of reach for small labs, recyclers, and independent researchers. So we built one that almost anyone can make, and we put the recipe online for free.
What it is
Our membrane is cast from pulverized water softener resin dispersed in PVC cement. The materials are off the shelf, the process is simple, and the finished sheet costs about $0.99 per square foot at 160 microns dry thickness. It is the same membrane we use inside S.E.M Technology, our salt-based electrochemical recovery process.
Ion exchange membranes sit at the heart of a lot of clean technology, from redox flow batteries and fuel cells to electrolysis and metal recovery. Bringing their cost down opens all of that up to far more people.
Why we open-sourced it
Breakthrough tools only reach their potential when people can actually use them. We released the membrane design under the CERN-OHL-S license so anyone can build it, study it, and improve it. Independent builders are already replicating it, and the work was covered by Hackaday and the science channel NightHawkInLight.
Build it yourself
The full formulation, materials list, and assembly steps are on our GitHub repository. If you try it, tell us how it goes. We share our failures too, and yours will help the next person.