Desalination by electrodialysis using a stack of charged hydrogels in a microfluidic platform

We show a new approach for desalinating water, using a stack of periodic hydrogel structures in a microfluidic platform. This technique utilizes alternating anion- (AEH) and cation-exchange hydrogels (CEH) locally fabricated in confined compartments by capillary line pinning. Parallel streams of concentrated and ion-depleted water are formed in continuous flow when applying a potential difference across the microchip. Different electric fields (10-100 V/cm) and fluid flow rates (0-5 μl/min) are investigated.