Embossing of Tapered, Isometric Micro-Interdigitated Flow Fields for Enhanced Desalination by Faradaic Deionization
Abstract
Engineered transport architectures can improve electrolyte distribution and active-material utilization in porous electrodes, yet their implementation remains limited by fabrication methods that compromise precision, throughput, active-material preservation, or scalability. Here, an integrated embossing-calendering method is introduced to pattern Prussian blue analog (PBA) porous electrodes with embedded, micro-interdigitated flow fields (eμ-IDFFs) for electrochemical desalination. This non-subtractive, roll-to-roll compatible method forms channels by controlling plastic deformation while simultaneously calendering the electrode, preserving active material and reducing patterning time by 100-fold relative to mechanical milling. Indentation experiments and a closed-form model further show that embossing requires 15-fold less force than stamping, while electrode microstructures show local densification beneath embossed channels. PBA electrodes are embossed with novel eμ-IDFFs that use continuous width-tapering with isometric flow paths that promote uniform electrolyte distribution, increase rate capability, and reduce polarization. Compared with eμ-IDFFs patterned using less scalable means and non-isometric flow paths, these eμ-IDFFs desalinate seawater-salinity feeds near to potable levels with 1.5-fold of its thermodynamic energy efficiency and water recovery. Brackish desalination benefits similarly. Tapered, isometric eμ-IDFFs and the embossing method introduced to pattern them are readily translated other electrochemical energy storage and separations systems.
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BibTeX
@misc{rahman2026embossing,
title = {{Embossing of Tapered, Isometric Micro-Interdigitated Flow Fields for Enhanced Desalination by Faradaic Deionization}},
author = {Md Habibur Rahman and Sadia Afrin and Kyle C. Smith},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.18791},
eprint = {2610.18791},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.18791},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Embossing of Tapered, Isometric Micro-Interdigitated Flow Fields for Enhanced Desalination by Faradaic Deionization
AU - Md Habibur Rahman
AU - Sadia Afrin
AU - Kyle C. Smith
PY - 2026
DA - 2026/10/13
PB - arXiv
DO - 10.48550/arxiv.2610.18791
UR - https://arxiv.org/abs/2610.18791
AB - Engineered transport architectures can improve electrolyte distribution and active-material utilization in porous electrodes, yet their implementation remains limited by fabrication methods that compromise precision, throughput, active-material preservation, or scalability. Here, an integrated embossing-calendering method is introduced to pattern Prussian blue analog (PBA) porous electrodes with embedded, micro-interdigitated flow fields (eμ-IDFFs) for electrochemical desalination. This non-subtractive, roll-to-roll compatible method forms channels by controlling plastic deformation while simultaneously calendering the electrode, preserving active material and reducing patterning time by 100-fold relative to mechanical milling. Indentation experiments and a closed-form model further show that embossing requires 15-fold less force than stamping, while electrode microstructures show local densification beneath embossed channels. PBA electrodes are embossed with novel eμ-IDFFs that use continuous width-tapering with isometric flow paths that promote uniform electrolyte distribution, increase rate capability, and reduce polarization. Compared with eμ-IDFFs patterned using less scalable means and non-isometric flow paths, these eμ-IDFFs desalinate seawater-salinity feeds near to potable levels with 1.5-fold of its thermodynamic energy efficiency and water recovery. Brackish desalination benefits similarly. Tapered, isometric eμ-IDFFs and the embossing method introduced to pattern them are readily translated other electrochemical energy storage and separations systems.
ER -