Capacitive Deionization Interface Engineering Patents: Who Leads, Gaps 2026
- Filing has cooled since 2018. The peak year was 2018 at 9 families, and the trend runs flat or declining through the midpoint year 2022, which saw zero filings in this dataset.
- One corporate cluster dominates co-filing. Unilever-linked entities account for the strongest co-assignee pairs in the dataset, out of only 7 co-assignee pairs total — most applicants file alone.
- Claims concentrate outside the core water-treatment class. Beyond the 52 C02F records that define the search, secondary activity clusters in inorganic compounds (C01B), capacitors (H01G) and conductors (H01B) — a sign that interface chemistry and electrode materials, not system design, are where filers are staking claims.
What this landscape covers
This dataset isolates patent families at the intersection of capacitive deionization (CDI) and interface engineering — filings that specifically address the electrode-solution interface, membrane-electrode interface or surface functionalization, rather than CDI system design in general. The search combines title/abstract terms for CDI and membrane-CDI with claim-description language on interfaces and surface treatment, restricted to the IPC subclasses covering water deionization electrodes and capacitor structures. The result is a narrow, deliberately filtered slice: 52 published families across a data window from 2015 through mid-2026.
Because publication typically lags filing by around 18 months, the most recent one or two years in any trend chart will always look thinner than they eventually turn out to be — this is a data artefact, not necessarily a real drop-off. Readers should treat the 2025-2026 figures as provisional rather than final.
Filing trend and technology composition
Two views of the same 52-family dataset: how filing activity has moved year over year, and which IPC subclasses the underlying inventions actually sit in once you look past the core water-treatment classification.
A flat-to-declining filing curve
Filings ran at 6 in 2017 and peaked at 9 in 2018. By the midpoint year, 2022, filings had dropped to zero, and the curve does not recover to earlier levels through the end of the window at 2026. Combined with the publication lag, this pattern is more consistent with a technology area that had a defined burst of interface-engineering activity around 2017-2019 than with a fast-growing field.
Interface claims lean on materials science, not just water treatment
Every record in this set carries a C02F classification by construction of the search, but secondary classifications tell the real story: 9 records also touch C01B (non-metallic elements and inorganic compounds), 8 touch H01G (capacitors), and 7 touch H01B (conductors and insulators). Filtration (B01D), electrolytic production (C25B) and catalysis (B01J) each appear only once or twice — suggesting those adjacent branches remain comparatively open.
Shares are the percentage of the 52 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Capacitive Deionization Interface Engineering with Eureka
This page is one run against one query. Ask Eureka your own question about capacitive deionization interface engineering and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited records in this space
US10793450B2 — Potential of zero charge-based capacitive deionization
The invention is a capacitive, aka electrostatic, deionization apparatus and method that solves the problem of short lifetime of conventional capacitive deionization (CDI) and of membrane capacitive deionization (MCDI) devices and methods by shifting the Potential of Zero Charge of electrode surfaces through surface modifications. Such electrode surface modifications provide very long lifetime capacitive deionization devices and methods.Assigned to University of Kentucky Research Foundation, granted 2020-10-06. It builds directly on the same applicant's earlier US20160167984A1 filing, which sits among the most-cited records in this dataset.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20140346046A1 | Polarized Electrode for Flow-through Capacitive Deionization | 76 |
| 2 | EP3045431A1 | Apparatus and method for continuous water desalination and ion separation by flow electrode capacitive deioni… | 30 |
| 3 | US20180141834A1 | Single module, flow-electrode apparatus and method for continous water desalination and ion separation by cap… | 24 |
| 4 | US20160167984A1 | Potential of Zero charge-Based Capacitive Deionization | 17 |
| 5 | WO2014090508A1 | Impregnated electrode for capacitive deionisation, process for preparing it and apparatus employing the elect… | 11 |
| 6 | WO2016113139A1 | Single module, flow-electrode apparatus and method for continous water desalination and ion separation by cap… | 10 |
| 7 | EP3647275A1 | Flexible, one-sided membrane-electrode assemblies for use in electrochemical processes, eletrochemical module… | 7 |
| 8 | WO2020094326A1 | Electrochemical module comprising a flexible membrane-electrode assembly | 6 |
| 9 | US20210363015A1 | Capacitive deionization electrode | 6 |
| 10 | EP3424879A1 | Capacitive deionization electrode | 6 |
Citation counts reward older filings simply because they have had more time to accumulate citations within the searched corpus — read them as a signal of influence on later work, not as a ranking of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the dataset actually shows
Four read-outs from the 52-family set, focused on what a filing strategy should take from them rather than restating the raw counts.
Activity clustered, then stalled
The filing curve peaked at 9 families in 2018 and had fallen to zero by 2022, the midpoint of the window. Recent-year momentum tables for every leading assignee show 0 filings in the latest year, though the publication lag means the last one to two years are undercounted.
Influence sits with early flow-electrode work
The most-cited record, US20140346046A1 on polarized electrodes for flow-through CDI, sits well ahead of the next tier. Several of the top-cited records date from the 2014-2016 period, consistent with citation counts favouring older filings rather than signalling where current R&D is headed.
Co-filing is rare and corporate when it happens
Only 7 co-assignee pairs exist across the entire dataset, and the strongest of them links two Unilever-affiliated entities, with a secondary pair linking those entities to Conopco Inc. Most applicants — universities, research foundations, individual companies — file alone.
Materials and capacitor classes carry the interface claims
Beyond the defining C02F classification, secondary IPC activity concentrates in inorganic compound chemistry, capacitor structures and conductor materials. Filtration, electrolytic production and catalysis each register only one or two records, marking them as thin rather than crowded.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to capacitive deionization interface engineering, with the prior art for and against each one.
Who holds the claims
The applicant set is small and dominated by a mix of corporate consumer-goods research arms, European materials institutes and US public university foundations. No single entity shows filing activity in the latest year, consistent with the overall flat-to-declining trend.
Unilever-affiliated entities
Unilever plc and Unilever N.V. form the strongest co-assignee pair in the dataset, with a secondary link to CONOPCO INC, a Unilever US subsidiary. This points to consumer-goods-driven interest in surface functionalization for water treatment.
DWI – Leibniz Institute for Interactive Materials
The DWI Leibniz Institute for Interactive Materials appears among the tracked assignees, reflecting academic materials-science interest in electrode surface chemistry rather than commercial deployment.
University of Kentucky Research Foundation
University of Kentucky Research Foundation holds the featured representative patent on Potential of Zero Charge-based deionization, along with an earlier related filing among the most-cited records — a sustained single-institution research thread rather than a portfolio built through acquisition.
Europe and the US lead filing venues
Europe and the United States each received 14 filings, with WIPO/PCT filings at 6 and smaller counts through Austria, India and the Philippines — a filing footprint typical of research-institute and multinational-corporate applicants rather than a single dominant national market.
| Assignee | Recent year | YoY |
|---|---|---|
| Unilever plc | 0 | — |
| Unilever N.V. | 0 | — |
| DWI – Leibniz Institute for Interactive Materials | 0 | — |
| Tecnalia Research & Innovation Foundation | 0 | — |
| CONOPCO INC | 0 | — |
| University of Kentucky Research Foundation | 0 | — |
| UChicago Argonne, LLC | 0 | — |
| Carnegie Mellon University | 0 | — |
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is freedom-to-operate, licensing or new filing strategy.
Map the thin IPC branches in detail
B01D, C25B and B01J each carry only one or two records here. Before treating them as white space, pull the full claim scope of those records and check whether they block the specific interface configuration under consideration.
Explore with Patsnap EurekaWatch for renewed filing after the lag window closes
The zero-filing years toward the end of the window are partly a publication-lag artefact. Re-run this landscape in twelve to eighteen months to see whether 2024-2026 filings materialise once they clear examination and publication.
Set up monitoring in Patsnap EurekaCheck the Unilever cluster's licensing posture
With the only meaningful co-assignee network in the dataset, the Unilever/Conopco cluster is the one group whose filings are worth reading claim-by-claim for licensing or design-around purposes.
Review assignee portfolios in Patsnap EurekaCommon questions about this landscape
In this landscape, interface engineering covers inventions that specifically modify the electrode-solution interface, the membrane-electrode interface, or apply surface functionalization treatments, rather than general CDI system or cell design. Examples include shifting the potential of zero charge at an electrode surface, coating electrodes with functional layers, or engineering the contact between an ion-exchange membrane and an electrode. This is a narrower slice than the broader CDI patent literature, which also covers flow-cell architecture, module design and control systems.
The dataset shows filings peaking at 9 families in 2018 and falling to zero by the 2022 midpoint, with no recovery through 2026. Part of this decline is a publication-lag artefact, since patents filed in the most recent one to two years typically have not published yet at the time of a data cut-off. But the depth and duration of the drop suggests a genuine slowdown in new interface-specific filing after an initial wave of activity, rather than a data artefact alone.
The dataset's strongest filing relationships involve Unilever-affiliated entities, alongside University of Kentucky Research Foundation and the DWI Leibniz Institute for Interactive Materials on the research-institute side. None of the tracked assignees show filing activity in the most recent year covered by the dataset. Filing venues are split fairly evenly between Europe and the United States, with smaller volumes through the WIPO/PCT route and a handful of national offices.
US10793450B2, assigned to University of Kentucky Research Foundation and granted in October 2020, covers a capacitive deionization apparatus and method that extends electrode lifetime by shifting the potential of zero charge through surface modification of the electrodes. It addresses the specific failure mode of short device lifetime in conventional CDI and membrane-CDI systems. Anyone designing an electrode surface treatment aimed at potential-of-zero-charge shifting for lifetime extension should review this claim set directly rather than relying on the abstract alone.
Based on secondary IPC classification counts, the branches with the thinnest coverage relative to the core water-treatment classification are catalytic surface activation, electrolytic co-production integration, and membrane-filtration hybrid interfaces, each represented by only one or two records in this dataset. That said, thin coverage in a search corpus does not automatically mean the space is legally open — it may simply mean filers are classifying related inventions under different IPC codes. A freedom-to-operate check should still be run against the specific claim language, not just classification density.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.