Hydrogen Leak Detection Patents: Who Leads, Trends 2026
- Filing has cooled since a 2017 peak of 24 families, with the 2022 midpoint at 13 — a flat-to-declining trend rather than a growth curve, even before the last two partial years are discounted for publication lag.
- G01N testing methods dominate at 340 of 346 families, while fuel-cell (H01M, 36) and vehicle propulsion (B60K, 11) filings are a distinct minority — most protection sits on the sensor itself, not on vehicle integration.
- The United States (99) and China (85) lead receiving offices, ahead of the EPO (57) and PCT (37), pointing to two largely separate regional prosecution tracks rather than one global filing strategy.
Filing growth compares 2021 (9 records) with 2024 (16) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 346 records in scope (CR5), not by the ranked leaders only.
What the hydrogen sensing patent record actually shows
Hydrogen leak detection sits at the intersection of gas sensing chemistry and safety-critical vehicle and infrastructure engineering. The 346 patent families in this dataset span 2015 through mid-2026, concentrated overwhelmingly under G01N — material analysis and testing — with fuel cell (H01M), catalysis (B01J) and vehicle propulsion (B60K) as secondary but present threads. That composition tells a specific story: the sensing element itself, not the vehicle or refuelling-station integration around it, is where most claim activity has landed.
Filing peaked in 2017 and has not recovered since; the 2022 midpoint of 13 families sits roughly half the peak. Because publication typically lags filing by around 18 months, the last one or two years in the trend understate real activity, but the multi-year decline predates that lag and looks structural rather than an artefact of the data cut-off.
Filing trend and technology composition
Two views of the same 346-family dataset: how filing volume has moved year over year, and how that volume is distributed across the IPC subclasses that touch hydrogen sensing.
A 2017 peak followed by a multi-year decline
Filings ran at 24 families in 2017, the highest point in the series, and by the 2022 midpoint had fallen to 13. The slide continues into the most recent partial years, though those figures will revise upward as later publications catch up.
Sensing and testing methods dominate the IPC mix
G01N accounts for 340 of 346 records, an almost universal tag across the dataset. H01M (36), B01J (22), G01M (19) and B82Y (15) form a secondary tier tied to fuel-cell chemistry, catalytic sensing and nanomaterial sensor construction; B60K vehicle-propulsion filings (11) are the smallest and most integration-specific slice.
Shares are the percentage of the 346 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Gas Sensing for Hydrogen Leak Detection with Eureka
This page is one run against one query. Ask Eureka your own question about gas sensing for hydrogen leak detection and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited records anchor the sensor architecture debate
Hydrogen sensor mounting structure for fuel cell vehicle (US20060269806A1, Honda)
The filing covers a hydrogen sensor mounting structure for a fuel cell vehicle, placing the sensor above a fuel cell system located under the floor panel, mounted from inside the cabin at the floor tunnel portion.This is a placement and structural-integration claim rather than a sensing-chemistry claim — it protects where the sensor sits in the vehicle, not how the sensor itself detects hydrogen.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US6596236B2 | Micro-machined thin film sensor arrays for the detection of H2 containing gases, and method of making and usi… | 141 |
| 2 | US6265222B1 | Micro-machined thin film hydrogen gas sensor, and method of making and using the same | 131 |
| 3 | US6029500A | Piezoelectric quartz crystal hydrogen sensor, and hydrogen sensing method utilizing same | 100 |
| 4 | US20040261500A1 | Method and apparatus for sensing hydrogen gas | 74 |
| 5 | US20030153088A1 | Micro-machined thin film sensor arrays for the detection of H2, NH3, and sulfur containing gases, and method … | 60 |
| 6 | US5670115A | Hydrogen sensor | 60 |
| 7 | US20020017126A1 | Micro-machined thin film sensor arrays for the detection of H2, NH3, and sulfur containing gases, and method … | 59 |
| 8 | US20040173004A1 | Robust palladium based hydrogen sensor | 55 |
| 9 | US6293137B1 | Hydrogen sensor | 53 |
| 10 | US20050155405A1 | Method and device for diagnosing gas sensor degradation | 52 |
Citation counts reflect influence within the searched corpus and skew toward older filings; treat them as a map of foundational architectures, not of current commercial priority.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns worth acting on: the trend's direction, where the IPC weight actually sits, and what the most-cited prior art protects.
The growth phase has already passed
The 2017 peak of 24 families has not been matched since, and the 2022 midpoint of 13 confirms a genuine decline rather than noise. A new entrant is filing into a field where activity is thinning, not accelerating — useful context before assuming this is a growth category.
Almost everything sits under material testing
G01N's near-universal presence means the sensing method and material claims are the dense zone. Secondary IPCs — H01M, B01J, B60K — are comparatively open by volume, even though they touch the same underlying hydrogen safety problem.
Micro-machined thin-film architectures anchor the field
The most-cited records are thin-film and piezoelectric sensor architectures from the early 2000s. Their high citation counts reflect their age and foundational role, not that they remain the state of the art a new filer must clear today.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to gas sensing for hydrogen leak detection, with the prior art for and against each one.
A fragmented field with no filer currently accelerating
Recent-year momentum across the tracked assignees is flat: every major name in the ranking shows zero filings in the latest year, consistent with the broader decline in the trend line rather than a rotation between competitors.
Honda's structural patents predate the current slowdown
Honda's fuel-cell-vehicle sensor mounting patent (US20060269806A1) is one of the field's representative filings, but Honda shows no recent-year activity in this dataset, mirroring the wider pullback rather than an isolated pause.
Collaboration is thin and concentrated on one filer
Only ten co-assignee pairs exist across the dataset, and the strongest three all share the same lead entity paired with different named inventors — a single-organisation inventor network rather than a broad industry collaboration.
Two separate prosecution tracks, not one global strategy
The US and China lead as receiving offices by a narrow margin, with the EPO and PCT well behind. That split suggests most applicants are pursuing regional protection rather than routing broadly through PCT.
| Assignee | Recent year | YoY |
|---|---|---|
| Nanomaterials Technology Co., Ltd. | 0 | — |
| Honda Motor Co., Ltd. | 0 | — |
| Mikuni Corporation | 0 | — |
| Reactor Resources LLC | 0 | — |
| Panasonic Intellectual Property Management Co., Ltd. | 0 | — |
| Advanced Technology Materials, Inc. | 0 | — |
| The 48th Research Institute of China Electronics Technology Group Corporation | 0 | — |
| General Motors LLC | 0 | — |
Where to take this analysis
The dataset points to a mature, slowing filing base with concentrated claim density in sensing methods and a thinner layer around vehicle and station integration. Two directions follow from that.
Map the white space before drafting
The gap between G01N's 340 records and the much smaller B60K and F04D counts is where integration-level claims — mounting, purge, cross-sensitivity compensation — remain comparatively open. A freedom-to-operate check should start there, not in the crowded core.
Explore white space in EurekaTrack assignee momentum, not just rank
With every major assignee at zero filings in the latest year, the ranking table reflects historical position more than current activity. Watch for the first entity to break that pattern rather than assuming today's leaders will keep filing.
Monitor assignee activity in EurekaCommon questions on hydrogen leak detection patents
The ranking in this dataset is led by a small group of assignees including Honda, Panasonic Intellectual Property Management, and several China-based and Taiwan-based sensor specialists, but none of the tracked leaders show any filings in the most recent year. That means the ranking reflects accumulated historical filing rather than current competitive activity, so a company's position at the top of the table is not a reliable signal of where new claims are being written today.
Slowing, based on the filing-year trend: activity peaked at 24 families in 2017, fell to 13 by the 2022 midpoint, and has continued to decline since. Publication lag of roughly 18 months means the final one or two years will revise upward, but the multi-year direction before that lag kicks in is clearly downward rather than flat or growing.
G01N, the material analysis and testing subclass, covers 340 of the 346 families in this dataset — effectively the entire field. Secondary technology threads sit under H01M (fuel cells, 36 records), B01J (catalytic processes, 22), G01M (structural testing, 19) and B82Y (nanotechnology, 15), with vehicle-specific integration under B60K the smallest tier at 11 records.
Honda's US20060269806A1 claims a specific structural arrangement — a hydrogen sensor mounted above a floor-tunnel-located fuel cell system, accessed from inside the cabin — rather than a sensing method or chemistry. It constrains that particular mounting geometry for fuel-cell vehicles specifically, but it does not block hydrogen sensing approaches generally, nor placements outside that floor-tunnel configuration, nor non-automotive applications such as refuelling stations or industrial leak detection.
The volume gap between the dense G01N core and the thinner B60K (vehicle propulsion, 11 records) and F04D (pump integration, 12 records) tiers points to under-claimed territory around vehicle and infrastructure integration rather than the sensing element itself. Cross-sensitivity compensation for mixed-gas environments and refuelling-station-specific sensor array configurations are two areas with comparatively few dedicated filings relative to their practical importance.
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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.
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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.