Variable Stiffness Robot Patents: Leaders, Trends & White Space 2026
Filing growth compares 2021 (1 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 150 records in scope (CR5), not by the ranked leaders only.
What the variable stiffness robot patent landscape covers
Variable stiffness robotics covers mechanisms and control approaches that let a robotic joint, limb or wrist change its own compliance on demand — stiff enough to apply force, soft enough to work safely near people or tissue. This landscape draws on 150 published records filed between 2015 and the 2026 data cut-off, spanning general manipulator structures, surgical robotics, control systems and a handful of smaller application branches.
Because publication typically lags filing by around 18 months, the most recent one to two years in any trend chart understate real filing activity. Patent families, not raw document counts, are the fairer unit for judging how concentrated this space actually is, since they filter out repeat continuation filings from a single underlying invention.
Filing trends and technology composition
The 150 records in scope span 2015 through the 2026 data cut-off, with publication lag meaning the most recent two years understate real filing activity.
Filing activity climbed sharply through 2024
Filings ran at 22 in 2017 and peaked at 24 in 2018, dipped through the early 2020s, then grew from 1 in 2021 to 16 in 2024 — a +1500% increase over that span. Figures for 2025 and 2026 are still filling in as publications catch up with filing dates, so they should not be read as a slowdown.
Manipulator claims dominate; medical applications are the strongest secondary cluster
B25J (manipulators & robots) covers 67.3% of the 150 records, far ahead of A61B (diagnosis & surgery) at 27.3%. Control systems, implants, patient transport, physical therapy, springs/dampers and data processing each sit at 8.0% or below, marking them as comparatively open branches rather than crowded ones.
Shares are the percentage of the 150 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Soft Robotics: Variable Stiffness Robot Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about soft robotics: variable stiffness robot patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited and most recent filings in scope
Variable stiffness robot wrist device
A variable-stiffness robot wrist built from a base unit, a fixing unit carrying multiple actuators, a central unit with a socket, a movable unit whose ball joint is inserted into and supported by that socket, and an elastic member whose inner circumference couples to the central unit and outer circumference couples to the movable unit — adjusting joint stiffness through this mechanical arrangement.Filed by the Korea Institute of Science and Technology, published 2025-10-09, illustrating the continued mechanical (rather than purely software) approach to stiffness control that dominates this field.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US8700123B2 | Environment property estimaton and graphical display | 292 |
| 2 | US20140276933A1 | Torque-based catheter articulation | 101 |
| 3 | US20120072026A1 | Robot system controlling method, robot system, and control apparatus for quadrupedal robot | 92 |
| 4 | US20180009116A1 | Variable stiffness robotic joint system | 32 |
| 5 | US20180368664A1 | Robotic materials and devices | 31 |
| 6 | US20110201885A1 | Environment property estimaton and graphical display | 29 |
| 7 | JP1992033006A | Control method for robot system | 29 |
| 8 | US20200297499A1 | Anisotropic Materials in Medical Devices | 21 |
| 9 | WO2010048160A2 | Environment property estimation and graphical display | 20 |
| 10 | US20200206948A1 | Robotic End-Effector Having Dynamic Stiffening Elements for Conforming Object Interaction | 17 |
Citation counts inside this corpus favour older filings and should be read as a signal of influence on later filers, not as a measure of current commercial importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the numbers say about where this field stands
Three findings from the 150 records in scope shape how a filing strategy or freedom-to-operate check should be framed here.
Growth is real, not a data artefact
Filings rose from 1 in 2021 to 16 in 2024. That climb predates the publication lag that makes 2025-2026 look flatter than it will eventually turn out to be.
Leadership is real but not locked up
The top five assignees hold just over a quarter of all records, and the top ten still only 41.3%. Across 84 ranked filers, most hold only a handful of records each.
Mechanical manipulator claims dominate
Two-thirds of records sit in general robot/manipulator structure claims. Surgical applications (A61B, 27.3%) are the only other cluster of comparable size.
US and PCT lead receiving offices
The United States receives the largest share of filings at 58 records, with WIPO/PCT (22) and the EPO (17) next, ahead of Canada, China and India.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to soft robotics: variable stiffness robot patent landscape, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Johns Hopkins University | YAMAMOTO TOMONORI | 2 |
| Johns Hopkins University | VAGVOLGYI BALAZS PETER | 2 |
| Johns Hopkins University | OKAMURA ALLISON MARIKO | 2 |
| TransEnterix Surgical, Inc. | MAQUET GmbH | 2 |
| TransEnterix Surgical, Inc. | Auris Health, Inc. | 2 |
| University of Plymouth | FIELDWORK ROBOTICS LTD | 1 |
Co-assignee activity is limited to 6 pairs across the dataset, with the strongest recurring pairings built around a small number of individual inventors tied to one university — most other work in the field is filed by single institutions rather than joint ventures.
Where to take this analysis next
The figures above set the boundaries of the field. Turning them into a filing or freedom-to-operate decision means going deeper into specific claim sets and assignee portfolios.
Check freedom-to-operate against the densest claims
B25J manipulator claims cover 67.3% of the 150 records in scope. Before filing a mechanical variable-stiffness design, run it against the most-cited records in that cluster.
Run a claim comparison in EurekaTrack the assignees building repeat portfolios
With 84 ranked filers and the top ten holding 41.3% of records, watching which of them keeps filing in 2025-2026 will show where the field is consolidating.
Set up assignee monitoring in EurekaMap the under-claimed branches
Control systems, implants, patient transport, physical therapy and data-processing branches each sit under 8% of records — worth a closer look before assuming the space is crowded everywhere.
Explore white space in EurekaFrequently asked questions
The assignee ranking covers 84 companies and institutions across the 150 records in scope, with the leading filer holding 10 records. The ranked leaders are not overwhelmingly dominant: the top five together account for 26.0% of all 150 records and the top ten for 41.3%, so holding is concentrated but far from monopolised. A long tail of single- or few-filing entrants, including universities and medical device makers, fills out the rest of the ranking.
The largest cluster of filings, 67.3% of the 150 records, sits under B25J and covers general manipulator and robot-arm structures where stiffness is adjusted mechanically at a joint. The second-largest cluster, 27.3% of records under A61B, covers surgical and diagnostic applications such as catheter articulation and robotic surgical tools. Smaller clusters cover implants, patient transport, physical therapy and control systems, each below 5% of records, showing that most patented activity is mechanical-structural rather than software-driven.
Filings grew from 1 in 2021 to 16 in 2024, a documented +1500% increase, and 2024 is the most recent year that can be treated as a complete filing-year figure. Counts for 2025 and 2026 appear lower only because publication typically lags filing by about 18 months, not because activity has actually dropped. Based on the complete years available, the trend through 2024 is one of sustained growth rather than slowdown.
WO2025211519A1, filed by the Korea Institute of Science and Technology and published 2025-10-09, claims a variable-stiffness robot wrist using a ball-joint-in-socket structure paired with a circumferentially coupled elastic member for stiffness adjustment. It constrains designs that follow this specific mechanical arrangement closely, particularly ball-joint wrist mechanisms with an elastic coupling element. It does not extend to variable-stiffness approaches built on different physical principles, such as pneumatic, tendon-driven or granular-jamming stiffness control, which remain open design paths.
The technology composition data shows several branches sitting at or below 4.7% of the 150 records, including implants and prostheses (A61F), patient transport (A61G), physical therapy (A61H), springs and dampers (F16F) and digital data processing (G06F). These are comparatively under-claimed relative to the dominant 67.3% B25J manipulator cluster. Combining a variable-stiffness mechanical claim with one of these secondary applications, or with a dedicated control/data-processing layer, is a route with materially less prior art to clear than a standalone mechanical claim.
Research Soft Robotics: Variable Stiffness Robot Patent Landscape in depth with Eureka
Go past this page: query the whole soft robotics: variable stiffness robot patent landscape corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
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.