US 10935404

I'll search for authoritative information on this patent and any litigation/docket activity.

Let me check specifically for litigation/docket activity and USPTO records for this patent.

US Patent 10,935,404 — Summary

Note on method: I could not directly query USPTO Patent Center or the CAFC docket system. I relied on the full patent text provided (fetched from Google Patents) plus web searches. Searches for the specific number in litigation/appeal contexts returned no district-court or Federal Circuit activity for this patent. Treat the "no litigation" conclusion as a negative search result, not a certified clearance.

Bibliographic data (literal)

Abstract (as published)

A MEMS sensor for measuring at least one measured variable (e.g., density, flow and/or viscosity) of a flowing fluid. It comprises at least one microfluidic channel having a channel section excitable to oscillate, and an exciter system for exciting a desired oscillation mode in which the channel section oscillates in a predetermined plane of oscillation. Improved oscillation characteristics are achieved in that the channel section is composed of an anisotropic material with directionally dependent elasticity, spatially oriented so that the modulus of elasticity governing stiffness against deflections perpendicular to the plane of oscillation is greater than the modulus governing stiffness against deflections in the plane of oscillation.

Independent claim — plain-language overview

There is exactly one independent claim: claim 1 (claims 2–8 all depend on it). No method claim was granted, even though the specification recites a wafer-based manufacturing method.

Claim 1 (apparatus): A MEMS sensor for measuring density, flow and/or viscosity of a fluid, comprising:

1. A first microfluidic channel with a longitudinal axis and a first channel section excitable to oscillate;
2. An exciter configured to excite an oscillation mode causing that channel section to oscillate in a predetermined plane of oscillation;
3. The channel section is made of an anisotropic material with directionally dependent elasticity, oriented so that its perpendicular-to-plane modulus > in-plane modulus (i.e., stiffer out of plane, more compliant in plane); and
4. A stated functional result: via that material orientation, either (a) a disturbance mode is suppressed by increasing stiffness perpendicular to the plane of oscillation, or (b) measuring sensitivity is increased by lowering stiffness in the plane of oscillation.

Point to watch: Limitation 4 is phrased as an effect/result rather than a structural feature ("wherein via the orientation of the material a disturbance mode is suppressed by … or a measuring sensitivity is increased by …"). Because it is drafted in the alternative ("or"), each branch is independently satisfied. This kind of functional/result language is a common validity-pressure point (e.g., clarity/enablement, or whether it adds patentable weight beyond limitation 3).

Dependent claims in brief:

• Claim 2 — anisotropic material is silicon or silicon-based; crystal structure oriented so the crystal direction runs parallel to the channel section's longitudinal axis and parallel to the surface normal of the plane of oscillation. ⚠️ Literal-text flag: in the granted claim text I retrieved, the specific Miller indices are absent/blank ("the direction of the crystal structure"), whereas the specification specifies (110) parallel to the longitudinal axis and (001) parallel to the surface normal. I am reporting the claim text as retrieved rather than silently inserting the indices; the published EP/DE family and WO abstract do recite (110)/(001). This looks like an omission in the rendered claim text, but I cannot certify the as-issued printed claim from here.
• Claim 3 — the anisotropic material is doped silicon.
• Claim 4 — the channel section's height (perpendicular to plane of oscillation and to the longitudinal axis) is greater than its width (a "tall" cross-section, FIG. 4; spec example ≈ 300 µm height × 150 µm breadth).
• Claim 5 — adds a second, parallel microfluidic channel with its own oscillatable channel section; both channels on two spaced supports, both sections suspended between the supports and made of the anisotropic material; exciter excites both, in the plane of oscillation (spec prefers opposite-phase excitation). (Minor literal-text note: claim 5 says "the exciter system" while claim 1 introduced "an exciter.")
• Claim 6 — the first channel is a U-shaped channel on two spaced supports, with two parallel, spaced channel segments joined by a third connecting segment; the first and second segments contain the two channel sections (both suspended, both anisotropic material); exciter drives them in opposite-phase oscillations in the plane of oscillation.
• Claim 7 — the channel has an inlet and an outlet for flow-through in measurement operation.
• Claim 8 — a measurement system that metrologically registers a property of the oscillations dependent on a fluid physical property (mass flow, density and/or viscosity) and derives the measured variable; exciter excites the desired mode in measurement operation.

Technical gist (for context)

• Standard twin-tube Coriolis disturbance-mode suppression (per cited U.S. Pat. No. 5,731,527, Micro Motion) uses added fiber-reinforced composite strips — the patent explains this is not directly transferable to microfluidic MEMS channels.
• The invention instead exploits silicon's intrinsic anisotropy: with Si(110) along the channel longitudinal axis and Si(001) normal to the oscillation plane, the relevant modulus along [110] is ≈ 169 GPa versus ≈ 130 GPa along [100], separating the desired-mode eigenfrequency from the perpendicular "disturbance" mode eigenfrequency and raising sensitivity.
• Manufacturing (spec, not claimed): DRIE-formed U-profiles in a first (001) wafer, bonded to a second wafer, second wafer thinned/etched back to form the fourth channel wall.

Litigation / CAFC 2026 docket check

• No results tying US 10,935,404 to any district-court action or Federal Circuit appeal, including any 2026 CAFC docket. Keyword searches combining the number with "litigation," "CAFC," or "Federal Circuit" returned only unrelated hits (municipal records, an unrelated API well number, a European research grant number).
• I did not find any recorded patent assignment beyond the original inventor→TrueDyne Sensors AG assignment (recorded 2018-04-27, effective 2018-02-14).
• Uncertainty: absence of search results is not proof of no litigation. A definitive answer requires a live USPTO Patent Center / PACER / CAFC docket lookup, which I could not perform. I also cannot confirm whether an EPO opposition was filed against family member EP 3368867 B1.

Confidence

• Bibliographic data, abstract, and claim scope: high — taken directly from the provided authoritative patent text.
• Miller indices in granted claim 2: low/uncertain — the retrieved claim text omits them; specification and family publications recite (110)/(001).
• Litigation/docket status: low — no evidence found either way beyond negative search results.

I'll search for litigation involving US patent 10935404.

Let me try more targeted searches on litigation-specific sources.

Litigation Search Report — U.S. Patent No. 10,935,404

Patent under review: US 10,935,404 B2 ("MEMS sensor for measuring at least one measured variable")
Current assignee of record: TrueDyne Sensors AG (Switzerland)
Priority date: 2015-10-27 · Filing date: 2016-09-12 · Grant date: 2021-03-02 · Adjusted expiration: 2037-08-21

Finding

No litigation involving U.S. Patent No. 10,935,404 was found.

I searched for district court complaints, Section 337 (ITC) investigations, Federal Circuit appeals, and PTAB proceedings naming this patent, using the specific number 10935404 / 10,935,404 and assignee-based queries (TrueDyne Sensors AG). I did not locate any case list, docket entry, PACER/courtlistener record, CAFC opinion, ITC determination, or Unified Patents litigation entry identifying this patent number or the TrueDyne/Endress+Hauser family as an asserted patent.

What the searches did and did not show

Important caveat on false positives: My searches returned several unrelated matters that use a "'404" shorthand. Per your strict instruction, I did not auto-substitute these for 10,935,404:

• Chamberlain Group v. ITC (Fed. Cir. 2020-1965 / 20-1965, opinion Apr. 27, 2023) — concerns a movable barrier operator '404 patent, not this one.
• Allergan, Inc. v. Sandoz/Akorn (M.D.N.C. 1:14-cv-01034) — concerns U.S. Patent 7,351,404.
• CBP ruling H344639 — also the Chamberlain '404 patent.

None of these involve US 10,935,404.

Contextual notes (non-litigation)

• The patent belongs to the TrueDyne/Endress+Hauser extended family. A Dutch patent-register (RVO Hoofdblad IE) entry lists TrueDyne Sensors AG and Endress+Hauser Flowtec AG with inventors REITH/HUBER/FETH and German priority 102015118346 — this reflects an assignment/co-ownership record, not litigation.
• The patent's family members include EP3368867B1, CN108351244B, ES2875754T3, WO2017071864A1, DE102015118346A1. No opposition or litigation data for these was surfaced either.

Conclusion and limitations

Based on the available searches, there is no known litigation involving US 10,935,404 as of the current date. Accordingly, no plaintiff, defendant, jurisdiction, case number, filing date, or outcome can be reported.

Recommended verification steps before relying on this conclusion:

1. Direct query of the Unified Patents litigation portal (https://portal.unifiedpatents.com/litigation) by patent number.
2. PACER / CourtListener RECAP full-text search restricted to the exact number 10,935,404.
3. USPTO PTAB (PTAB Center) and USPTO Patent Center "Litigation" tab for the '404 patent.
4. ITC EDIS search for Section 337 complaints naming the patent.

Because this conclusion rests on the search results available to me and not on an exhaustive docket-by-docket review, I flag that a very recent or low-visibility case could exist that my searches did not surface. I cannot confirm a negative with absolute certainty.

I'll verify the ODP "no proceedings" signal against public sources before concluding.

Let me try a few more targeted searches to be thorough about litigation-driven or aggregator filings.

The "'404 Patent" hits in that search are a different patent (a cardiac-tissue-modulation patent litigated in W.D. Tex. with Argenta art) — not TrueDyne's MEMS patent. Let me confirm the distinction and do one final absence check.

PTAB proceedings on file — US 10,935,404 B2

Verification note: The ODP structured feed reports no AIA trial proceedings. I ran independent web searches (patent number + PTAB/IPR/PGR/CBM; assignee TrueDyne Sensors AG; Endress+Hauser; aggregator check) and found no IPR, PGR, or CBM petition naming US 10,935,404 B2. One important caution: search surfaced an IPR petition discussing a "'404 Patent" with Argenta cardiac-tissue-modulation art, an ex parte appeal (Appeal 2018-002533), and a 2024 W.D. Tex. suit (see PTAB petition 1557943). That is a different patent — it issued 2020-05-05, whereas US 10,935,404 B2 granted 2021-03-02 — and is not the TrueDyne MEMS sensor patent. Do not treat those hits as proceedings against this patent.

Proceedings overview

Total AIA trial proceedings on file: 0 — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution denials. All eight claims of US 10,935,404 B2 (claims 1–8) are untested at the PTAB; the patent has never been challenged in an AIA trial, so it stands un-narrowed and, from a defendant's perspective, unhardened but also un-weakened — there is no PTAB record either helping or hurting you.

Bottom line for a defendant: You get no free kill from a prior IPR, but you also face no § 315(e) estoppel (no petitioner exists), no FWD findings, and no claim-cancellation certificate. Any one of claims 1–8 is still live. This is a "clean-slate" patent — an IPR is available to you on any § 102/§ 103 ground if you have the art.

Strategic summary

Claim status. There is no PTAB-derived narrowing. Claims 1–8 are all UNTESTED. Claim 1 is the sole independent claim (a MEMS sensor with a microfluidic channel whose oscillating channel section is made of an anisotropic material oriented so that the modulus of elasticity governing stiffness perpendicular to the plane of oscillation exceeds that governing stiffness in the plane of oscillation). Claims 2–8 are dependent: claim 2 (silicon, specific crystal orientation — note the claim text as printed leaves the bracketed Miller indices blank), claim 3 (doped silicon), claim 4 (channel height > width), claim 5 (two parallel channels), claim 6 (U-shaped channel), claim 7 (inlet/outlet), claim 8 (measurement system for mass flow/density/viscosity). Because claim 1 carries a functional "wherein" clause about suppressing a disturbance mode / increasing sensitivity via the orientation of the material, invalidity and § 112 written-description/enablement attacks are plausible avenues worth scouting — but that is a prediction, not a PTAB finding.

Estoppel landscape. With zero petitioner and zero instituted trial, § 315(e)(2) estoppel is inapplicable — no person has been estopped. You may raise any prior-art ground you can support, including (a) the very references already in the file history, and (b) the pre-issuance art cited by the examiner, which is fair game if you can frame it better. Watch two practical constraints: (i) § 325(e)(1)/(e)(2) estoppel will bind you going forward once you file a petition, so plead your strongest grounds (and any § 112 grounds cannot be raised in an IPR at all — only in a PGR, which is time-barred here since the patent issued 2021-03-02, well beyond the 9-month PGR window); and (ii) the Fintiv-style discretionary-denial era has narrowed post-Commil/NHK-Fintiv USPTO practice, but a co-pending district-court case can still generate discretionary-denial risk that the patent owner will surely argue.

Pattern signals. No repeat petitioner, no defensive aggregator (no Unified Patents filing surfaced), and no PTAB appeal history for this patent. The patent is held by TrueDyne Sensors AG (a member of the Endress+Hauser group; E+H Flowtec appears on related family filings). Its family is small — US 10,935,404 B2, its US pre-grant pub US 2018/0348033 A1, EP 3368867 B1, CN 108351244 B, ES 2875754 T3, DE 10 2015 118 346 A1, WO 2017/071864 A1 — i.e., a targeted multi-jurisdiction filing, not a large portfolio being monetized through serial PTAB fights. That is consistent with a commercially practicing entity rather than a prolific litigant.

Recommended next steps

• No PTAB activity exists. State it plainly in any validity analysis: there is no FWD to cite, no canceled claim, and no estoppel. Anything suggesting otherwise (including the unrelated "'404" petition above) is a false match — verify the patent number AND the grant date (2021-03-02) before relying on any proceeding.
• Scout your own IPR. The window is open with no § 315(b) one-year bar triggered (no served complaint found). Institution requires your petition to show a reasonable likelihood that at least one of claims 1–8 is unpatentable, and the FWD is due within 12 months of institution (statutory deadline under 35 U.S.C. § 318(a)). Claim 1's functional material-orientation "wherein" clause is the natural target.
• Parallel foreign track. EP 3368867 B1 granted 2021-04-21; I found no EPO opposition data in the sources retrieved — but note the EPO opposition window (9 months from grant) has long closed (2022-01-21), so any European challenge would have had to be filed by then. If your exposure is European, verify the EPO register directly rather than inferring.
• Watch the family. TrueDyne/E+H continue filing (e.g., EP 3870947 B1, US 12,306,137 B2), and this sensor line is actively commercialized — so expect the patent owner to defend, not abandon, if asserted.

Limitations / confidence: I could not access the USPTO PTAB E2E docket or PTAB Decisions database directly in this session, and ODP (the canonical source in your prompt) reports zero proceedings. I therefore assert the absence with high confidence based on two independent checks, but I cannot prove a negative beyond the indexed sources. No proceeding numbers, panels, FWDs, or CAFC dockets are reported here because none exist to report — I have not invented any.

I'll research the assignment chain and ownership context. Let me run several targeted searches.

Let me dig into the specific assignment record and inventor/assignee details.

Assignment & Ownership Analysis — US 10,935,404 B2

Scope note / source limitation: I could not execute a live query against USPTO Assignment Center (the portal is JS-driven and my search tools returned no direct record pages). The reel/frame and event data below are taken from the assignment legal-events table embedded in the authoritative patent text provided (Google Patents, which mirrors the USPTO assignment database), cross-referenced against Swiss commercial-register and Endress+Hauser corporate sources. Anything I could not verify from a primary source is labelled unverified.

Inventors

Unusual-pattern check — no adverse finding. The rubric flags "all inventors departing the original assignee within 12 months of filing." The opposite is observed here: the inventors stayed inside the same corporate family (Huber's inventor profile shows a career arc across Endress+Hauser Flowtec AG and TrueDyne Sensors AG, both Reinach/CH). There is no evidence of inventor exodus preceding a portfolio sale. This is a corporate-startup R&D team, not a detaching inventor group.

Original assignee

TrueDyne Sensors AG (recorded on the assignment as "TRUEDYNE SENSORS AG, SWITZERLAND"). Address of record: Christoph-Merian-Ring 20, CH-4153 Reinach (BL), Switzerland. Swiss UID CHE-101.669.146. Managing Director Josua Ritter; headcount ~10–12.

• Product embodying the claims — yes. TrueDyne ships commercial MEMS vibronic density/viscosity modules built on exactly the claimed architecture (resonantly vibrating microchannel, anisotropic silicon, Coriolis/bending-vibration measurement): DLO-M2 (liquid density), VLO-M2 (viscosity, Ω-shaped microchannel), DGF-I1 (gas density), and the earlier "Nanomass Density" module. See https://www.ist-ag.com/en/density-viscosity-sensors and the Density Module fact sheet (microchannel 160 × 200 µm) at truedyne.com.
• Primary line of business: development and OEM sale of MEMS-based microsensor measurement modules (density, viscosity, concentration, flow) for process, oil & gas, energy, life-science and food & beverage applications.
• Current status — operating. TrueDyne is a wholly owned company of the Endress+Hauser Group ("Die TrueDyne Sensors AG ist ein Unternehmen der Endress+Hauser Gruppe"). It is actively trading and filing new patent applications as recently as 2025–2026 (e.g. US 12,596,058 B2, US 12,498,061 B2). It is not dissolved, not in bankruptcy, and not an IP-holding shell.
• Corporate-name wrinkle (flag): The Swiss register shows UID CHE-101.669.146 previously trading as Metso Endress+Hauser Technology AG (registered under that name 2004–2006, incorporation date 27 Dec 2000), while Endress+Hauser's own magazine and corporate pages describe TrueDyne as founded at the turn of 2014/2015. These are reconcilable only if the pre-existing entity was renamed/re-purposed into TrueDyne Sensors AG. This is a Swiss registry change-of-name event, not a US-recorded assignment — and no US change-of-name assignment appears in the '404 record. Sources: https://www.northdata.com/TrueDyne%20Sensors%20AG,%20Reinach/CHE-101.669.146 ; https://graph.swiss/en/companies/truedyne-sensors-ag/[669366](/patent/669366)

Assignment timeline

The Google Patents legal-events table for US 10,935,404 lists exactly one assignment event. There are no security agreements, no merger records, no post-issuance transfers, and no releases of record for this patent.

• 2018-02-14 (recorded effective date — execution date not separately shown in the source and is commonly identical) / recorded 2018-04-27 — Reel 045659/0888
  • Conveyance: Assignment — "ASSIGNMENT OF ASSIGNORS INTEREST" (USPTO event code AS)
  • Assignor: REITH, Patrick; HUBER, Christof; FETH, Hagen (all three named inventors)
  • Assignee: TRUEDYNE SENSORS AG, Switzerland
  • Correspondent: Not recoverable from the sources available to me — unverified. The legal-events table does not expose the correspondent/attorney of record for reel 045659/0888. This must be pulled directly from Assignment Center. For context only (not a substitute): the Endress+Hauser family's US prosecution correspondent is Endress+Hauser (USA) Holding, Inc. (see https://www.patentbots.com/patentverse/law-firm/EndressHauser-USA-Holding-Inc./), and the E+H group also uses internal Group Services entities — but I have no evidence any of these filed this particular recording.
  • Context: Original inventor-to-employer assignment (standard company ownership capture), executed during US national-phase entry of PCT/EP2016/071397 (US app. 15/771,938), roughly 18 months after the PCT filing and 3 years before grant. No consideration type is stated in the record.

Supporting signal on assignee character: the same-day legal event "ENTITY STATUS SET TO UNDISCOUNTED … LARGE ENTITY" (2018-04-27) means the applicant self-identified as a large entity — consistent with an Endress+Hauser group operating company, and inconsistent with a small single-purpose shell.

Flagged potential contradiction: The Dutch RVO Hoofdblad IE register (14 Jul 2021) lists (73) TrueDyne Sensors AG AND Endress+Hauser Flowtec AG for the EP family member of this German priority (102015118346). That points to co-ownership or a recorded licence at the EPO, which is NOT mirrored in the US assignment record. Either the co-ownership was not recorded at the USPTO or it applies only to other family members. Verify before treating "TrueDyne Sensors AG" as the sole US owner.

If no further records surface at Assignment Center, the plain reading is: TrueDyne Sensors AG remains the sole owner of record.

Timeline diagram

timeline
    title Ownership of US 10935404
    2015 : Priority filing in Germany
    2016 : PCT application filed
    2018 : Inventors assign to TrueDyne Sensors AG
         : US national phase published
    2021 : US patent granted
    2024 : Maintenance fee paid

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The only recorded conveyance (Reel 045659/0888, eff. 2018-02-14 / rec. 2018-04-27) runs from three individual inventors to an operating Swiss stock corporation with a physical HQ, a commercial product line, employees, and self-declared large-entity status. No "IP/Holdings/Ventures" suffix, no registered-agent address, no single-member Delaware/Texas LLC.

2. Known asserter in the chain — not present. Neither assignor nor assignee matches any public NPE list (Acacia, Marathon, IV, IPNav, Wi-LAN, Conversant, Vringo, Pendrell, Round Rock, Spangenberg entities, etc.). No Unified Patents or RPX high-frequency-plaintiff listing surfaced for TrueDyne Sensors AG or Endress+Hauser Flowtec AG.

3. Repeat correspondent across the chain — unclear / not assessable. There is only one link in the chain, so recurrence cannot be tested. I could not retrieve the correspondent for reel 045659/0888. Per the rubric, a single appearance is not a finding in any event.

4. Cascading transfers — not present. One recorded transfer; no chained LLCs, no shared correspondent addresses, no sub-24-month cascade.

5. Pre-litigation transfer — not present. There is no litigation naming this patent (see the litigation section of this analysis), and the sole assignment predates grant (2021-03-02) by ~3 years. Nothing was timed to a complaint.

6. Bankruptcy fire-sale — not present. TrueDyne and parent Endress+Hauser are solvent operating entities; no Chapter 7/11 or equivalent Swiss insolvency record surfaced.

7. Privateering — not present. The patent never left the Endress+Hauser corporate family; there is no transfer to a third-party NPE asserting on the operating company's behalf, and no SEC/EFF/Patent Progress coverage of such a scheme.

8. Defensive aggregator — not present. The chain terminates at an operating subsidiary, not at RPX, AST, LOT Network, Unified Patents, or OIN. (Inverse reading: the patent is not neutralised by a defensive aggregator; it is actively held in-house.)

Verdict

Insufficient data — under the task's own literal criterion for that bucket ("no records, or only the original assignment").

Justification: The only recorded assignment is the original inventor-to-employer conveyance to TrueDyne Sensors AG (Reel 045659/0888, effective 2018-02-14, recorded 2018-04-27), and there are zero post-issuance transfers, security interests, or name-change records on the US patent. Substantively this is not an NPE situation at all: the assignee is a solvent, product-shipping operating company owned by the Endress+Hauser Group, all eight NPE/troll-pattern signals are "not present" or "not assessable," and no assertion activity exists — so no NPE category fits, and the rubric supplies no dedicated "operating company, non-asserting" label.

Verification: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (query 10935404; also https://assignment.uspto.gov/patent/index.html). Pull reel 045659/0888 to capture the execution date and the correspondent of record, both of which are the two data points I could not confirm, and check whether any Endress+Hauser Flowtec AG co-ownership record exists for the US patent to resolve the EP-vs-US discrepancy flagged above.

I'll research the cited references for US 10,935,404, grounding each in authoritative sources.

Let me verify the remaining key references.

Let me verify the remaining structural references.

Scope and method

I worked from the authoritative full text you supplied (Google Patents rendering of US 10,935,404 B2) plus live web searches to confirm the cited references. Two things up front:

1. I could not run a direct USPTO Patent Center / USPTO full-text query for 10935404 — I have no USPTO API access here, only web search. The citation data below is taken verbatim from the patent's own "Citations / Patent Citations" lists in the supplied text, supplemented by searches that corroborated several references.
2. § 102 vs. § 103 framing. You asked which claim(s) each reference "potentially anticipates" under 35 U.S.C. § 102. I have answered that literally, but I must flag the honest result: no cited reference discloses all elements of claim 1, and because every one of claims 2–8 depends from claim 1, no cited reference anticipates any claim of this patent on its face. These are § 103 (obviousness) references, and I say so per-reference below rather than overstating § 102.

What claim 1 requires (the anticipation yardstick)

For any reference to anticipate, it must disclose, in a single reference: (a) a MEMS sensor for density/flow/viscosity of a fluid; (b) a microfluidic channel with a channel section excitable to oscillate; (c) an exciter effecting oscillations in a predetermined plane of oscillation; (d) the channel section composed of an anisotropic material with directionally dependent elasticity, oriented so that the modulus governing out-of-plane stiffness > the modulus governing in-plane stiffness; and (e) the stated suppression/sensitivity result. Element (d) — anisotropy spatially oriented relative to the oscillation plane — is the novel core and is what no reference supplies.

Patent citations — reference-by-reference

Dates below are the priority/publication dates as listed in the patent's citation tables (authoritative source = supplied Google Patents text).

Family-cited references (cited in the family, also citable as prior art)

The deficiency in the citation list worth flagging

US 2002/0194908 A1 appears in the patent's specification but NOT in its citation list. The specification names it twice — in the Background ("described, for example, in DE10,2008/039045 A1, US 2010/0037706 A1 and US 2002/0194908 A1") and in the Detailed Description (as the source of the pressure sensors used for the Hagen–Poiseuille viscosity measurement). The German sibling DE 10 2015 110 711 A1 (same family, retrieved via search) describes US 2002/0194908 A1 as disclosing "a central sensor region equipped with a measuring channel flowed through by the fluid in measurement operation, which has a channel section excitable to oscillate" plus integrated pressure sensors. That is a MEMS sensor with an oscillatable channel section — squarely relevant to claim 1(a)–(c) and to claim 8 (viscosity/pressure-drop measurement). Yet it does not appear among the 18 "Patent Citations" in the supplied text. I report this as a discrepancy in the citation data, not as an error in the patent: the Google Patents citation table is not the same as the examiner's IDS. ⚠️ I could not retrieve US 2002/0194908 A1's own text or exact publication date within my available steps, so I cannot certify its full disclosure; treat it as a probable § 103 reference with an unresolved § 102 question, not a confirmed one.

Also note: CN 1 353 809 A is cited (item 6), but its US equivalent US 6,314,820 B1 is not separately listed — a family redundancy, not an omission.

Non-patent literature

Bottom line

No cited reference anticipates any claim of US 10,935,404 under § 102. Every claim depends from claim 1, and claim 1's distinguishing element — a channel section composed of an anisotropic material spatially oriented so its out-of-plane modulus exceeds its in-plane modulus relative to the oscillation plane — appears in none of the 18 patent citations, the 3 family-cited references, or the NPL. The references instead map onto claim 1 as an obviousness combination:

• US 5,731,527 (anisotropic material in a Coriolis meter to separate vibrational modes) + CN 1 353 809 A / US 6,314,820 (stiffness-per-plane separation of a lateral disturbance mode) + a MEMS microfluidic micro-Coriolis reference (US 2010/0037706 A1; DE 10 2008 039 045 A1; US 6,647,778 B2) + Hopcroft et al. (silicon's anisotropic moduli) is the natural § 103 attack on claim 1.
• DE 10 2008 039 045 A1 is the strongest single § 103 reference against claim 5 (two parallel tubes, opposite-phase, in-plane drive).
• EP 1 158 289 B1 and US 2002/0194908 A1 bear on claim 8 (viscosity via damping / pressure drop).

Confidence

• Citation identities, dates, and titles: high — taken from the authoritative patent text.
• Technical descriptions of US 5,731,527, CN 1 353 809 A, DE 10 2008 039 045 A1, US 2010/0037706 A1: high — corroborated by live search.
• EP 0 547 455 A1 and US 2002/0194908 A1 content/dates: low — not retrieved; flagged as such.
• The "no anticipation" conclusion: high, subject to the caveat that I could not read every cited reference's full text, and to the general principle that a negative § 102 finding is a function of the references examined.

I'll ground the analysis in the specific prior-art references cited on this patent's face plus the NPL references, verifying their disclosures before reasoning.

Obviousness Analysis — U.S. Patent No. 10,935,404 B2 under 35 U.S.C. § 103

Analyst note on scope/method. I am analyzing obviousness using the prior art of record on the face of this patent (its "Citations," "Family Cites Families," and "Non-Patent Citations" lists) plus the references the specification itself identifies as background. Where I verified a reference's disclosure this session, I cite the source URL. Where I could not verify (I hit a tool-step limit on three queries), I say so explicitly rather than characterize the reference. This is an analyst's prima facie assessment, not a legal conclusion; obviousness is ultimately a legal question for a court, applying Graham v. John Deere, 383 U.S. 1 (1966), and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007).

Identifier discipline. I reproduce identifiers literally as they appear in the patent text. Note the specification renders the German Flowtec reference as "DE10,2008/039045 A1" and the viscosity reference as "EP01158289 B1"; the corresponding granted/publication numbers are DE 10 2008 039 045 A1 and EP 1 158 289 B1. I flag the rendering but do not silently relabel.

1. Framing the claim and the person of ordinary skill

Claim 1 is the only independent claim, and it defines a genus that is broader than the specification's disclosed embodiments:

PHOSITA (KSR ¶ 6): a mechanical/MEMS engineer with a degree in mechanical engineering, applied physics, or materials science and ~3–5 years' experience in micromachined sensor design, familiar with (i) Coriolis/vibration-type flow and density measurement, (ii) silicon micromachining (DRIE, wafer bonding, DRIE-etched U-profiles), and (iii) the directional elastic properties of single-crystal silicon.

Critical structural observation for § 103: because limitation (c) recites "an anisotropic material" without limiting it to the substrate material or to silicon, the fiber-reinforced composite of the closest art is within the claimed genus. And because the claimed device is micromachined, the channel walls will in nearly every practical case inherently be single-crystal silicon — itself an anisotropic material. This collapses the gap the Applicant relied on during prosecution.

2. The prior art of record — what each reference teaches

3. Ground 1 — The primary combination: US 5,731,527 + DE 10 2008 039 045 A1 (or US 2010/0037706 A1) + Hopcroft

This is the strongest § 103 position, and it tracks the KSR "known technique applied to a known device" rationale.

3.1 Chart for claim 1

3.2 Why the combination is proper (motivation, per MPEP 2143 / KSR)

1. Same field, same problem, same solution. US 5,731,527 identifies precisely the problem the '404 patent identifies — disturbance modes degrading accuracy — and solves it the same way: directionally tailoring the elastic modulus of a vibrating conduit to (a) separate the disturbance-mode eigenfrequency from the drive-mode eigenfrequency, and (b) raise Coriolis sensitivity. DE '045 / US '706 supply the MEMS microfluidic conduit and exciter.
2. KSR "known technique → known device." The technique of anisotropy-tailoring for mode separation was known in the same art (Coriolis meters); applying it to a miniaturized Coriolis channel is the paradigm KSR case: "if a technique has been used to improve one device, and a person of ordinary skill … would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond his or her skill."
3. Design incentive to miniaturize. DE '045 itself states the motivation — measuring "kleinster Massendurchflüsse" (smallest mass flows) in biotech/chemical/medical applications requires far smaller tubes. The '404 patent's own assignee lineage is the same (DE '045's "Cited By" list includes DE 10 2015 118 346 A1, the German priority of this very patent).
4. A finite, predictable set of solutions. For a (001) wafer, the designer's choices are to align the channel's longitudinal axis with <110> (E = 169 GPa) or <100> (E = 130 GPa). Choosing the orientation that puts the higher modulus in the disturbance direction and the lower modulus in the drive direction is a binary, predictable optimization — KSR's "finite number of identified, predictable solutions."
5. The Applicant's own IDS cited Hopcroft. The exact NPL that quantifies 169 vs 130 GPa was before the examiner. That is evidence the reference is analogous art and central to the claimed physics, and it undercuts any later argument that the modulus values were non-obvious.
6. The "transfer" problem the Applicant raised evaporates. The specification argues US 5,731,527 is "not directly transferable to MEMS sensors" because one would have to find a fiber composite that can be "applied externally on microfluidic channels" and bonded so it survives oscillation. But claim 1 does not require an externally applied composite; it requires the channel section be "composed of" an anisotropic material. In a device micromachined from a (001) silicon wafer (as DE '045/ US '706 teach), that limitation is met by the substrate itself — no added strip and no bonding step.

3.3 Ground 1 conclusion

A prima facie case of obviousness exists that claim 1 is unpatentable over US 5,731,527 in view of DE 10 2008 039 045 A1 (or US 2010/0037706 A1) and Hopcroft et al. The remaining question (§ 4 below) is whether the functional "wherein" clause supplies patentable weight.

4. Ground 2 — Alternative primary combination (microfluidic-resonator lineage)

US 2010/0037706 A1 (ISS) + US 5,731,527 / US 6,314,820 + Hopcroft.

US '706 is arguably an even closer structural match to claim 1 because it is a microchannel resonator with a defined in-plane vibration (it teaches vibrating the tube portions in the plane of the tube structure, 180° out of phase, to reduce clamping loss). Combined with the Micro Motion anisotropy teaching (US 5,731,527 / US 6,314,820) and Hopcroft's silicon moduli, the same limitation-by-limitation mapping applies. The motivation is even more direct: US '706 is expressly concerned with mechanical energy dissipation to the substrate and with mode behavior — the same family of concerns as the '404 patent's disturbance-mode suppression.

Ground 3 (secondary): US 2004/0038426 A1 / US 2005/0064581 A1 (Manalis) + US 5,731,527 + Hopcroft — suspended microchannel resonators establish the density/resonance principle in a micromachined channel; lateral alignment of the channel with the crystal axes follows Hopcroft.

5. Dependent claims 2–8

6. The functional "wherein" clause — does it save claim 1?

Claim 1's final clause recites a result (disturbance-mode suppression or increased sensitivity), not structure. Under settled practice (MPEP 2114; In re Schreiber), where a "wherein" clause states an inherent result of a structural limitation, it does not narrow the claim. Here:

• The structure is "E⊥ > E∥ for the channel section" (limitation (c)).
• The stated result is the physical consequence of that structure (higher out-of-plane frequency → separation from the in-plane drive mode; lower in-plane stiffness → greater Coriolis response).

So even setting aside US 5,731,527's express recitation of both results, the clause would be entitled to little or no patentable weight. This is the point flagged in the earlier summary and it remains the single most vulnerable feature of claim 1.

7. Patentee's expected rebuttals, and their likely force

8. Flags, contradictions, and uncertainties

(a) Miller indices in claim 2 — unresolved, and it matters for § 103. The granted claim text retrieved from Google Patents reads only "the direction of the crystal structure extends in parallel with the longitudinal axis … and … in parallel with a surface normal" — the (110)/(001) indices are blank/absent, whereas the specification ("[110] … [001]") and the EP/DE/WO family recite them. I am not silently inserting the indices. Consequence: as literally retrieved, claim 2 is broader, and therefore more obviously anticipated/met by any single-crystal channel in a (001) wafer with its axis aligned to a crystal direction — which strengthens, not weakens, the § 103 case. If instead the printed claim omits the indices while the specification requires them, there is also a potential § 112 written-description/enablement flag. Either way, the discrepancy should be resolved against the USPTO printed claim, which I could not access.

(b) Technical premise of the directional-modulus distinction — flagged, not resolved. The specification asserts that for a channel whose axis is [110] with the oscillation plane in (001), the [110] modulus (169 GPa) governs perpendicular deflection and the [100] modulus (130 GPa) governs in-plane deflection. For a uniform closed-section beam, simple Euler–Bernoulli analysis would invoke the same longitudinal modulus (E₁₁₀) for both bending directions; the claimed difference more plausibly arises from thin-wall/plate or local wall-bending effects that the specification does not develop. I flag this as an unresolved technical point affecting how claim 1 reads on a given silicon orientation (and potentially § 112 / inoperability), but it is outside the § 103 core — and note that on either reading it cuts against patentability: if the property is real it is a known material property (Hopcroft); if it is not, the claim's structural limitation may lack a supporting mechanism.

(c) Prior-art ladder not fully verified. I could not retrieve the content of US 2002/0017132 A1 ("Micro-machining," Secretary of State for Defence), DE 699 36590 T2 (Qinetiq), CN 102037644 A / US 8,680,951 B2 (NXP), US 2010/0242606 A1 (Seiko Epson), CN 103293338 A, or the German and PCT search reports (NPL) — my session hit a tool-step limit. I have built no essential element on these. The German search report (13.07.2016) and PCT ISR (14.12.2016) would very likely categorize the closest art and are the recommended next documents to obtain.

(d) Internal consistency flag (carried from earlier sections). Claim 1 introduces "an exciter"; claims 5–6 and 8 refer to "the exciter system." Also, the "List of Reference Characters" in the specification is internally corrupted (e.g., "5 support / 5 channel section; 9 channel walls … 11 inlet"), so reference-numeral mappings from the spec should be treated cautiously.

9. Overall conclusion

• Claim 1 is prima facie obvious under § 103 over US 5,731,527 A1 in view of DE 10 2008 039 045 A1 (and/or US 2010/0037706 A1) and Hopcroft et al. The Micro Motion reference supplies the identical anisotropic-material/mode-separation/sensitivity solution to the identical problem in the same field; the Flowtec and ISS references supply the MEMS microfluidic channel, the exciter, and the predetermined plane of oscillation; Hopcroft supplies the specific, quantified anisotropy of the substrate material. KSR's "known technique applied to a known device," "finite number of predictable solutions," and "design incentive/known physical property" rationales all apply.
• Claims 2–8 fall with claim 1 on the same or additional combinations (notably DE 10 2008 039 045 A1 for the two-parallel-channel (5) and U-shaped/opposite-phase (6) variants, and US 2010/0037706 A1 / EP 1 158 289 B1 for the measurement-system limitations of claim 8).
• The strongest patentability foothold, if any, is not in claim 1's structure but in the possibility that the printed claim 2 carries narrowly specific crystallographic indices; even that foothold is weak because Hopcroft tells the designer exactly which orientation to use on a standard (001) wafer.
• Recommended next steps to firm up or defeat this analysis: (i) obtain the USPTO printed claims to confirm or refute flag (a); (ii) obtain the German and PCT search reports (flag (c)); (iii) obtain the 2020 non-final office action and the Applicant's remarks, to see precisely how the examiner distinguished US 5,731,527 — because that distinction, if it rests on the "not transferable to MEMS" argument, is the argument most exposed under KSR.

Confidence: claim-element mapping to the primary references and Hopcroft: high (verified this session). The § 103 conclusion: moderate-to-high as a prima facie matter, subject to the § 112/printed-claim uncertainties in flags (a) and (b), and to any secondary-considerations evidence that may exist but is not of record in the materials I have.