US 11346778

I'll check the specified sources for this exact patent number before summarizing.

US 11,346,778 B1 — Verified Summary

Verification note: I searched for the exact number 11346778. Authoritative bibliographic data was confirmed on Espacenet, Google Patents, and Justia. A separate search targeting "CAFC 2026 docket" returned no judicial or PTAB activity for this patent — the numeric matches that appeared (11346778 in a Rio Grande do Sul, Brazil corporate registry listing and in a UK Gazette dissolution notice) are unrelated legal-entity registration numbers, not this patent. I did not auto-correct or merge any of those. I have no authoritative confirmation of any litigation, so treat "no known litigation" as absence of evidence, not evidence of absence.

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Bibliographic data

Sources: Google Patents, Espacenet bibliographic, Espacenet claims, Justia.

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Abstract (as issued)

The present invention provides a method for detecting petroleum with a staggered toroidal chip, comprising the following steps: step 1, dry the test environment of a terahertz spectrum analysis system, measure a spectrum under dry conditions, and use the spectrum as a reference spectrum; step 2, use a pipette to transfer a crude oil sample and evenly smear it on the metasurface of a staggered toroidal chip; step 3, put the staggered toroidal chip coated with the crude oil sample into the dried terahertz spectrum analysis system, let a terahertz pulse signal of the terahertz spectrum analysis system to be vertically irradiated on the chip for detection, and then get a detection spectrum of the crude oil sample; step 4, subtract the reference spectrum from the detection spectrum, and then get a transmission spectrum of the crude oil sample, wherein the staggered toroidal chip is a terahertz chip designed based on the dual-torus toroidal effect.

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Independent claim 1 — plain-language overview

This is a method claim (a measurement/detection workflow), not an apparatus claim. In ordinary terms:

1. Dehumidify the instrument and take a background reading. Dry the test environment of a terahertz (THz) spectroscopy system and record the spectrum in the dry condition as the reference spectrum.
2. Load the sample. Use a pipette to deposit a crude-oil sample and smear it evenly across the metasurface of a "staggered toroidal chip."
3. Transmit-measure. Place the oil-coated chip in the dried system; irradiate it vertically with the THz pulse and collect a detection spectrum.
4. Normalize. Subtract the reference spectrum from the detection spectrum to obtain the sample's transmission spectrum.

The single point of novelty is the final wherein-clause: the chip must be a THz chip "designed based on the dual-torus toroidal effect." Everything else in claim 1 is conventional THz-TDS practice (dry purge → pipette-load → normal-incidence transmission → reference subtraction). The chip's internal geometry specified in claim 2 is not a limitation of claim 1, so claim 1 is comparatively broad.

The specification motivates this over the prior art as follows: Fano-resonance metamaterial sensors are "distorted… caused by the asymmetry of the Fano oscillation," and "the Fano oscillation itself is unstable with the long detection time," whereas the dual-torus toroidal response is claimed to be more stable — a higher-Q, environment-sensitive, "higher sensitivity and stability" sensor component.

Dependent claims (brief)

• Claim 2 — Defines the chip's geometry: a staggered structure of two circular split-ring resonators (CSRRs) that overlap; one CSRR center sits left of the chip's symmetry axis (OO′) with its gap to the right of that center; the mirror-image CSRR center sits right of OO′ with its gap to the left.
• Claim 3 — Dimensions: inner radius 35 μm, outer radius 40 μm, gap 4 μm.
• Claim 4 — Instrument: the system is the Advantest 7400, operated in transmission mode.
• Claim 5 — Sample parameters: crude-oil volume 1 μL–10 μL, smeared thickness 1 μm–3 μm.
• Claim 6 — Narrowed from claim 5: 2 μL and 1 μm.

Worked example (Embodiment 2): four crude oils of different origin gave distinguishable toroidal oscillations at resonance frequencies of 0.9384 THz, 0.9327 THz, 0.9136 THz, and 0.9594 THz; a fresh chip was used for each sample. Field distributions are reported near 0.546 THz. Advantest 7400 resolution is stated as 2.1 GHz.

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Procedural and drafting observations (factual, from the record)

• Cited prior art (11 refs) includes CN 105445219 A and CN 109580535 A (both University of Shanghai for Science and Technology), plus terahertz metamaterial sensors from Chongqing University of Posts and Telecommunications (CN 108414473 A, CN 109557050 A) and crude-oil-in-rock THz-TDS work from China University of Petroleum–Beijing (CN 104215603 A). Two non-patent citations: Liang Li et al., Infrared and Laser Engineering, vol. 48, no. 2 (Feb. 28, 2019), and the CNIPA ISR/WO dated Sep. 27, 2020.
• Forward citations listed: ZA 202202826 B (African New Energies Ltd, "Fano based crab sensor…") and US 12,546,637 B2 (Saudi Arabian Oil Company).
• CN 111141687 B ("Method for detecting petroleum by staggered structure ring dipole chip") appears on the page under "Similar Documents" — I am flagging that I cannot confirm from this record whether it is the Chinese family member of this PCT or merely a related-but-separate filing, so I am not asserting family status.
• Drafting inconsistencies preserved as-is: the specification contains the phrase "An embodiment of the present utility model" (utility-model language in a US utility patent — consistent with Chinese-origin drafting), and a truncation defect on the summary page reading "the thickness of the crude oil sample smeared on the staggered toroidal chip is 1 μm˜μm" (the corrected value is 1 μm–3 μm, per claim 5 and the detailed description). The abstract renders "measure a spectrum" on Google Patents and "measure the spectrum" on Justia; these are the same text as best I can tell.

Uncertainty disclosure

I could not query USPTO PatentCenter, PACER, or the Federal Circuit docket directly with the tools available; the "no CAFC activity" statement rests on web search only. If a definitive litigation/PTAB check is required, run the patent number in PatentCenter and Docket Navigator/PACER directly.

I'll research litigation involving US Patent 11346778.

Let me check litigation-specific databases.

Let me check dedicated litigation databases and docket sources.

Litigation Search Results — U.S. Patent No. 11,346,778

No litigation involving U.S. Patent No. 11,346,778 was found. I identified no district court complaints, declaratory judgment actions, ITC investigations, PTAB proceedings (IPR/PGR/CBM), or Federal Circuit appeals naming this patent.

What I checked

• General web searches for the patent number in litigation contexts
• Searches pairing the number with "lawsuit," "defendants," "docket," "case"
• Searches keyed to the patent owner and technology (University of Shanghai for Science and Technology; terahertz / toroidal dipole / crude oil detection)
• Searches for the patent's claim title language ("staggered toroidal chip")

The only hits returned were the patent's own prosecution/publication records (Google Patents, Espacenet, PatentLeaderboard), a related scholarly article in Infrared and Laser Engineering (Wu Yiping et al., "Terahertz dual torus toroidal sensing chip and its application in crude oil detection," 2022, 51(6): 20210338, DOI 10.3788/IRLA20210338), and unrelated documents.

⚠️ Important caution — do not conflate the following similarly numbered patents

These surfaced in my searches and are different patents with actual litigation activity:

None of these is the patent you asked about.

Why the absence of litigation is plausible

The patent is owned by the University of Shanghai for Science and Technology (Chinese assignee), with inventors Chen Lin, Yiming Zhu, Zhengji Ni, and Songlin Zhuang. Its claims cover a laboratory method of smearing a 1–10 µL crude oil sample on a terahertz metasurface chip and performing THz-TDS transmission detection. Several factors reduce litigation likelihood:

1. Method claims only — all six claims are process claims; there is no apparatus or composition claim covering a chip as a product, making infringement detection and proof of a commercially motivated suit harder.
2. Foreign university ownership — no U.S. commercialization or licensing entity appears to hold enforcement rights.
3. Narrow, research-scale field of use — the claims recite specific numerical parameters (inner radius 35 µm, outer radius 40 µm, 4 µm gap) and a specific instrument (Advantest 7400).
4. Companion Chinese family member — CN111687B is listed as "Method for detecting petroleum by staggered structure ring dipole chip," but that is a Chinese patent, not U.S. litigation.

Confidence and limitations

I am reporting a negative finding, which is inherently harder to verify than a positive one. My sources were general and specialized web searches, not direct PACER, Docket Navigator, Lexis, Westlaw, or Docket Alarm subscription queries, and I reached my search-step limit before completing a verification pass against the Unified Patents litigation portal or CourtListener/RECAP dockets. A definitive clearance opinion should include:

• A PACER docket search (all district courts) on "University of Shanghai for Science and Technology" as plaintiff
• A Docket Navigator / Lexis Patent Litigation query on 11,346,778
• PTAB Patent Trial & Appeal Board API / P-TACTS search on the patent number
• A USPTO Assignment search for any recorded security interests, licenses, or ownership transfers that might signal enforcement activity

Bottom line: Based on the searches performed, there is no known U.S. litigation involving U.S. Patent No. 11,346,778 as of April 26, 2026. I did not find any plaintiff, defendant, jurisdiction, case number, filing date, or outcome to report, because no case appears to exist.

I'll verify the "no proceedings" baseline with targeted searches before writing up the report.

Let me run a few more targeted checks — pet owner's litigation history, any Unified Patents challenge, and the CN family member.

Two final diligence checks — any IPR docket number referencing this patent, and any Chinese invalidation (CNIPA) on the family member.

PTAB / AIA Trial Proceedings — US 11,346,778 B1

Verification basis: the structured ODP block in this prompt (canonical source) reports no AIA trial proceedings on file. That was the starting point, and I attempted to falsify it with targeted web searches for (a) IPRs naming this patent or application no. 17/271,570, (b) petitions by/against University of Shanghai for Science and Technology on THz patents, (c) Unified Patents or other defensive aggregators active in the THz-metamaterial space, and (d) CNIPA invalidation of the Chinese family member. Nothing surfaced. Searches returned only the patent's own bibliographic pages, unrelated PTAB petitions on other patents, and — as the prior section already flagged — unrelated Brazilian corporate-registry numbers containing the digit string "11346778." Note the search tool was exhausted before two final confirmatory queries could run, so this is a high-confidence but not exhaustively exhaustive negative.

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Proceedings overview

Total AIA trial proceedings: 0. There is nothing to break down — no instituted trials, no final written decisions, no settlements, no institution denials, no pending petitions. No claim of US 11,346,778 has ever been tested, canceled, or sustained at the Board. The defensive posture this yields is not "hardened patent" and not "dead patent" — it is the third state, which practitioners routinely misread: an untested patent whose every claim (1–6) remains live and presumptively valid, but which carries zero § 315(e) estoppel against anyone and whose validity has never been scrubbed by an adverse panel. A defendant here gets a clean sheet: no estoppel burden, no adverse claim-construction record, no FWD to distinguish. It also gets no free win.

Because there are no proceedings, the per-proceeding template below is reported as empty rather than populated.

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No proceedings to report

I will not manufacture proceeding numbers. As of the most recent ODP ingest and the searches described above, the per-proceeding fields would all be vacuous:

• Type / Filed / Status / Panel / Grounds / Institution / FWD / Settlement / Appeal — not applicable; no trial exists.

Google Patents' litigation and PTAB sections for this patent are blank. Forward citations (ZA 202202826 B, "Fano based crab sensor," African New Energies Ltd; US 12,546,637 B2, Saudi Arabian Oil Co.) are third-party patents citing this one — citations, not challenges, and neither is a PTAB filing.

One genuine cross-reference resolved: the prior section flagged uncertainty over whether CN 111141687 B ("Method for detecting petroleum by staggered structure ring dipole chip") is the Chinese family member of PCT/CN2020/070089 or a separate filing. My search surfaced that CN 111141687 A was filed 2020-01-02 by 上海理工大学 (University of Shanghai for Science and Technology), published 2020-05-12, and granted as CN 111141687 B on 2022-10-14 — same assignee, same filing date, matching subject matter. That is consistent with a parallel Chinese domestic filing of the same invention, i.e., family-related, not a separate third-party patent. I could not confirm any CNIPA invalidation (无效宣告) or reexamination against it; treat that as unknown, not as "none exists." CNIPA invalidation would be the closest foreign analogue to a PTAB trial and would be worth a dedicated Chinese-register check.

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Strategic summary

Claim status: all six claims UNTESTED. Nothing is canceled, nothing is sustained. Claims 1–6 stand exactly as issued on 2022-05-31, with statutory expiry tracked to 2040-01-03 (adjusting for the PCT-delay adjustment) and the 4th-year maintenance fee paid 2025-11-04 as a small entity. For a defendant, this means the full issued claim set — including broad claim 1 and the narrower geometry claim 2 (overlapping staggered CSRRs, inner radius 35 μm / outer radius 40 μm / 4 μm gap) — is available to the patent owner as an assertion target. The patent has also never been construed by any tribunal, so there is no Phillips or Phillips-style record narrowing "designed based on the dual-torus toroidal effect."

Estoppel landscape: clean. Section 315(e)(2) estoppel attaches only to a petitioner (and its real parties in interest or privies) that obtained an instituted IPR and reached a final written decision. With no petitioner, no estoppel runs against anyone. Every § 102 and § 103 ground is fully available, including grounds that would normally be "reasonably could have raised" foreclosures. The countervailing exposure is § 325(d): the 11 references of record were before the examiner (Rosemount US 2004/0233458; JP 2013-064646; CN 102621083 A; US 2015/0090881; CN 104215603 A; CN 105445219 A; CN 108414473 A; CN 108627466 A; CN 109557050 A; CN 109580535 A; CN 109580443 A) plus two NPL items (Liang Li et al., Infrared and Laser Engineering 48(2), 2019-02-28; the CNIPA ISR/WO dated 2020-09-27). Re-running those references in the same or substantially the same way invites discretionary denial; the productive path is new art or a materially new theory of combination.

Pattern signals: none of the usual triggers. No repeat petitioner, no patent-owner appeal history (there is no FWD to appeal), no Unified Patents or aggregator involvement identified, and — critically — no evidence of any district court assertion of this patent. That last fact is almost certainly the reason for the empty docket: IPRs are filed as litigation-defense tools, and a method claim directed at "smearing crude oil on a THz chip and doing transmission spectroscopy" has an inherently narrow set of plausible infringers (oilfield-services labs, petroleum testing outfits, instrument users). A patent owner with no litigation campaign generates no IPR traffic regardless of how weak its claims might be. The absence of PTAB activity here is not evidence of patent strength — it is evidence of low assertion volume.

Remedial channel caveat — this matters. IPR is limited to grounds under § 102 and § 103 (and, in the joined-petition context, § 112 only via motion to amend). The obvious attack surface on claim 1 — that "a terahertz chip designed based on the dual-torus toroidal effect" is a result-oriented, functional characterization arguably indefinite under § 112(b) and unsupported as a genus under § 112(a) — is not available in an IPR. It was available only in a PGR, whose § 321(c) nine-month window closed on 2023-02-28. CBM is unavailable: the AIA § 18 transitional program sunset on 2020-09-16 and this patent does not cover a financial product or service. IPR is now the only AIA vehicle — and it cannot reach the patent's weakest flank. § 112 must be litigated in district court or raised as an affirmative defense.

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Recommended next steps

If you are a defendant being asserted against:

• There is no FWD to cite. Do not build an invalidity narrative on PTAB outcomes, because none exist. Whatever validity defense you have must be built from scratch on the art.
• Check your § 315(b) clock immediately. One year from service of the complaint. There is no proceeding on file, so no petition exists to piggyback on and no bar has yet been triggered by anyone else. With no litigation of record, there is no existing bar at all.
• Commission a fresh prior-art search rather than recycling the record. The high-value art families to sweep — all pre-dating the 2020-01-02 effective filing date — are: (i) toroidal-dipole / toroidal-metamaterial metasurface literature (the KAIST / Fedotov / Papasimakis / Zheludev toroidal-response line of work), (ii) THz split-ring-resonator and asymmetric-double-SRR sensors, and (iii) THz-TDS petroleum and crude-oil characterization (the China University of Petroleum–Beijing CN 104215603 A line). I am not asserting that any specific reference discloses claim 1's wherein-clause — that requires a verified search — but these are the correct starting coordinates.
• Mind the grace-period date trap. Effective filing date is 2020-01-02. Any public disclosure by the USST inventors between 2019-01-02 and 2020-01-02 is a candidate for the § 102(b)(1)(A) grace-period exception and must be cleared before you rely on it. Disclosures before 2019-01-02 are fair game as § 102(a)(1) art. Given that this is an academic group with an active publication record, the pre-2019 USST literature is worth targeted review.
• Run § 102(a)(2) against the same-day parallel filing. CN 111141687 A (filed 2020-01-02) is not § 102(a)(2) art against its own family member, but any other same-day or intervening filing by third parties is worth checking for § 102(a)(2) exposure.
• Preserve the § 112 attack for court. Indefiniteness of "designed based on the dual-torus toroidal effect," plus enablement/possession of the chip genus given that FIG. 2 is simulated field data and the worked example spans only four oil samples with no manufacturing disclosure for the chip, is your best non-IPR lever.

Milestone tracking — not applicable. There is no institution decision deadline, no oral hearing, and no statutory 1-year FWD date to monitor, because no trial has been instituted.

If you simply need the negative confirmed on the record: re-run the patent against USPTO PTAB E2E (https://ptacts.uspto.gov/ptabweb/) and the PTAB API/ODP directly, and — if the CN family matters to your matter — pull the CNIPA register for CN 111141687 B to test for invalidation, since that is the one avenue I could not close out with the tools available.

Bottom line: no PTAB proceedings exist on US 11,346,778 B1. No claim is canceled, no claim is sustained, and no estoppel binds anyone. The defensive value of the PTAB record to a defendant is exactly zero — which cuts both ways.

I'll verify the assignment record and check for any assertion/NPE activity before writing up.

Ownership & Assignment Reconstruction — US 11,346,778 B1

Scope note: I could not open the USPTO Assignment Center UI directly with the tools available (assignmentcenter.uspto.gov is a JS-driven search app; the equivalent indexed record is what Google Patents surfaces in its "Legal Events" tab, which mirrors the Assignment Center's reel/frame data). The reel/frame data below is taken from the patent's own Legal Events record (Google Patents) and matches the bibliographic data on Espacenet. Where a field is only exposed in the Assignment Center UI and not in the mirrored record — specifically the Correspondent of record — I say so rather than guess.

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Inventors

Patterns / flags:

• No inventor departure signal. All four inventors appear as assignors on the 2021 assignment to USST, i.e., they transferred to the original assignee rather than away from it. There is no record of any inventor assigning to a third party.
• This is a Chinese-university-origin PCT national-stage case, so the "inventors assigned after filing" pattern is expected, not suspicious: PCT/CN2020/070089 was filed 2020-01-02 with USST as applicant, and the inventors' confirmatory assignment was executed 2021-02-19 — contemporaneous with US national-stage entry (US 17/271,570), roughly 13 months after the PCT filing. I flag it only because for diligence purposes it means the inventors' rights were perfected on the US national-stage timeline, not at the PCT filing date.
• Employer attribution is inferred from co-inventor overlap across USST's cited portfolio, not confirmed from an employment record. Treat as high-confidence but not documentary.

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Original assignee

University of Shanghai for Science and Technology (USST) — Shanghai, CN.

• Entity named on the issued patent: USST (original and current assignee per Google Patents and Espacenet).
• Primary line of business: Public research university (education + sponsored research). It is not a commercial manufacturer.
• Product embodying the claims: No commercial product identified. The claimed subject matter is a laboratory measurement method (dry-purge → pipette-load crude oil on a staggered dual-torus toroidal metasurface → normal-incidence THz-TDS transmission → reference subtraction) executed on an Advantest 7400 commercial spectrometer. The chip is a research-grade metasurface fabricated by the group (1 cm × 1 cm, CSRR inner radius 35 μm / outer radius 40 μm / 4 μm gap). USST's "product" here is published research and the resulting patent family (WO 2021134749 A1; US 20220146419 A1), not a shipped article of commerce.
• Current status: Operating (public university). No bankruptcy, dissolution, or acquisition found. Entity status was set to small entity on 2021-08-13 (reel-level entity-status event), and the 4th-year maintenance fee was paid 2025-11-04 (maintenance-fee event, small entity) — i.e., the patent is being actively maintained by the university.

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Assignment timeline

Chronological list of recorded conveyances. There is exactly one recorded assignment, and it is the original inventor→assignee transfer. There are no post-issuance transfers, no security interests, no licenses recorded, and no change of name.

• 2021-02-19 (executed) / recorded 2021-02-25 — Reel 055418 / Frame 0043
  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignor: CHEN, LIN; ZHU, YIMING; NI, ZHENGJI; AND OTHERS (the "and others" is the fourth inventor, Songlin Zhuang, per the inventor list)
  • Assignee: UNIVERSITY OF SHANGHAI FOR SCIENCE AND TECHNOLOGY (Shanghai, CN)
  • Correspondent: Not retrievable from the mirrored record. Google Patents' Legal Events only exposes the reel/frame plus the free-format text "ASSIGNMENT OF ASSIGNORS INTEREST; ASSIGNORS: CHEN, LIN; ZHU, YIMING; NI, ZHENGJI; AND OTHERS; REEL/FRAME: 055418/0043." The Correspondent field (attorney/agent who filed the recording) is only displayed in the Assignment Center detail view for reel 055418 frame 0043 and I could not open it. Because this is the only link in the chain, recurrence testing is impossible anyway — a single appearance by a firm is explicitly not a finding under your own rule. (Superseding note: the "055418" hits returned by open-web search are a PCT/DK wind-turbine publication number and an unrelated PCT/US2009/055418 search report — do not conflate them with this reel.)
  • Context: Confirmation/perfecting assignment on US national-stage entry — the four inventors' rights in the PCT (filed by USST as applicant) were formally assigned to USST in Feb 2021, matching the US 17/271,570 national-stage entry. Not an acquisition, not a fire-sale, not a securitization.

Related but not an assignment (for completeness):

• Entity-status / fee events 2021-08-13 (small entity) and the 2025-11-04 4th-year maintenance-fee payment are Fee Payment Procedure and Maintenance Fee Payment entries, not conveyances. They appear in the same Legal Events feed and should not be mistaken for ownership changes.
• Family: WO 2021134749 A1 (WO status per Google Patents: not_active / ceased — the normal consequence of US national-stage entry); US 20220146419 A1 (pre-grant publication). Family ID 76685889.

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Timeline diagram

timeline
    title Ownership of US 11346778
    2020 : PCT filed by USST
         : PCT CN2020070089
    2021 : Inventors assign to USST
         : Executed 2021-02-19
         : Recorded 2021-02-25 reel 055418
    2022 : US patent issued 2022-05-31
    2025 : 4th year maintenance fee paid

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NPE / troll-pattern signals

Forward-looking risk note (not a present signal): Chinese public universities are a recognized source pool for later monetization — the typical future vector is an assignment to a tech-transfer intermediary or a foreign licensing vehicle. Nothing in this record shows that has happened; the only forward citations of record are ZA 202202826 B and US 12,546,637 B2, both third-party irrelevant to title.

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Verdict

Insufficient data — more precisely: no NPE pattern present, chain contains only the original assignment.

Justification: the entire recorded chain is a single conveyance — inventors Chen, Zhu, Ni and Zhuang to University of Shanghai for Science and Technology, executed 2021-02-19 and recorded 2021-02-25 at reel 055418, frame 0043 — which is the standard confirmatory assignment accompanying US national-stage entry of PCT/CN2020/070089. No shell entity, no known asserter, no cascading LLC transfers, no pre-suit transfer, no bankruptcy sale, and no defensive aggregator appear; the university is still the record owner and paid the 4th-year maintenance fee on 2025-11-04. The one genuine gap is the correspondent of record on reel 055418/0043, which the mirrored data does not expose and which would need to be pulled from the Assignment Center detail view.

Verify at: USPTO Assignment Center — search 11346778 or reel 055418 frame 0043; mirrored bibliographic/legal-event record at patents.google.com/patent/US11346778B1/en.

Two limitations to carry forward: (a) I could not query PACER/Docket Navigator or the Assignment Center detail pages directly, so "no litigation" and the missing correspondent are absences of retrieved evidence, not proof; (b) the "AND OTHERS" wording in the assignment's free-format text is transcription shorthand for Songlin Zhuang — I am matching it to the four-inventor list rather than treating it as a fifth, unidentified assignor.

I'll verify the patent and each cited reference against live sources before analyzing anticipation.

Now let me verify the remaining cited references.

Prior-Art Analysis — US 11,346,778 B1

Note on dates: The task header states "Current Date: April 26, 2026"; the session's system date is 2026-09-29. I have used the later date, because a live record dated 2026-07-03 (an ownership transfer of cited reference CN 105445219 B, discussed below) falls between the two. This does not affect the §102 analysis, which is governed by the 2020-01-02 effective filing date.

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1. Number verification (literal, no auto-correction)

A search for the exact string 11346778 returns the patent identified in the previously generated section — the match is exact, not a near-number.

Sources: Google Patents, Justia, Espacenet claims.

No results for adjacent numbers (e.g., 11,346,777 / 11,346,779) were merged into this analysis.

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2. Legal framework applied

• Effective filing / priority date: 2020-01-02. Every one of the 11 cited references published before that date, so each is available as prior art under 35 U.S.C. § 102(a)(1) (printed publication) and, for the two US publications, also under § 102(a)(2) as of their earlier priority dates. There is no § 102(b) grace-period issue.
• Anticipation standard: a single reference must disclose every limitation of the claim, arranged as in the claim. Because claims 2–6 all depend from claim 1 (directly or via claim 2/5), any reference that does not anticipate claim 1 cannot anticipate claims 2–6. That single fact collapses most of this table.
• I have applied the claim limitations as the following shorthand elements:

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3. The 11 patent citations (as listed on the record)

Citation-mark convention on the Google Patents table is "* Cited by examiner, † Cited by third party." Four of the eleven carry the examiner marker: US 2004/0233458 A1, CN 104215603 A, US 2015/0090881 A1, CN 105445219 A. The remaining seven appear without an examiner marker. I have not re-characterized any of them beyond what the record shows.

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4. Reference-by-reference analysis

4.1 US 2004/0233458 A1 — Electromagnetic resonant sensor

• Assignee / dates: Rosemount, Inc.; priority 2000-11-28, published 2004-11-25. Examiner-cited. Family includes WO 2005/104348 A3 and granted US 7,330,271 B2 (2008-02-12).
• Disclosure: A dielectric sensor body that propagates electromagnetic wave energy; a cavity whose facing surfaces define a gap that varies with the measured parameter; the resonant frequency of the standing wave shifts with gap dimension. Application-level (pressure, temperature, flow) RF/microwave sensing; the disclosure also canvasses ring resonators, microsphere resonators, microdisc/VCSEL structures, photonic-crystal arrays and high-Q dielectric resonators.
• § 102 mapping: Touches only the abstract notion of a gap-defined resonator. Does not disclose E1, E2, E3, E4, E5, or any of C2–C6. Different frequency regime (RF/microwave), different measurand (physical process parameters), no petroleum, no THz-TDS, no toroidal dipole.
• Verdict: Anticipates no claim. Background art on resonant sensing; at most §103 art for "resonant sensor" generally.

4.2 CN 102621083 A — Method and system for measuring rock optical parameters based on terahertz time-domain spectroscopy

• Assignee / dates: China University of Petroleum (Beijing); filed 2012-03-08, published 2012-08-01.
• Disclosure: Measure the rock substrate and the rock sample by transmission THz-TDS; FFT the two time-domain waveforms; derive refractive index n(ν), extinction coefficient k(ν) and absorption coefficient α(ν); build the absorption and refractive-index spectra over the valid band. Sample is dried beforehand (50 °C, 48 h); thickness 0.02–0.05 mm.
• § 102 mapping: Element-level overlap with E1 (a substrate/reference waveform is taken before the sample measurement) and with the general form of E3/E4 (THz-TDS transmission through a sample, then spectral computation). Missing: crude oil (E2), pipette, metasurface/toroidal chip, subtraction to a transmission spectrum of an oil sample (E4 as claimed), and E5 entirely.
• Verdict: Anticipates no claim. Relevant to the generic THz-TDS reference-measurement and spectral-processing elements.

4.3 JP 2013064646 A — Method for evaluating material by terahertz spectroscopy

• Assignee / dates: National Institute of Information and Communications Technology; filed 2011-09-16, published 2013-04-11.
• Disclosure: Generic material evaluation by terahertz spectroscopy. Caveat: I retrieved only the record's title/assignee/dates for this reference; I did not obtain the Japanese full text, so the description is limited to that record.
• § 102 mapping: No petroleum, no chip, no metasurface, no toroidal effect. Cannot supply E2 or E5.
• Verdict: Anticipates no claim.

4.4 CN 104215603 A — Method for detecting crude oil content in rock pore by using terahertz time-domain spectroscopy technology

• Assignee / dates: China University of Petroleum (Beijing); filed 2014-09-10, published 2014-12-17; national-phase record shows the application was rejected after publication (驳回, 2018-02-09). Examiner-cited.
• Disclosure (claims 1–2): Prepare crude-oil/CCl₄ standard solutions at several volume ratios → THz-TDS measure each and record the time-domain peak → least-squares fit a volume-ratio/peak standard curve → soak the rock sample in a fixed volume of CCl₄ → measure the sample solution → compare its peak to the curve → derive the crude-oil content. The crude oil and the rock's oil are to come from the same block.
• § 102 mapping: This is the closest subject-matter match in the set (crude oil + THz-TDS). But it (i) detects oil in rock pores via solvent extraction, not neat oil smeared on a chip; (ii) normalizes with a fitted standard curve, not by subtracting a reference spectrum (E4 as claimed); (iii) has no metasurface, no split-ring geometry, no pipette transfer of neat oil, and no toroidal/dual-torus effect (E2, E5, C2, C3, C5, C6 all absent).
• Verdict: Anticipates no claim. Strongest §103 candidate for "detect petroleum with THz-TDS," but it contributes nothing toward the chip limitations that carry the claim.

4.5 US 2015/0090881 A1 — Methods, sampling device and apparatus for terahertz imaging and spectroscopy of coated beads, particles and/or microparticles

• Inventor / dates: Edward E. King; priority 2013-09-30, published 2015-04-02. Examiner-cited.
• Disclosure: A sampling device and apparatus for THz imaging/spectroscopy of coated beads, particles and/or microparticles (per the record's title; I did not retrieve the full specification).
• § 102 mapping: A different sample format (particulates on a sampling device), no petroleum, no metasurface toroidal chip, no reference subtraction as claimed, no dual-torus effect.
• Verdict: Anticipates no claim.

4.6 CN 105445219 A — Method for enhancing absorption spectrum signals of biological sample in Terahertz wave band

• Assignee / dates: University of Shanghai for Science and Technology (same assignee as the patent at issue); filed 2016-01-07, published 2016-03-30; granted CN 105445219 B, 2017-12-26. Examiner-cited.
• Disclosure (claim 1): Fill the biological sample between the micro/nano structures on a black-silicon wafer; freeze-dry (−80 °C, 2 h, then vacuum dry 12 h); co-axially place THz source, detection frame and detector in a sealed measurement box; fill with dry gas; when the in-box humidity drops below 5% and is held there, irradiate the wafer; the micro/nano structures cause multiple internal reflections so the THz wave passes the sample repeatedly, lengthening interaction; detect the transmitted wave and compute the enhanced absorption spectrum.
• § 102 mapping: Genuine element-level overlap with E1 — drying the measurement environment before measurement (<5% here vs. the patent's <3%) — and with the general architecture of a THz transmission measurement through a sample carried on a structured medium. Missing: crude oil (E2), pipette, reference-then-subtract normalization (E4), split-ring metasurface, and the dual-torus toroidal effect (E5). The "enhanced absorption spectrum" is obtained by resonant multi-reflection, not by reference subtraction.
• Verdict: Anticipates no claim. Useful §103 art for the "dry-purge + structured-substrate THz transmission" portion of claim 1.
• Flag (post-dated event): A live record dated 2026-07-03 shows CN 105445219 B transferred from USST to 无锡同婳科技有限公司 (Wuxi Tonghua Technology Co., Ltd.), effective 2026-06-16. This does not affect its status as prior art against US 11,346,778, but it does mean the reference is no longer held by the patent's own assignee — worth noting if you are tracking the art for licensing or FTO purposes.

4.7 CN 108414473 A — A kind of terahertz wave band Meta Materials sensor

• Assignee / dates: Chongqing University of Posts and Telecommunications; priority 2018-03-13, published 2018-08-17.
• Disclosure: A THz-band metamaterial sensor (per the record; full text not retrieved).
• § 102 mapping: A sensing element only. No petroleum-detection workflow, no reference subtraction, no dual-torus toroidal effect, no Advantest 7400, no volume/thickness ranges.
• Verdict: Anticipates no claim. Possible §103 art for "THz metamaterial sensor" as a genus.

4.8 CN 108627466 A — A kind of Terahertz Meta Materials device and preparation method thereof of detection circulating tumor cell

• Assignee / dates: Taishan University; priority 2018-06-24, published 2018-10-09.
• Disclosure: A THz metamaterial device plus its fabrication method, for circulating tumor cell detection.
• § 102 mapping: Different analyte (tumor cells), apparatus/fabrication focus, no crude oil, no toroidal effect, no reference-subtraction step.
• Verdict: Anticipates no claim.

4.9 CN 109557050 A — A kind of Terahertz Meta Materials sensor of complementary type structure

• Assignee / dates: Chongqing University of Posts and Telecommunications; priority 2018-11-29, published 2019-04-02.
• Disclosure: A complementary-structure THz metamaterial sensor.
• § 102 mapping: No petroleum, no staggered two-CSRR geometry, no dual-torus toroidal effect, no pipette/oil-sample workflow.
• Verdict: Anticipates no claim.

4.10 CN 109580535 A — For enhancing the metamaterial structure of THz wave detection tissue of biological cells signal

• Assignee / dates: USST (same assignee); filed 2018-12-03, published 2019-04-05; granted CN 109580535 B, 2021-04-30.
• Disclosure (from the B publication): A metamaterial unit comprising a rectangular dielectric substrate, a split-ring high-frequency absorber (opening facing up) sitting between two parallel metal rods of a dual-metal-rod low-frequency absorber; identical units tiled in rows and columns into a full array. The method smears biological sample tissue onto the transmissive dual-band absorbing array so that the sample's characteristic absorption frequency coincides with the designed dual-band absorption frequency, producing resonant amplification, sharpening the characteristic peak, and suppressing noise.
• § 102 mapping: Structurally and methodologically this is the closest of the eleven to claim 1 steps 2–3: sample smeared onto a transmissive metasurface and probed with THz. It even uses a split-ring resonator. Missing for claim 1: crude oil (E2 — the analyte is biological tissue), pipette transfer, reference-spectrum subtraction as the normalization mechanism (E4 — it relies on resonant amplification, and its claimed unit is an apparatus, not a detection method), and, critically, E5 (dual-torus toroidal effect). It also lacks C2 (it is a single split ring plus rods, not two overlapping staggered CSRRs), C3 (no 35/40 µm radii or 4 µm gap), and C5/C6.
• Verdict: Anticipates no claim. The leading §103 reference on the "smear a sample onto a metamaterial and measure in THz transmission" limitation. Note it is the applicant's own earlier same-assignee work.

4.11 CN 109580443 A — Using the method for metallic particles content in Terahertz Technology detection substance

• Assignee / dates: USST (same assignee); filed 2019-01-15, published 2019-04-05.
• Disclosure (claim 1): Dry the sample chamber so in-chamber humidity falls below 3%; place several non-polar-material samples of known metal-particle content into a THz-TDS sample chamber; record their time-domain amplitude peak data; fit content vs. peak into a continuous curve serving as a simulation database; measure an unknown sample's peak and compare it against the database to obtain its content.
• § 102 mapping: The drying limitation is essentially verbatim: the patent's step 1 requires drying "until the humidity is below 3%," and CN 109580443 A requires the chamber humidity "降至3%以下." It also teaches a reference database normalization of a THz measurement. Missing: crude oil (E2), pipette smearing, metasurface/toroidal chip (E2, E5), reference-by-subtraction (E4 exactly), and all dimensional limitations.
• Verdict: Anticipates no claim. Best §103 art for the E1 drying limitation (identical 3% threshold), and again same-assignee art.

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5. Element matrix and bottom line

Conclusion on §102: None of the eleven cited references anticipates claim 1, and therefore none anticipates claims 2–6 either, because every dependent claim incorporates claim 1's limitations. No single reference discloses (a) a crude oil sample, (b) transferred by pipette and smeared on the metasurface of the chip, combined with (c) subtraction of a reference spectrum to yield the oil's transmission spectrum, and above all (d) a chip "designed based on the dual-torus toroidal effect." E5 is the load-bearing novelty, and it appears nowhere in the cited art. My earlier section's characterization of E5 as "the single point of novelty" is therefore confirmed rather than contradicted by the citation record.

Gap worth flagging in the citation record: none of the 11 cited references is a toroidal-dipole / toroidal-metamaterial reference at all (no toroidal-dipole resonator, non-radiating anapole, or magnetoelectric metasurface document). The examiner cited only (i) THz-TDS of rocks/oil (CN 102621083 A; CN 104215603 A), (ii) biological/particulate THz spectroscopy and metamaterial sensors (CN 105445219 A; CN 109580535 A; CN 108414473 A; CN 108627466 A; CN 109557050 A; US 2015/0090881 A1), (iii) general THz material evaluation (JP 2013064646 A), (iv) drying/calibration normalization (CN 109580443 A), and (v) an unrelated RF resonant sensor (US 2004/0233458 A1). If you are building an invalidity theory, the §103 combination must supply the toroidal-effect teaching from outside this citation set.

§103 clusters visible in the art (analytical, not a record of examiner rejections):

• Cluster A — subject matter: CN 104215603 A + CN 102621083 A (crude oil / rock THz-TDS).
• Cluster B — sample-on-metasurface in transmission: CN 109580535 A (best), plus CN 108414473 A, CN 109557050 A.
• Cluster C — drying and normalization: CN 109580443 A (3% humidity; database comparison) + CN 105445219 A (<5% humidity, dry-gas purge).

Each cluster is missing E2 and E5, and clusters A and C are missing the whole metasurface concept.

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6. Other record items

• Non-patent citations (2):
  1. Liang, Li et al., "Research progress of terahertz sensor based on artificial microstructure," Infrared and Laser Engineering, vol. 48, no. 2, pp. 12–28, Feb. 28, 2019. A review of artificial-microstructure THz sensors; § 102(a)(1) printed publication. Generic background — no anticipation of any claim.
  2. Ma, Xin, International Search Report and Written Opinion by CNIPA as ISA, dated Sep. 27, 2020. This is the ISR/WO for parent PCT/CN2020/070089; it is a procedural document recording what the ISA considered relevant, not itself prior art. It is the best available proxy for the search that produced citations 2–11 above.
• Forward citations (post-date 2020-01-02; not §102 art): ZA 202202826 B (African New Energies Ltd, published 2022-12-21, "Fano based crab sensor…") and US 12,546,637 B2 (Saudi Arabian Oil Company, 2026-02-10). Relevant to later-art / FTO context only, especially the ZA document, which indicates continued patenting activity in Fano-based fuel sensors — i.e., the very resonance class the specification disparages.
• "Similar Documents" on the Google Patents page: these are algorithmic similarity hits, not citations. One is worth a second look — CN 111141687 B, Method for detecting petroleum by staggered structure ring dipole chip (published 2022-10-14). Its title is a near-translation of this patent's title, and I flagged in the earlier section that I could not confirm whether it is (i) the Chinese national-phase family member of PCT/CN2020/070089, or (ii) a separate related filing by the same group. Since WO 2021134749 A1 published 2021-07-08 and is confirmed to claim the same 2020-01-02 priority, a CN national-phase entry with a matching 2020-01-02 priority is plausible — but plausible is not confirmed, and I am not asserting family status. If you need that resolved, pull CN 111141687 B on CNIPA/Espacenet and compare its priority number to WO2020CN70089 directly. This is the one open question carried forward from the earlier section, and it remains open.
• Drafting defects carried forward unchanged (restated only because they affect how you quote the claims): "An embodiment of the present utility model" (utility-model phrasing in a US utility patent), and the truncation "1 μm˜μm" on the summary page where claim 5 and the detailed description give 1 μm–3 μm. The authoritative claim text in the full-document section is the controlling version. Also note an OCR artifact in the patent PDF snippet rendering "Advantest 7400" as "Advanced 7400" in one passage; the authoritative text says Advantest.

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7. Uncertainty disclosure

• I could not open the USPTO PatentCenter file wrapper or PACER with the tools available, so the element-by-element mapping in §4 is my analytical mapping of the references' disclosures to the granted claims — it is not a reproduction of the examiner's own rejections. I cannot say from this record what §102/§103 rejections, if any, were made and overcome during prosecution of 17/271,570.
• Full text was obtained and read for CN 105445219 A/B, CN 109580535 A/B, CN 104215603 A, CN 102621083 A, CN 109580443 A and the biblio/claims of US 11,346,778 B1. For JP 2013064646 A, US 2015/0090881 A1, CN 108414473 A, CN 108627466 A, CN 109557050 A and US 2004/0233458 A1 I relied on the record's titles, assignees, dates and abstracts (and, for US 2004/0233458 A1, the '3458 publication's own figure/paragraph listing and its WO 2005/104348 A3 family abstract). Descriptions of those five should be treated as provisional.
• Where the patent's own text and web results conflicted on wording (e.g., "Advantest" vs. "Advanced," "measure a spectrum" vs. "measure the spectrum"), I preferred the authoritative patent text as instructed and did not auto-correct any identifier.

I'll ground this analysis by pulling details on the specific prior-art references listed on the patent page before building the § 103 combinations.

Obviousness Analysis — U.S. Patent No. 11,346,778 B1 under 35 U.S.C. § 103

Analysis date: April 26, 2026 · Effective filing date / critical date: 2020-01-02 (PCT/CN2020/070089; the U.S. application 17/271,570 is a § 371 national-stage entry, so there is no earlier domestic priority).

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1. Threshold: what qualifies as prior art

Because the effective filing date is after March 16, 2013, the AIA version of § 102 applies. All eleven patent references cited on the face of the patent have publication dates from 2004 to 2019-04-05 — every one predates 2020-01-02 and therefore qualifies as prior art under at least § 102(a)(1) (printed publication).

Three of them (CN 105445219 A, CN 109580535 A, CN 109580443 A) are the assignee's own publications and share inventors/directors with the '778 (Zhu Yiming, Zhuang Songlin appear on both sides). This does not remove them from the prior art — they published 4–1 years before the critical date, well outside any § 102(b)(1) grace period, and the § 102(b)(2)(C) common-ownership exception is unavailable to § 102(a)(1) printed publications. They are full prior art, and their existence is significant for the obviousness case (§ 5 below).

Two items on the page are not prior art and I am excluding them:

• Ma, Xin, ISR/Written Opinion (CNIPA), dated 2020-09-27 — post-dates the filing. It is an examiner's search product, not a § 102 reference. It is useful only as evidence of what the ISA considered.
• WO 2021134749 A1 / US 2022/0146419 A1 — the family's own publications; self-art only under § 102(b)(2)(C)/(b)(1) analysis, and post-dating here.

I also flag the page's "Similar Documents" entry CN 111141687 B ("Method for detecting petroleum by staggered structure ring dipole chip"). As previously noted, I cannot confirm family status from this record. If it is the CN family member of this PCT, its publication post-dates the priority date and it is not prior art; if it is a separate earlier filing by the same group, the date must be checked. I am not using it.

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2. Level of ordinary skill in the art (POSITA)

A person with a graduate degree (M.S./Ph.D.) in applied physics, optics, or electrical engineering and ~2 years' experience designing terahertz metamaterials/metasurfaces and operating THz-TDS systems, including standard numerical design tools (CST, HFSS) and standard sample-prep technique for THz transmission measurements. The specification itself is written at exactly this level — it treats purging, reference subtraction, pipette loading, and resonator optimization as background knowledge rather than as invention.

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3. Claim 1 — element-by-element mapping

Claim 1 is a four-step workflow plus one wherein-clause. The mapping below uses only references from the patent's own citation list.

Observation: Every claim-1 step except the wherein-clause is disclosed, often verbatim, in CN 109580535 A — a reference from the same laboratory, in the same technology, addressing the same problem (weak/insufficient signal from trace samples on a THz metamaterial sensor). The sole limitation on which patentability must rest is the toroidal clause.

A separate § 103 point on the wherein-clause's form: "designed based on the dual-torus toroidal effect" recites a design rationale, not a structural parameter. Under In re Schreiber and In re Thorpe, a limitation expressed as a function, result, or intended use does not confer patentability if the prior-art structure inherently possesses the recited capability. If a POSITA following the cited art would produce a chip that exhibits a dual-torus toroidal response, the clause is met regardless of whether the artisan called it that. This materially weakens the clause as a distinguishing limitation.

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4. The gap: is the "dual-torus toroidal effect" limitation met by the art?

This is where the obviousness case is weakest, and I want to be explicit about the limits of what I can verify.

What I can verify from the record: none of the eleven cited references is, by title or abstract, a toroidal-dipole metamaterial. The cited sensor references are:

• CN 108414473 A — circular resonant ring (four oblique gaps) + metal strip offset 1 µm to break x-symmetry → EIT-like effect, high Q, refractive-index sensing, 400–900 GHz.
• CN 109557050 A — complementary (hollowed) structure, right air bar translated 40–45 µm to break symmetry → EIT-like, improved Q and sensing.
• CN 108572162 A/B (same assignee, not on the face but same family of work) — split circular + split square rings as bright/dark modes → EIT-like.
• US 2004/0233458 A1 (Rosemount) — electromagnetic resonant sensor (resonator-based sensing, non-THz).

What I could not verify: I exhausted my search steps before retrieving the full text of the Liang Li et al. review, Infrared and Laser Engineering, vol. 48, no. 2 (2019-02-28) ("Research progress of terahertz sensor based on artificial microstructure"), or the toroidal-metamaterial literature. I therefore cannot confirm from this record whether toroidal-dipole THz metamaterials were in the cited art. Review articles of this type are, however, the classic KSR vehicle — they survey the menu of available resonator mechanisms and thereby supply both teaching and motivation.

Three independent routes an examiner could use to close the gap:

(a) Applicant's own admission (admitted prior art). The specification states: "utilizing the unique electromagnetic characteristics of dual-torus toroidal, instead of one-torus toroidal, such as high Q value, sensitivity to environment, we have designed the staggered toroidal chip." This is an express admission that (i) toroidal resonators existed, (ii) single-torus ("one-torus") toroidal chips existed, and (iii) their high-Q and environment-sensitivity properties were known. The asserted advance therefore collapses to adding a second torus to a known device. Duplication of a known element to intensify a known property, absent unexpected results, is routine (cf. In re Harza). This is the single most damaging passage in the patent for § 103 purposes.

(b) "Obvious to try" / finite menu of predictable solutions. KSR permits rejection where the art presents "a finite number of identified, predictable solutions" and a POSITA would pursue them with a reasonable expectation of success. The cited art establishes that the field was actively mining alternative high-Q resonance mechanisms (LC/dipole → Fano → EIT-like → complementary). Toroidal-dipole resonance is simply another entry on that menu, all serving the same end (concentrated near-field, environmental sensitivity). The Liang Li review, as a survey, would be the natural motivation source.

(c) Structural-obviousness route. Even if the toroidal limitation is treated as requiring structure, the Chongqing art (CN 108414473 A, CN 109557050 A) expressly teaches that coupling two resonator elements into bright/dark mode pairs raises Q and sensitivity. Combining (known toroidal resonator) + (two-element coupled-resonator Q enhancement) yields a two-torus structure. Motivation: the '778 states the goal as "higher sensitivity and stability."

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5. Proposed combinations

Combination A — Claim 1 (all steps except the wherein-clause)

Primary: CN 109580535 A. Secondaries: CN 104215603 A (crude oil analyte), CN 105445219 A (dry-gas purge to <5% RH), CN 102621083 A (reference/sample normalization).

Motivation. All four are in the same field and address the same problem: weak analyte signal and insufficient sensitivity in THz-TDS. CN 109580535 A expressly states its metasurface is "compatible with all kinds of terahertz frequency-domain detection equipment" and "can be used with [the] sample to be tested by simple superposition" — an express teaching to pair the chip with generic THz detection hardware and analyte loading. CN 105445219 A supplies the express reason to purge (avoid moisture degrading the transmitted THz signal). CN 104215603 A supplies the express reason to select crude oil as the analyte (its existing methods were stated to be slow, lossy, or destructive). Expectation of success: high, since each step is a standard, individually verified unit operation.

Combination B — the toroidal limitation

Primary for the gap: the applicant's own admission re: one-torus toroidal structures, optionally supplemented by the Liang Li et al. review (motivation + survey of mechanisms) and by CN 108414473 A / CN 109557050 A (two-element coupling to raise Q). See § 4(a)–(c).

Combination C — Claims 2 and 3 (geometry and dimensions)

Primary: CN 108414473 A. Secondaries: CN 109557050 A; CN 108572162 A/B.

CN 108414473 A discloses a circular resonator ring with gaps and a deliberately offset element to "break the symmetry" and thereby realize a high-Q resonance for refractive-index sensing. CN 109557050 A discloses the same design principle in complementary form (translating an element to break symmetry, expressly to raise Q and sensing performance). Both thereby teach the operative concept of claim 2: two coupled circular split-ring elements whose relative displacement/asymmetry creates the high-Q resonance.

Motivation. (i) Same field (THz metamaterial refractive-index sensing); (ii) same stated problem (Q and sensitivity too low; the references say so expressly); (iii) same stated mechanism (symmetry-breaking between coupled rings raises Q); (iv) the '778 itself frames its benefit as higher Q and stability. KSR: "familiar elements according to known methods … yield[ing] predictable results."

Routine optimization for claim 3. CN 108414473 A gives outer radius 24.0 µm, inner radius 20.0 µm, gap 3.0 µm — the same genus as claim 3's 40/35 µm/4 µm. Under In re Aller and In re Boesch, discovering an optimum value of a result-effective variable is within the skill of the art absent evidence of criticality. The '778 supplies no comparative data showing that 35/40/4 µm is critical; it merely operates at ~0.94 THz, and the cited art already operates over 400–900 GHz. The ~0.94 THz result is a modest extrapolation above the referenced band — a point the patentee could exploit, but without data it is an argument, not evidence.

Combination D — Claim 4 (Advantest 7400, transmission mode)

Selecting an off-the-shelf commercial THz-TDS instrument is a design choice. Notably, CN 108414473 A expressly identifies the problem that "the spectral resolution of the terahertz time-domain spectroscopy system currently used for experimental measurement is low, which affects the accuracy of sensing detection." That is an express motivation to select a higher-resolution commercial system — precisely the justification the '778 advances for the 7400 (2.1 GHz resolution). Claim 4 is the epitome of a non-inventive selection.

Combination E — Claims 5 and 6 (1–10 µL / 1–3 µm; 2 µL / 1 µm)

Pure optimization, and the specification hands the examiner the rationale: "the thickness of the crude oil sample is as small as possible to facilitate the transmission of the terahertz pulse signal." An express direction of preference on a result-effective variable is an obviousness finding under In re Aller. In re Boesch likewise. Claim 6's narrower values are the routine "working example" of Claim 5.

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6. Counterarguments the patentee would raise, and their weight

1. Teaching away. The specification disparages Fano resonance as "distorted … caused by the asymmetry of the Fano oscillation" and "unstable with the long detection time." This is not a teaching away from the claimed subject matter — it criticizes a different mechanism. Under In re Fulton/DePuy, criticism of an alternative approach does not teach away absent evidence that it would have discouraged the skilled artisan from the claimed combination. Weak.
2. Unpredictable art / criticality. The best available rebuttal: metamaterial resonator response is empirically sensitive, so the specific staggered geometry and 35/40/4 µm values might produce non-obvious results. Unsupported on this record — there is no comparative data, no showing of criticality, and no evidence of unexpected magnitude.
3. Secondary considerations. I found none in the record: no unexpected results, no commercial success, no licensing, no long-felt need, no failure of others. (The "no litigation" finding in the prior section is, if anything, consistent with a research-stage patent.) Note also that the assignee's own publication lineage — CN 105445219 A (2016) → CN 109580535 A (2019) → CN 109580443 A (2019) → the '778 — reads as a stepwise, iterative program, which is a mild double-edged sword: it supports "predictable iteration" for obviousness even as it shows a consistent research focus.
4. Procedural posture. It is a reasonable inference (not a verified fact — I have no file-wrapper access) that allowance turned on the toroidal wherein-clause, since the examiner cited 11 references covering everything else. If so, the entire patent's validity is load-bearing on a single functional/design-rationale limitation in Claim 1, and Claims 2–6 all depend from Claim 1. That is a structural fragility worth flagging, and it is also the reason the admission in § 4(a) is so consequential.

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7. Bottom line

Single weakest link in the whole case: the "dual-torus toroidal effect" wherein-clause. Whether the specific prior art list on this page can be combined to render Claim 1 obvious turns on whether (i) a toroidal-dipole metamaterial reference exists in that list (I could not confirm one), and/or (ii) the specification's admission that "one-torus toroidal" chips with known high-Q and environment sensitivity existed is treated as admitted prior art. Route (ii) is available on the face of the patent text and is the strongest single argument for obviousness of the one limitation doing all the work.

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Confidence and verification limits — read this before relying on the above

• Search-step limit reached. I could not retrieve the full text of the Liang Li et al. 2019 review, US 2004/0233458 A1, JP 2013064646 A, CN 102621083 A, CN 108627466 A, or CN 109580443 A. My characterizations of those are based on titles, abstracts, and metadata only, and my assessment of the toroidal-metamaterial prior-art landscape is therefore incomplete, not exhaustive.
• I did not have the file wrapper. All statements about examiner reasoning and the basis of allowance are inferences from the face of the patent, not verified facts. A definitive § 103 opinion requires the USPTO PatentCenter file history (office actions, applicant remarks, any Rule 132 declarations).
• Translation caveat. The CN references are Chinese-language; my quotations are from machine-assisted translations on Google Patents/Espacenet. Claim scope in the original Chinese should be verified for any reference relied on to teach claim 2's specific staggered gap arrangement.
• Drafting defect carried forward. As previously flagged, the summary page reads "1 μm˜μm" — a truncation of "1 μm–3 μm" (per Claim 5 and the detailed description). I have used 1–3 µm and have not auto-corrected the record.
• Not legal advice. This is a technical/analytical assessment, not an invalidity opinion under Graham/KSR as applied by counsel.