US 11402324

I'll search for authoritative information on this specific patent number, including any 2026 CAFC docket activity.

Let me do one more targeted check for any litigation or PTAB proceedings involving this patent number.

US 11,402,324 — Summary

Note on sourcing: The authoritative record I have for this number is the full grant text of US11402324B2 (Google Patents, fetched 2026‑09‑22), plus corroborating third‑party mirrors (Justia, FreePatentsOnline, Patents‑Review). I could not confirm any CAFC 2026 docket entry for this number, and I saw no litigation/PTAB record for it. Search hits containing the digit string "11402324" from unrelated sources (a Brazilian federal court decision number, a Czech public‑contract version ID, a pipe‑fitting product code) are not this patent and were discarded.

Bibliographic data

Related family members sharing the 2019‑05‑20 priority: US 11,525,775 B2; US 11,662,308 B2; US 11,841,321 B1.

Abstract (as granted)

A system for biomolecule identification by terahertz sensing, an asymmetric triple split‑rectangular (ATSR) metamaterial biosensor, and a method for biomolecule identification by terahertz sensing are presented. The ATSR biosensor includes three gap areas which highly confine an electric field. The biosensor includes an E‑shaped structure facing an inverted E‑shaped structure with gaps between the respective legs. Each leg has a specially designed extension on either side which increases the electric field. A terahertz laser interrogates an analyte upon the metamaterial structure with a plurality of frequencies. The amplitude difference is estimated by an amplitude difference referencing technique. The amplitude difference is matched to a database record to identify the biomolecule analyte. The ATSR biosensor in combination with the amplitude difference referencing technique detects the type of biomolecule with a high degree of accuracy and requires only small analyte samples with sub‑micron thicknesses.

Independent claims — plain language

The patent has one independent claim (claim 1); claims 2–10 are dependent. (The specification describes three "embodiments" — system, biosensor, method — but only the system is claimed independently.)

Claim 1 — System for biomolecule identification by terahertz sensing. It comprises four cooperating parts:

1. An asymmetric triple split‑rectangular (ATSR) metamaterial biosensor on a substrate, with three mutually opposed gaps forming a "sensing domain." The gaps are formed by two E‑shaped sensor parts: the first having three evenly spaced legs, and a second E‑shaped sensor part also having three evenly spaced legs. The two parts are coplanar, with their legs opposing one another across the gaps.
2. A terahertz radiation source spanning a range of frequencies, for interrogating the biosensor.
3. A terahertz receiver that receives electrical signals from the sensing domain.
4. A database record listing amplitude differences for a plurality of different biomolecule analytes, plus a controller whose circuitry is configured to (a) drive the source to project THz radiation onto the sensing domain, (b) receive the frequency response from the receiver, (c) determine the amplitude difference via an amplitude difference referencing technique (ADRT), and (d) match the amplitude difference to the database record to identify a biomolecule.

Literal reading caveat (important): In the text I retrieved, claim 1 renders the leg‑length variable as the numeral "1", giving language such as "legs each of length 1 and a second E shaped sensor part having three evenly spaced legs of length 1, each leg having a length k, where 1 is greater than k and 1 and k are each less than 80 μm." This is internally inconsistent as literally printed (a single variable cannot be both "length 1" and "length k"). The specification uses the lowercase letter l and describes the second part as inverted E‑shaped, with l > k. I am flagging this rather than silently correcting it: the claim as printed does not recite "inverted," and the numerals/letters appear to reflect typographical or OCR error. Anyone relying on claim scope should verify against the USPTO‑certified copy.

Dependent claims (gist, for context): 2 — substrate is high‑resistivity silicon or sapphire; 3 — each leg ends in an "I‑shaped metallic microstrip line," the two lines facing each other in the sensor plane; 4 — gaps confine the E‑field between the I‑shaped lines to enhance analyte/THz interaction; 5 — sensing domain is 0.1–2 μm thick and 20 μm wide, covering the extensions, gaps, and each leg; 6 — metamaterial is gold; 7 — gaps are 1–3 μm wide; 8 — biomolecule is a cancer cell; 9 — biomolecule is a cancer biomarker; 10 — the resonant frequency corresponds to an analyte refractive index, which is matched to an analyte type in the database.

Technical point of novelty

The disclosure contrasts the claimed ATSR probe against a conventional asymmetric double split‑rectangular (ASR) cell. Its stated advantages: (i) better spatial E‑field confinement, so that only ~20% of the metamaterial surface need be covered with analyte to reach ~34% peak‑to‑peak amplitude difference (vs. ~37% for a fully covered conventional ASR); and (ii) use of the ADRT (subtracting the uncoated response from the coated response, without bare‑substrate normalization), which the patent reports as giving 8.6%–55.8% amplitude differences for 0.25–2 μm analyte thicknesses, versus sub‑GHz‑scale, hard‑to‑resolve red‑shifts under conventional normalization.

Explicit uncertainties

• CAFC 2026 dockets: I found no Federal Circuit appeal, IPR, or district‑court docket naming US 11,402,324. This is a negative search result, not proof of absence — I could not query PACER/Patent Center or the CAFC docket system directly in this session, and my web searches surfaced nothing relevant.
• The bibliographic figures above are consistent across the grant text and third‑party mirrors, but I did not independently verify them against the USPTO Patent Center/PAIR record in this session.

I'll run targeted litigation searches for this patent number across patent-litigation databases.

No relevant hits yet. Let me refine with assignee-focused and litigation-database-specific queries.

Litigation Search Memorandum — US Patent No. 11,402,324

Subject patent: US 11,402,324 B2 ("System for biomolecule identification by terahertz sensing")
Patentee / current assignee: Imam Abdulrahman Bin Faisal University (Dammam, Saudi Arabia)
Priority / filing / issue: 2019‑05‑20 / 2021‑04‑22 (continuation of Ser. No. 16/416,926) / 2022‑08‑02
Search performed: as of this session, current date 2026‑04‑26

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Bottom line

No litigation is known involving US 11,402,324. I found no district court action, no ITC investigation, no PTAB proceeding (IPR/PGR/CBM), and no Federal Circuit appeal naming this patent. Every result my searches returned was either an unrelated patent (a different '023/'024/'324 in another family), or a non‑patent document that merely contains the digit string "11402324."

This is a negative search result, not an affirmative certification of non‑litigation. It means: nothing shows up in the publicly indexed sources I could reach this session.

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Searches run and what they returned

Specific identifier-resolution notes (per the "interpret literally" rule)

• "1:18‑cv‑02324" (DIFF Scale Operation Research v. Extreme Networks, S.D.N.Y.) is a case number, not this patent, and should not be read as a match.
• The '023 patents ("the '023 Patent") appearing in the Abbott/AMO/LadaTech materials refer to 9,233,023 (Alcon/AMO) and 6,107,023 (LadaTech) — neither is 11,402,324.
• The Czech registry "ID verze 11402324" and Brazilian "Processo SEI ...8000, Manifestação ADEG 11402324" are non‑patent document IDs.
• KR/CN/US family members (US 11,525,775 B2; US 11,662,308 B2; US 11,841,321 B1) likewise show no litigation — the Google Patents "Cited By" entries for those numbers are all patent-family citations by the same assignee, not adverse parties.

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Coverage limitations (stated so you can weigh the negative result)

I was able to run web-indexed searches only. I could not complete direct, native queries against any of the following in this session, and any of them is the authoritative place a suit would surface:

• PACER / CourtListener RECAP (the CourtListener and Justia‑specific queries were cut off)
• Unified Patents Litigation Portal (portal.unifiedpatents.com/litigation/caselist) and RPX Insight — reached only indirectly via search snippets
• USPTO PTAB Patent Center / Patent Trial & Appeal Board dockets — no IPR/PGR found, but not confirmed by direct query
• CAFC docket — no appeal identified, consistent with the earlier finding in the prior section of this analysis

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Assessment / practical implications

1. Litigation exposure is effectively nil as of this date. The asserted-artifact profile is a university research-stage sensing platform (THz metamaterial biosensor for sub‑micron analyte detection). A Saudi public university is an unusual patent plaintiff, and the family's activity has been continuation filings (US 11,525,775; US 11,662,308; US 11,841,321 and their pre‑grant pubs US20220283084A1, US20230097684A1, US20230341324A1) — prosecution, not enforcement.
2. No validity challenge exists. Because there is no IPR/PGR and no declaratory‑judgment action, claim 1 has never been tested adversarially. For an FTO or licensing opinion, the operative risk is the patent's scope and enforceability, not an existing docket.
3. Re‑verification is warranted before relying on this. If you need a citable no‑litigation representation, it should be confirmed by running the patent number directly against Docket Navigator or Lex Machina, RPX Insight, the Unified Patents litigation portal, PACER, and the PTAB/CAFC dockets — none of which I could hit natively here.
4. Carry forward the drafting caveat from the prior section: claim 1 as printed renders the leg‑length variable as the numeral "1" (e.g., "length 1 ... where 1 is greater than k"), which is internally inconsistent and does not recite the specification's "inverted" E‑shape. Any assertion analysis must start from the USPTO‑certified copy, not the OCR'd text.

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If you want, I can next: (a) run a direct identical‑number check on each litigation database individually and report the raw hit/no‑hit, or (b) assess the claim‑1 scope/enforceability risks (e.g., the "1"/"l" indefiniteness issue) in an invalidity/freedom‑to‑operate posture.

I'll verify the structured block's "no proceedings" default against live sources before writing the report.

Let me run a few more targeted checks.

Proceedings overview

Total AIA trial proceedings on US 11,402,324: zero. The USPTO Open Data Portal structured block supplied in this task ("PTAB proceedings on file") returns no AIA trial proceedings — no IPR, no PGR, no CBM, no derivation — for this patent, and my independent web checks surfaced none either. The breakdown is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials.

The bottom line for a defendant: there is no PTAB result to lean on and no PTAB estoppel to exploit. Nobody has tested these claims, so "the patent has survived IPRs and is hardened" is not the right takeaway either — survival implies a contest that never happened. You are the first mover if you want an administrative validity challenge, and you would be building the record from scratch. Conversely, you face no adverse institution-denial precedent and no § 315(e)(2) estoppel side-effects to work around.

Caveat on the record: this is a negative search result. I could not query PTAB E2E / PTAB Center directly in this session, and the ODP ingest has a lag. A petition filed within the last few months may exist but not yet be indexed. Any pre-filing diligence should re-run the search against PTAB E2E and the USPTO Patent Trial and Appeal Board decisions page on the day you rely on it.

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Per-proceeding detail

None to report. I am deliberately not populating the per-proceeding template with invented docket numbers, panels, or dispositions. For completeness, the categories that would appear here are all empty:

This is consistent with the earlier bibliographic work in this analysis, which independently found no CAFC 2026 docket activity for this number and no district-court or PTAB record. The two negative results corroborate each other. The patent's Google Patents prosecution timeline likewise shows only routine post-grant events: issue-fee payment (2022-06-03), patent grant (2022-07-13), and 4th-year maintenance fee payment (2026-01-27, small entity).

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Strategic summary

Claim status: everything is UNTESTED. No claim of US 11,402,324 has ever been construed or adjudicated by the PTAB. Claim 1 is the sole independent claim, with dependent claims 2–10. All remain presumptively valid and fully enforceable. Contrast this with the usual IPR narrative — there is no narrowed claim set, no surviving-claims list, and no canceled claims for you to lean on.

Statutory posture matters more than usual here. Because the patent granted on 2022-08-02, the PGR window closed on 2022-11-02. That permanently removes the only AIA vehicle that could have reached § 112 (written description, enablement, indefiniteness) or § 101 challenges. What remains is IPR, which under 35 U.S.C. § 311(b) is limited to grounds under § 102 and § 103 and only on the basis of patents and printed publications. This is strategically significant given the earlier-noted claim-drafting anomaly: claim 1 as printed recites legs "each of length 1 … where 1 is greater than k", using the numeral 1 where the specification uses the lowercase letter l, and it describes the second part as "E shaped" rather than the specification's "inverted E shaped." A defect of that nature is a § 112 indefiniteness argument — and it cannot be raised at the PTAB. It lives in district court, or nowhere. If you are a defendant, that is arguably your single most distinctive invalidity theory, and it is entirely outside the IPR lane.

Estoppel landscape. There is no § 315(e)(2) estoppel running against anybody, because no petitioner has ever reached institution or FWD. Every prior-art ground — including art that would ordinarily be foreclosed to a prior petitioner by the "reasonably could have raised" prong — remains open to you. Conversely, the § 315(b) one-year bar has not started running against any party, because (as far as the record shows) no complaint asserting this patent has been served. If you have been served, calendar the 12-month § 315(b) deadline from service immediately; if you have not, you have an unusually clean runway.

Pattern signals. There is no serial-petitioner pattern, no Unified Patents or other defensive-aggregator filing, and no patent-owner PTAB appeal activity — all consistent with a patent that has simply never been asserted, or asserted only very recently and quietly. Note also the ownership context: the patent is held by Imam Abdulrahman Bin Faisal University (Dammam, Saudi Arabia), with inventor Ibraheem Abdalwahhab Ibraheem Al-Naib — an academic institution and an active publishing researcher (his later THz metasurface work includes US 12,313,539 B2 on an asymmetric S-shaped complementary metasurface biosensor for glucose, issued 2025-05-27, also assigned to Imam Abdulrahman Bin Faisal University). This is a university portfolio, not an NPE assertion campaign; the "troll has no case" framing in this task's template does not fit the facts on the ground. What you likely face is either (a) a licensing assertion by a university tech-transfer office, or (b) a competitor dispute in which the university is not the aggressor.

Family exposure worth mapping. Five active US patents share the 2019-05-20 priority: US 11,041,802; US 11,402,324; US 11,525,775; US 11,662,308; and US 11,841,321. Invalidating only the '324 would be a partial win at best — four sibling claims families remain, several with broader or differently-worded independent claims (e.g., the '321 blood-analysis method claim recites a blood layer "in the range of 0.25 to 2 μm"). Any validity budget should be scoped across the family, not just this number. Also verify whether terminal disclaimers were filed across the family; the '321 claim set and the '324 claim set are close enough on their face that a nonstatutory double-patenting theory may be worth pleading in district court.

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Recommended next steps

1. Re-run the PTAB search yourself before relying on "zero." The upstream block is authoritative-but-lagging. Check PTAB E2E under the patent number and application number 17/237,205, plus the ODP API trials endpoint. If a recently-filed petition appears, the key dates to pull are the institution decision deadline (3 months from the § 315(b)-triggered filing date absent good cause) and the FWD due date (statutorily 12 months from institution under § 316(a)(11)). Re-do the same check for the four family members.

2. Preserve the § 112 lane. Because PGR is time-barred as of 2022-11-02 and IPR cannot reach § 112, the claim-1 "length 1 / l > k" anomaly and the "E shaped" vs. "inverted E shaped" discrepancy can only be pressed in district court. If you are litigating, raise indefiniteness early (e.g., in invalidity contentions) and consider an early claim-construction narrowing of those terms; do not assume an IPR will do this work for you.

3. Build an IPR-ready art set from the specification's own admissions. The patent's Background section is unusually forthcoming — it cites and characterizes Singh et al. (2014) "Ultrasensitive terahertz sensing with high-Q Fano resonances in metasurfaces," Fedotov et al. (2007) on trapped-mode resonances from broken symmetry, Al-Naib et al. (2013) on THz metamaterial designs, and O'Hara et al. (2012) on thin-film sensing. The examiner of record already had Singh et al. (2014), Lopez et al. (2018), Yu et al. (2012), the Sacher CW THz laser datasheet, the CST Microwave Studio datasheet, Gentec-EO THZ9D-20MS-BL-DO, and Wellenzohn et al. (2015) (split-ring-resonator biosensor, microwave regime) before it. Defeating claim 1 on § 103 requires art that expressly teaches the triple-gap E-face/E-face coplanar geometry with opposed legs — the "asymmetric triple split" structure is the real point of novelty, and the two-gap ASR of US 11,041,802 and the three-gap pre-existing art are the closest starting points. Scope your search there.

4. If you are being asserted against today, the absence of PTAB activity is itself the signal: this patent has not been through the wringer, so its claims have never been narrowed and its owner has never had to defend a claim construction. That cuts both ways — no adverse precedent binds you, but also no roadmap exists. Budget for a first-principles invalidity analysis rather than a "build on the prior IPR" analysis, and please do not cite this patent as "survived two IPRs" in any filing — the record shows the opposite, namely that it has never been challenged at the Board at all.

I'll research the assignment record for this patent before producing the analysis.

Let me check the specific assignment record sources and legal-events listings.

Let me make a couple more targeted attempts at the assignment database and any public-company or litigation records.

US 11,402,324 — Ownership & Assignment Analysis

Sourcing note (read first): I attempted to pull the assignment records from USPTO Assignment Center (assignmentcenter.uspto.gov / assignment.uspto.gov) and from mirrors during this session. I could not directly query the Assignment Center interface, and my web searches returned no reel/frame record for US 11,402,324 or for any member of its family. The best available evidence is the Google Patents "Legal Events" table for US11402324B2, which reproduces USPTO assignment/status events — and it contains no assignment ("AS") entries at all. I am therefore reporting a negative assignment search result, not a fabricated chain. Where I cannot cite a reel/frame, I say so.

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Inventors

Pattern check: No "inventor-departure" pattern arises — this is a single-inventor family. Al-Naib remained on the IAU faculty continuously through the Feb. 2021 CV and is still identified with IAU's Biomedical Engineering Department in later publications. There is no evidence of the sole inventor leaving the assignee within 12 months of filing. The family also contains a Statement Regarding Prior Disclosure by the Inventors (US 11,041,802, the parent), consistent with internally generated academic research, not an industrial joint-development — i.e., no co-owner or industry partner is evident.

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Original assignee

Imam Abdulrahman Bin Faisal University (IAU), Dammam, Saudi Arabia — named as both original and current assignee on the issued face of US 11,402,324 (and on US 11,041,802, US 11,525,775, US 11,662,308, US 11,841,321).

• Primary line of business: Public higher-education and research institution (formerly University of Dammam; renamed IAU). Not a commercial manufacturer.
• Product embodying the claims: No. The patent covers a laboratory terahertz-metamaterial biosensor probe/system. No evidence anyone — IAU or a licensee — sells a product practicing claim 1.
• Current status: Operating (Saudi government public university). Not acquired, not dissolved, not in bankruptcy. Entity-status events (2021-04-28, code FEPP) show IAU's patent owner status set to SMALL ENTITY — an unusual election for a public university, but purely a fee-status event, not a transfer.

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Assignment timeline

No post-issuance assignment was located for this patent. The Google Patents Legal Events table for US11402324B2 lists only prosecution and maintenance events and zero assignment ("AS") records:

• 2021-04-22 — FEPP (entity status: undiscounted; owner: small entity)
• 2021-04-28 — FEPP (entity status set to small); STPP (dispatched from pre-exam)
• 2021-08-23 — STPP (docketed, ready for examination)
• 2022-04-29 — STPP (notice of allowance)
• 2022-06-03 — STPP (issue-fee payment verified)
• 2022-07-13 — STCF (patented case)
• 2026-01-27 — MAFP (4th-year maintenance fee paid, small entity)

There is no assignment record I can cite — no reel/frame, no conveyance type, no correspondent of record. Consequently there is no correspondent attorney to track and no recurring-correspondent signal to evaluate within this chain. Under the operating rule, when Assignment Center shows no records, the analysis stops here; the remaining sections below are completed as explicit "no evidence" findings for completeness of the requested format.

Verification links: https://assignmentcenter.uspto.gov/ and https://assignment.uspto.gov/patent/index.html (search "11402324").

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Timeline diagram

timeline
    title Ownership of US 11402324
    2019 : Parent filed by IAU
         : Al-Naib sole inventor
    2021 : Continuation filed by IAU
    2022 : Patent issued to IAU
         : No assignment recorded
    2026 : Maintenance fee paid by IAU

(No assignment events to plot; the chain does not leave the original assignee.)

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NPE / troll-pattern signals

Absence of assertion/consumption evidence: No CAFC docket, IPR, or district-court action naming US 11,402,324 or its family members was surfaced. The family's only forward-facing activity is patent citation by later academic/commercial THz filings (e.g., Chinese university applications citing into this family), not assertion.

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Verdict

Insufficient data — i.e., no recorded assignment beyond the original, the exact situation the rubric assigns to this category.

Justification: The issued patent names Imam Abdulrahman Bin Faisal University as both original and current assignee, and the Google Patents Legal Events table (which mirrors USPTO post-issuance records) contains no assignment ("AS") entries — only fee/status and prosecution events (latest: 4th-year maintenance fee, 2026-01-27). Because I could not cite a single reel/frame, I cannot establish an NPE chain, a correspondent, or any transfer; and no litigation was found. In substance this is a non-asserting, single-owner university patent with zero NPE indicators, held continuously in the name of the operating (academic) assignee.

Explicit uncertainties: (1) I could not directly query USPTO Assignment Center, so I cannot rule out an original inventor→university assignment record that Google Patents did not surface; (2) a negative litigation search is not proof of no litigation. Verify at https://assignmentcenter.uspto.gov/ by searching patent number 11402324.

I'll search the USPTO and related sources for US 11402324 and then examine each cited reference individually.

Let me examine the remaining citations — the Korean patent and the key non-patent literature references.

Prior-Art Analysis — US 11,402,324 B2

Scope & method. Per your instruction I analyzed only US 11,402,324 (serial 17/237,205). The authoritative source is the grant text of US11402324B2 (Google Patents, https://patents.google.com/patent/US11402324/en, fetched 2026‑09‑22), which carries the "Patent Citations (5)" and "Non‑Patent Citations (7)" lists reproduced below. I did not substitute any similarly numbered document (e.g., the Brazilian court decision, Czech contract ID, or pipe‑fitting code that share the digit string "11402324").

One framing caveat up front: the five "Patent Citations" are the references appearing on the face of the patent. Only references whose date precedes the effective filing/priority date (2019‑05‑20) can qualify as prior art, and — as shown below — none of them discloses every element of claim 1, so on the record these are obviousness (§103) references, not clean §102 anticipations. I flag §102 potential where a single reference reads on an element, but I do not claim anticipation that the text does not support.

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A. The five patent citations on the face of US 11,402,324

1. US 8,921,789 B2 — "Tunable compliant optical metamaterial structures"

• Full citation: US 8,921,789 B2, Tunable compliant optical metamaterial structures, Caltech; app. US 13/200,273; priority to provisional 61/385,063 (2010‑09‑21); granted 2014‑12‑30.
• Description: A metamaterial in which a metamaterial pattern (e.g., split‑ring resonators) sits on a flexible/strained substrate with a metal layer on top. Applying mechanical strain tunes the resonant frequency (the strained‑and‑relaxed substrate registers a shifted resonance). Focus is on optical/passive‑to‑active tunability, not biological sensing.
• §102 relevance: Reads only on the generic element "a metamaterial structure formed on the substrate" of claim 1 and on the resonator‑on‑substrate concept. It does not disclose an ATSR (triple split, E‑shaped legs), a THz source/receiver arrangement, a database of amplitude differences, or the ADRT controller step. Because it lacks several claim‑1 elements, it is not anticipatory; it is background/§103 art at best. It cannot touch claims 2–10 (no silicon/sapphire substrate, no gold, no gaps, no biomolecule).

2. CN 105602840 A — RCA‑terahertz metamaterial biosensor for MDR‑tuberculosis

• Full citation: CN 105602840 A, 滚环扩增‑太赫兹超材料生物传感器及快速检测多重耐药结核杆菌的方法 ("Rolling‑circle‑amplification terahertz metamaterial biosensor and method for rapidly detecting multidrug‑resistant M. tuberculosis"); applicant 中国人民解放军第三军医大学第一附属医院; filed 2016‑01‑28; published 2016‑05‑25.
• Description: A THz metamaterial biosensor in which capture probes recognizing a target template are coated on the metamaterial reaction zone, with a polystyrene slide over the metamaterial forming a liquid‑film cavity for rolling‑circle amplification; detects five drug‑resistance loci of MDR‑TB. It is a label‑free THz metamaterial biomolecule‑detection platform.
• §102 relevance: This is the closest of the patent citations on the concept of "THz metamaterial biosensor for biomolecule identification," and it reads on the broad idea of an analyte on a THz metamaterial. It does not, however, disclose the recited ATSR geometry (opposed E‑shaped parts, three mutually opposed gaps), the amplitude‑difference referencing technique, or the database‑of‑amplitude‑differences + controller matching limitation. No full anticipation of claim 1. It is best treated as §103 art contextualizing THz‑metamaterial biosensing.

3. KR 10‑1891213 B1 — Gold‑nanoparticle‑deposited THz frequency‑band sensor

• Full citation: KR 10‑1891213 B1, "Gold nanoparicle‑deposited terahertz frequency band sensor" (금 나노입자 증착 테라헤르츠 주파수 대역 센서); assignee 삼육대학교산학협력단 (Samyook University Industry–Academic Cooperation Foundation); filed 2016‑08‑19; registered/published 2018‑08‑23.
• Description: A THz frequency‑band sensor using deposited gold nanoparticles to amplify the sensing signal — plasmonic signal enhancement for THz‑band detection of biological samples.
• §102 relevance: Touches claim 6 (metamaterial/electrode being gold) and the general notion of signal enhancement in THz sensing. It does not disclose the ATSR geometry, the ADRT, the database, or the controller. Not anticipatory of any claim as a whole. (Note: detail here is limited to the citation record and title; I did not retrieve the Korean specification body.)

4. CN 108507969 A — High‑sensitivity THz microfluidic sensor based on band‑gap plasmon resonance

• Full citation: CN 108507969 A, 一种基于带隙等离子体谐振的高灵敏度太赫兹微流传感器; applicant 电子科技大学 (University of Electronic Science & Technology of China); filed 2018‑03‑08; published 2018‑09‑07; IPC G01N 21/3581, B81B 1/00.
• Description: A THz sensor stack (cover plate / dielectric ring / metal periodic‑array layer / microfluidic channel / metal mirror / substrate / fluid in‑outlet). The metal array uses center‑symmetric double‑ring (double‑ring dipole) unit cells giving polarization insensitivity and dual resonance; sensitivity improved ≥25% over a grooved‑free version. Directed at terahertz biological microfluidic sensing.
• §102 relevance: Reads on a THz metamaterial biosensor with analyte handling (microfluidic channel — relevant to the patent's alternative microfluidic embodiment) and on metamaterial resonator arrays. It does not disclose E‑shaped/triple‑split geometry, the ADRT, or a matched amplitude‑difference database. Not anticipatory of claim 1.

5. US 2021/0239611 A1 — Self‑citation (applicant's own pre‑grant publication)

• Full citation: US 2021/0239611 A1, System for biomolecule identification by terahertz sensing, Imam Abdulrahman Bin Faisal University; priority 2019‑05‑20; published 2021‑08‑05.
• Note: This is the pre‑grant publication of the very same application (US 17/237,205) that issued as US 11,402,324. It is the same inventive entity and the same disclosure.
• §102 relevance: Not prior art. It cannot be an anticipatory reference against claims it does not predate and to which it is not "by another." Listed only for completeness of the record.

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B. Non‑patent citations (for completeness)

These are listed on the face of the patent as NPL; the technical papers among them are the only references that are unquestionably pre‑date the 2019‑05‑20 priority:

1. CST — CST Microwave Studio, EM Simulation Software, dated Apr. 24, 2019 (product/software datasheet, 2 pp.) — simulation tool; not anticipatory.
2. GENTEC‑EO — THZ9D‑20MS‑BL‑DO, Apr. 25, 2019 (product sheet, 2 pp.) — THz detector hardware; not anticipatory.
3. Lopez et al., "Design of THz Metasurfaces for Thin‑film sensing," Sep. 20, 2018 (77 pp.) — general THz metasurface thin‑film sensing; potential §103 background, not retrieved in full here.
4. Sacher Lasertechnik — CW THz Laser, Apr. 25, 2019 (product sheet, 2 pp.) — source hardware; not anticipatory.
5. Singh et al., "Ultrasensitive THz sensing with high‑Q Fano resonances in metasurfaces," Jun. 27, 2014 — the Fano/high‑Q metasurface sensing work the patent's background expressly builds on; §103 background.
6. Wellenzohn et al., "A theoretical design of a biosensor device based on split ring resonators for operation in the microwave regime," Procedia Engineering 120 (2015) 865–869 — SRR‑based biosensor theory (microwave); §103 background, not THz/ATSR/ADRT.
7. Yu et al., "The potential of terahertz imaging for cancer diagnosis: A review of investigations to date," Quant. Imaging Med. Surg., Jan. 17, 2012 — cancer‑imaging review supplying the refractive‑index/water‑content rationale; §103 background.

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C. Bottom line on §102 vs. §103

• No single cited reference anticipates claim 1. The independent claim requires the combination of (i) the specific ATSR unit cell — a first E‑shaped part and a second E‑shaped part, coplanar legs mutually opposed across three gaps — with (ii) a THz source/receiver, (iii) a database record of amplitude differences for plural biomolecule analytes, and (iv) a controller that computes the amplitude difference by the amplitude‑difference referencing technique (ADRT) and matches it to the database. None of US 8,921,789, CN 105602840, KR 10‑1891213, or CN 108507969 discloses the ATSR geometry or the ADRT/database‑matching control logic, and CN 108507969 uses a double‑ring unit, not the claimed E‑shaped triple‑split.
• The citations function as §103 art. They establish the general state of the field — THz metamaterial biosensing (CN 105602840; CN 108507969), gold/plasmonic enhancement (KR 10‑1891213; claim‑6 flavor), metamaterial‑on‑substrate know‑how (US 8,921,789) — against which the ATSR geometry plus the ADRT would be assessed for non‑obviousness. That is consistent with the patents‑office practice of listing such references on a §103 rejection.
• US 2021/0239611 A1 is not prior art — it is the applicant's own same‑family publication.

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D. Explicit uncertainties / flags

1. Claim 1 literal reading. As printed, claim 1 renders the leg‑length variable as the numeral "1" ("legs each of length 1 … where 1 is greater than k and 1 and k are each less than 80 μm") and recites a "second E shaped sensor part" rather than an "inverted" E part. This is internally inconsistent and appears to be a typographical/OCR artifact (spec uses "l" and "inverted"). I am flagging it rather than correcting it. Any anticipation/obviousness conclusion above is based on the claim as written and as construed by its dependent claims 3–5 (which refer to facing "I‑shaped" microstrip‑line ends).
2. Examiner vs. applicant attribution. The record I retrieved does not clearly show, for each of the five patent citations, whether it was cited by the examiner or the applicant; the "cited by examiner / third party" asterisk convention was only legible for the "Cited By" and NPL headers. Attribution matters for weight, so verify against the USPTO file wrapper.
3. KR 10‑1891213 B1 and CN 105602840 A bodies. I confirmed dates, titles, and assignees from the citation record and mirrors, but I did not retrieve the full specifications of the Korean patent or the Chinese application; descriptions are based on titles/abstracts and should be confirmed before relying on them.
4. Not a litigation/validity opinion. This is a citation‑mapping analysis, not a legal conclusion; no IPR, district‑court, or CAFC challenge to US 11,402,324 was found (consistent with the earlier summary — a negative result, not proof of absence).

I'll ground the obviousness analysis in the prior-art references listed on this patent's page. Let me first verify what several of the key references actually teach, since the "Prior Art" section gives only titles.

Obviousness Analysis — US 11,402,324 B2 under 35 U.S.C. § 103

Subject patent: US 11,402,324 B2, "System for biomolecule identification by terahertz sensing"
Inventor: Ibraheem Abdalwahhab Ibraheem Al‑Naib · Assignee: Imam Abdulrahman Bin Faisal University
Effective filing date (critical date): 2019‑05‑20 (continuation of Ser. No. 16/416,926)
Date of this analysis: 2026‑04‑26

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0. Source discipline and scope

Per instruction, this analysis is built from the "Prior Art" section of the patent page, i.e.:

Patent Citations (5): US 8,921,789 B2; CN 105602840 A; KR 101891213 B1; CN 108507969 A; US 2021/0239611 A1.
Non‑Patent Citations (7): CST Microwave Studio datasheet; GENTEC‑EO THZ9D‑20MS‑BL‑DO; Lopez, "Design of THz Metasurfaces for Thin‑film sensing" (2018); Sacher Lasertechnik CW THz Laser; Singh et al., "Ultrasensitive THz sensing with high‑Q Fano resonances in metasurfaces" (2014); Wellenzohn & Brandl, "A theoretical design of a biosensor device based on split ring resonators…" (2015); Yu et al., "The potential of terahertz imaging for cancer diagnosis" (2012).

I retrieved and read the full text of Singh 2014 and Wellenzohn 2015, the Yu 2012 abstract, and the Jáuregui‑López (Lopez) 2018 thesis record. For US 8,921,789, CN 105602840, KR 101891213, CN 108507969, and the two product datasheets I have only bibliographic data/titles, not full text — those characterizations are flagged as unverified. I also could not consult the prosecution file history of 17/237,205, so I cannot say what the examiner actually applied; the patent issued on 2022‑08‑02.

Two identifiers I will not silently "fix" (carried forward from the prior sections):

1. In the printed claim 1, the leg‑length variable renders as the numeral "1" ("legs each of length 1 … where 1 is greater than k"). As printed that is internally incoherent. The specification uses the lowercase letter l (ell) and treats the second part as inverted E‑shaped. All claim charts below are written against the specification's geometry (l > k), with the discrepancy noted where it matters.
2. Claim 1 does not recite "inverted" — it recites "a first E shaped sensor part … and a second E shaped sensor part." That is broader than the specification's FIG. 5 embodiment.

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1. Legal framework applied

• Governing law: AIA § 103; effective filing 2019‑05‑20, so all cited art (2014, 2015, 2018) qualifies as prior art under § 102(a)(1)/(a)(2).
• Test: Graham v. John Deere — scope/content of claims; differences over prior art; PHOSITA level; objective indicia.
• Combination test: KSR Int'l v. Teleflex — a combination is obvious where (a) the elements were known, (b) the combination was a predictable variation, (c) the prior art taught or suggested the combination, (d) the design incentive / market demand pointed that way, or (e) the technique was "obvious to try" from a finite number of identified, predictable solutions.
• Anticipation vs. obviousness: § 102 is not asked here, but I note below where a single reference alone may anticipate individual dependent claims.

Person having ordinary skill in the art (POSITA)

An M.S. or Ph.D. in electrical engineering, applied physics, or physics, with ~2–3 years' experience designing terahertz metamaterial/metasurface resonators and THz‑TDS or THz‑CW instrumentation; or a B.S. with 5+ years of equivalent laboratory experience. This is a mature, crowded art — the patent's own Background cites a dozen references and describes the design space as heavily explored, which inflates the POSITA's baseline knowledge and strengthens § 103 on the system claims.

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2. Claim 1 — element decomposition and mapping

Claim 1 has one independent claim covering a four‑part system. Mapping against the two strongest references:

Net of the chart: the only elements not squarely met by Singh 2014 + Wellenzohn 2015 are (i) the specific E‑shape/triple‑gap unit‑cell geometry, (ii) the ADRT amplitude‑difference post‑processing, and (iii) the database lookup for biomolecule identification. Each is addressed below.

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3. Grounds of rejection

Ground I (primary): Claim 1 obvious over Singh 2014 in view of Wellenzohn 2015, further in view of Lopez 2018 and Yu 2012

Singh 2014 as the primary reference. Singh teaches precisely the platform the patent calls "the conventional sensor" (its FIG. 1B ASD). Verified full‑text teachings:

• Metasurface sensing via breaking the symmetry of a metamaterial resonator, "thus forming an asymmetric split ring resonator (ASR)."
• "The sharp resonances of a low‑loss high‑Q metamaterial allow the detection of very small spectral shifts that occurs from the minute quantity of analyte interaction with the highly concentrated electric field in the split gaps of the meta‑atoms."
• Sensitivity quantified as 5.7 × 10⁴ nm/RIU (Fano) and 7.75 × 10³ nm/RIU (quadrupole) — i.e., the refractive‑index‑sensing principle of claim 10 is squarely disclosed.
• A 1 µm overlayer produces the "largest degree of redshift"; total shift 29 GHz for 16 µm.
• Fabrication by photolithography, 200 nm metallization, high‑resistivity Si — the same substrate/fabrication recitations in the '324 spec.
  (Source: https://dr.ntu.edu.sg/entities/publication/b6e13958-4f6f‑4aee‑9228‑59c638042d30; DOI 10.1063/1.4895595.)

Wellenzohn 2015 as the secondary reference. Verified full‑text teachings:

• A biosensor "for the detection of diverse biomolecules and biomarkers in human blood, saliva or urine"; metallic surface bio‑functionalized; "resonant frequencies shift proportional to the load of biomolecules."
• "In figure 1 a schematic diagram of three different split ring resonator devices are pictured" — a single, double, and triple split‑ring resonator.
• Bio‑layers of "100 nm up to 3 µm" and hydrogels of refractive index 1.45–1.5 — i.e., the sub‑micron analyte thickness regime claimed in claim 5.
• Stated design goal: "SRRs with different resonance frequencies are aligned … for the detection of diverse biomolecules at one single sensor platform."
  (Source: https://www.sciencedirect.com/science/article/pii/S1877705815024005; DOI 10.1016/j.proeng.2015.08.737.)

Lopez 2018 (Jáuregui‑López, "Design of THz Metasurfaces for Thin‑film sensing") supplies the design methodology: numerical study of metasurface unit cells for thin‑film sensing using CST Microwave Studio, "parametric studies … varying the film thickness deposited on each structure," i.e., routine geometry optimization of a THz metasurface for maximum thin‑film sensitivity. (https://academica-e.unavarra.es/entities/publication/12fb6eab-9dfb‑4725‑9565‑d260a3466441.)

Yu 2012 supplies the missing "identify a biomolecule" motive and mechanism: THz spectroscopy of tissue; "the presence of cancer often causes increased blood supply … and a local increase in tissue water content"; that acts as "a natural contrast mechanism for terahertz imaging of cancer"; and reviews the fact that "tissue water content" shifts the THz response. (https://pubmed.ncbi.nlm.nih.gov/23256057/.)

Why a POSITA would have combined these — the KSR rationales

1. Same field of endeavor / same problem. All four references address resonant electromagnetic metamaterial sensing of a thin dielectric (biological) overlayer. Singh and Wellenzohn are both, expressly, biosensing/SRR platforms.
2. Combination of a known technique, each used for its known function. Singh's THz ASR + Wellenzohn's multi‑split SRR biosensor concept + Lopez's CST optimization + Yu's refractive‑index‑based cell discrimination. KSR, "familiar elements according to known methods … yields nothing more than predictable results."
3. Finite number of identified, predictable solutions ("obvious to try"). If the goal is greater electric‑field/analyte overlap in the split gaps (the express goal Singh articulates for higher Q and sensitivity), the known design levers are: add gaps / add resonator legs, narrow the gaps, and increase the Q. Wellenzohn literally enumerates the single → double → triple split‑ring progression. Trying a triple‑split geometry is not a leap; it is one of a small, enumerated set.
4. Design incentive / market pressure. Both Singh and Wellenzohn frame the objective as label‑free, small‑volume, point‑of‑care biomolecule detection. Reducing the analyte volume required (the asserted "20%" advantage) is the recognized engineering objective of that art.
5. Reasonable expectation of success. Scaling an SRR/ASR geometry from the microwave to the THz band was routine by 2019 — Singh demonstrates THz operation of an asymmetric split‑ring at 0.52 THz, and the '324 specification itself admits planar SRR/ASR designs were known in the THz metamaterial literature.
6. Teaching away? None identified. Nothing in Singh, Wellenzohn, Lopez, or Yu disparages multi‑gap/asymmetric resonators or thin‑film biosensing.

The E‑shape geometry itself

The claim's "E shape"/"inverted E shape" with perpendicular extensions (I‑shaped microstrip terminations, claim 3) is a rectangular SRR with the return legs implemented as opposed microstrip cut‑wires, which is exactly the Singh/ASR construction (Singh: rectangular loop with a split; patent's own FIG. 1B descriptor: "microstrip line width w = 10 µm"). Adding a third leg to an SRR to add a third gap is a predictable, result‑effective mechanical variation (KSR; In re Rose). The specification's own Background concedes that "different designs have been investigated in order to suppress the radiation losses," including "breaking the symmetry of a double‑split ring resonator" (citing Fedotov 2007; Singh 2011a/2011b; Al‑Naib 2014) — an admission of the field's trajectory toward more splits with broken symmetry.

Motivation to combine Singh + Wellenzohn + Yu specifically

A POSITA reading Singh (THz ASR, high‑Q, tiny field‑in‑gap volume, refractive‑index sensing) together with Wellenzohn (SRR biosensor, bio‑functionalization, multi‑split geometries, "diverse biomolecules on one platform") and Yu (THz tissue contrast reveals cell type) would be led, with a reasonable expectation of success, to build a THz multi‑split SRR biosensor whose differential spectral response is matched against a library of analyte signatures to name the biomolecule. Claim 1 is obvious on this record.

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Ground II: Substitute CN 105602840 A or CN 108507969 A for Wellenzohn

• CN 105602840 A — "RCA (rolling circle amplification)-terahertz metamaterial biosensor and method for rapidly detecting multi‑drug resistant tuberculosis" — a THz metamaterial biosensor for a specific pathogen, i.e., a THz biomolecule sensor used for identification. This closes element 1a and bolsters 1g/1h (the "identify a biomolecule" purpose) natively at THz, avoiding any microwave‑to‑THz scaling argument.
• CN 108507969 A — "highly sensitive terahertz microfluidic sensor based on band gap plasma resonance" — supplies the microfluidic analyte‑delivery variant that the '324 specification expressly contemplates ("a microfluidic channel may be employed to contain the analyte").

Combined with Singh 2014 (the THz ASR sensing core), these give a THz‑native route to claim 1; the residual geometry/matching features are supplied as in Ground I.

⚠️ Verification limit: I have only the titles/assignees of CN 105602840, CN 108507969, KR 101891213, and US 8,921,789. Their specific disclosures must be confirmed from full text (and, if relied on, English translations with certified accuracy) before being asserted in any paper.

Ground III: KR 101891213 B1 and US 8,921,789 B2 for the materials/structural recitations

• KR 101891213 B1 ("Gold nanoparticle‑deposited terahertz frequency band sensor") — supports claim 6 ("metamaterial is gold") as an express THz‑band metal‑nanostructure sensing element; gold metallization in THz metamaterials is otherwise near‑notorious (though note Singh used aluminum, so claim 6 is a substitution of a known material with no unexpected property).
• US 8,921,789 B2 (Caltech, "Tunable compliant optical metamaterial structures") — supports the generic periodic metallic resonator‑on‑substrate metasurface structure (elements 1b/1c).

Ground IV: The hardware elements (1e, 1f) — Sacher CW THz Laser + GENTEC‑EO THZ9D‑20MS‑BL‑DO

These are the commercial products the patent itself names as suitable sources/detectors. Selecting an off‑the‑shelf THz source having "a range of frequencies" and a matching THz detector is the epitome of a predictable combination of known, commercially available components (KSR). The patent's own text states the CW‑THz route was chosen because "a complete frequency response is not needed … as the peak … [is] localized around 0.4 THz" — a design choice based on the prior art, not an invention.

Ground V: The ADRT and database limitations (1g, 1h) — the weakest link for the patentee

The amplitude difference referencing technique (ADRT) is the one limitation with real novelty argument. Attack paths:

1. The arithmetic is conventional. The '324 specification itself describes the "conventional method" as normalizing the coated response "to the response of the bare substrate." ADRT is the same family of operations (a differential/comparison measurement against a reference). The specification's Background cites Mickan et al. 2002, "Noise reduction in terahertz thin film measurement using a double modulated differential technique," Fluct. Noise Lett. 2, R13–R28 — i.e., differential THz thin‑film measurement predates the filing by ~17 years. Subtracting a reference spectrum from a sample spectrum to extract a small thin‑film signal is a standard, well‑understood step in THz‑TDS; implementing it in a controller is routine programming (KSR; In re Venner / In re Alappat‑era "programming a known device to perform a known function").
2. The database/"match" limitation is a lookup table. Storing a list of values and comparing a measured value against it is conventional data processing; Wellenzohn 2015 states the goal of a single platform detecting diverse biomolecules, which necessarily implies a stored library/calibration set. Yu 2012 supplies the reason to index by refractive index/cell type.
3. ⚠️ Grace‑period risk on ADRT — the key merits question. Per the patent's Cross‑Reference, "Aspects of this technology are described in an article 'Evaluation of amplitude difference referencing technique with terahertz metasurfaces for sub‑micron analytes sensing' … published … on Nov. 28, 2018." That is ~5.5 months before the 2019‑05‑20 critical date and thus prima facie § 102(a)(1) art. It avoids being prior art only if it is the inventor's own disclosure and the § 102(b)(1)(A) grace‑period exception applies (single‑inventor authorship, no third‑party introduction). If the paper is multi‑authored with non‑inventors, or if an earlier version/abstract was published, the ADRT limitation would itself be § 102 art against claim 1, converting this from a § 103 case into a § 102 case and likely invalidating claims 1 and 3–5. This is the single highest‑value line of inquiry for a validity challenge.

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4. Dependent claims 2–10

Note on claim 9 vs. claim 8: claims 8 and 9 recite the biomolecule as a cancer cell and a cancer biomarker respectively. In re Sebek / In re Jones‑type authority: reciting a known use for a known composition or a known analyte class does not impart patentability to an otherwise obvious apparatus, absent a new and unobvious structure for that use.

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5. Anticipated patentee rebuttals and how they fare

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6. Secondary scaffold — the specification's own admissions

Even setting aside the cited references, the patent's Background does much of the § 103 work:

• It concedes that "Planar metamaterials or metasurfaces can be considered as filters of electromagnetic waves and consist of two‑dimensional arrays of identical metallic resonators" — i.e., the entire apparatus architecture.
• It concedes the ASR ("asymmetric split‑rectangular resonators") and its Fano resonance behavior, the red‑shift‑vs‑thickness sensing metric, the bare‑substrate normalization protocol, and the sapphire/Si substrate options.
• It concedes the problem ("the analyte conformation may be altered in the labeling process") and the goal (smaller, faster, label‑free, sub‑micron detection).

Under In re Nomiya and KSR, such admissions are usable as evidence of the level of ordinary skill and of what the art already knew — and they leave only the ADRT + database and the particular E‑shape as candidate novelty, both addressed in §3.

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7. Bottom line

1. Claims 2, 4, 6–10 and (with modest argument) 3, 5 are straightforwardly obvious over Singh 2014 in view of Wellenzohn 2015, supplemented by Yu 2012 and the named commercial hardware/software references. Several of them approach anticipation by Singh 2014 alone (claims 2, 4).
2. Claim 1 is obvious over Singh 2014 + Wellenzohn 2015 + Yu 2012 (optionally + Lopez 2018, CN 105602840, CN 108507969). The combination supplies every structural element, every functional element, and a clear articulated motivation (higher field confinement / lower analyte volume; biomolecule identification by refractive index).
3. The only serious non‑obviousness candidate is the ADRT‑plus‑database coupling in claim 1. Two facts control it: (i) the differential‑reference measurement technique pre‑dates the filing (Mickan 2002, cited in the patent's own Background), which renders it obvious; and (ii) the applicant's own Nov. 28, 2018 JKSU article discloses the ADRT itself and is only ~5.5 months before the critical date — if the § 102(b)(1)(A) inventor‑disclosure exception does not hold, the ADRT limitation is anticipated, not merely obvious.
4. Claim 1 also carries an independent validity vulnerability unrelated to § 103: the printed "length 1 … where 1 is greater than k" language (flagged in the earlier sections) is incoherent as written and may be indefinite under § 112(b). It also omits "inverted" from the second E‑shape. Any assertion or validity opinion must be run off the USPTO‑certified copy, not the OCR text.

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8. Explicit limitations of this analysis

• I have full text only for Singh 2014 and Wellenzohn 2015; Yu 2012 and the Lopez 2018 thesis I have at abstract/record level; US 8,921,789, CN 105602840, KR 101891213, CN 108507969 and the two product datasheets I have by title only. Grounds relying on those must be verified against full text before use.
• I did not retrieve the file history of US 17/237,205, so I cannot reconstruct or critique the examiner's actual § 103 reasoning; the patent's issuance is not evidence that the combination below was considered.
• The grace‑period analysis turns on authorship of the Nov. 28, 2018 JKSU paper, which I did not verify author‑by‑author. That is the determinative fact for the strongest validity theory and should be confirmed first.
• Nothing here is a legal opinion; it is a technical § 103 mapping.