US 9168698

I'll search for authoritative information on US patent 9168698, including USPTO records and any CAFC 2026 docket activity.

Let me specifically check for any CAFC 2026 appellate docket activity involving this patent.

US Patent 9,168,698 — Search Summary

Scope note on "CAFC 2026 dockets": I found substantial 2026 docket activity in the Stratasys/Bambu Lab dispute, and PTAB activity directly on the '698 patent, but I did not find a Federal Circuit appeal docket that names 9168698 itself. See "Litigation status" below for what I did and did not find.

Bibliographic data

Abstract (as printed)

"An extruder or other tool head of a three-dimensional printer is instrumented to detect contact force against the extruder, such as by a build platform or an object being fabricated. The tool head may also be instrumented to detect deflection forces and the like acting on the tool that might indicate an operating error. The resulting feedback data can be used in a variety of ways to control operation of the three-dimensional printer during fabrication or diagnostics."

Overview of the independent claim (claim 1) in plain language

Claim 1 is a method claim with four steps:

1. Identifying build instructions for fabricating an object;
2. Initiating a build on a 3D printer that has a fabrication tool plus one or more sensors mechanically coupled to that tool, where the sensor(s) are configured to detect a current contact force between the tool and a separate structure;
3. Detecting the current contact force from a sensor signal; and
4. Creating a control signal to control at least one component of the printer in response to that contact force while depositing material during the build.

The key inventive thrust is closed-loop: measure force between the tool head (e.g., extruder) and something it touches (build platform or part), then actively control the printer in real time while material is being deposited.

Representative dependent claims (not independent, but they map the disclosure's commercial significance): claim 2 (tool = extruder); claim 3 (component controls build-material feed rate); claim 4 (component controls z-distance between extruder and build platform); claims 5–7 (compare current to expected contact force → adjust parameters, or terminate the build on a fabrication error); claim 8 (change distance between tool and structure); claim 9 (change extruder feed rate); claims 10–11 (detect planarity of the surface from multiple force measurements, then fabricate a leveling layer that reduces surface irregularities — the "bed leveling" functionality); claim 12 (build instructions explicitly specify a target contact force); claims 13–15 (sensor types: strain gauge, piezoelectric, capacitive/optical/electromechanical/electromagnetic/acoustical).

Family / related patents

• US 10,556,381 — continuation of 14/065,516 ('698), filed Oct. 26, 2015; this one claims the apparatus ("A three-dimensional printer comprising: a fabrication tool... one or more sensors... a controller configured to... calculate the contact force").
• US 10,994,462 ("Planarizing build surfaces in three-dimensional printing") — descended from a later application (16/784,889, filed Feb. 7, 2020), also claiming the Oct. 29, 2012 priority.
• The wider MakerBot/Stratasys family includes US 9,233,504 (tagged build material) and US 9,475,233 (cavity filling).

Litigation / post-grant status (2025–2026)

PTAB — directly on the '698 patent:

• IPR2025-00531, Shenzhen Tuozhu Technology Co., Ltd. et al. v. Stratasys, Inc. et al., filed Feb. 4, 2025; respondent application number 14065516 and respondent patent number 9168698. Status: Trial instituted; institution decision date Oct. 5, 2025. Counsel: petitioner — Joshua Griswold et al.; respondent/patent owner — Brian Oaks et al.
• The Google Patents page for the '698 patent also flags this proceeding under "Family has litigation — PTAB case IPR2025-00531 filed (Pending – Instituted)."

District court:

• Google Patents lists three asserted U.S. district court cases on the patent's litigation tab: Texas Western District Court 1:24-cv-01511; Texas Eastern District Court 2:25-cv-00465; and Texas Eastern District Court 2:24-cv-00644.
• Eastern District of Texas (Marshall Division), jury verdict Sept. 17, 2026 in the first of two Stratasys v. Bambu Lab trials: the jury found four Stratasys patents valid and willfully infringed — US 9,421,713, US 7,555,357, US 9,168,698, and US 10,556,381 — awarding ~$27.6 million in past damages. Press accounts attribute roughly $2.8 million of that total to the two force-detection patents ('698 and '381) combined. Judge Rodney Gilstrap declined to enhance damages despite the willfulness finding and did not enter a permanent injunction. Defendants named: Shanghai Lunkuo Technology, Tuozhu Technology Ltd., Shenzhen Tuozhu Technology, and Bambulab Ltd.

CAFC — what I found and what I did not:

• The only Federal Circuit appeal I could confirm in this dispute in 2026 relates to US 9,421,713 (the purge-tower patent), where Bambu Lab appealed after the PTAB upheld validity — not to 9168698.
• Bambu Lab has publicly stated it will seek post-trial review and appeal of the September 2026 Texas verdict, which would encompass the '698 patent; as of my search, I found no CAFC docket number naming 9168698, and no notice of appeal docketed specifically for it. A notice of appeal for the whole judgment, if filed, would likely be found under the district court case number rather than the patent number.

Uncertainty / confidence notes

• High confidence on bibliographic data, abstract, claim text, and the PTAB IPR2025-00531 record — these are corroborated across Google Patents, Justia, Patents-Review, and the IPR case tracker.
• Moderate confidence on the litigation narrative: the $27.6M figure, the Sept. 17–18, 2026 timing, and the ~$2.8M apportionment to the force-detection patents come from secondary press reports (TCT, 3DPrint.com, 3DPrintingIndustry, SlashGear, VoxelMatters, Chinese trade press), not from the docket itself. The apportionment figures in particular vary slightly across outlets (one reports "$26.7M" vs. "$27.6M").
• Explicit non-finding: I could not verify any CAFC 2026 docket on 9168698. If such an appeal exists, it is very recent (likely post-September 2026) and would be indexed under the Eastern District of Texas appeal rather than by patent number. I would treat any statement that the '698 patent itself is on appeal at the CAFC as unconfirmed.
• One outlier search hit did surface an unrelated uses of the digit string "9168698" (a Japanese patent number for fatty-acid ester separation, documented in a Spanish-language journal index). Per your instruction to interpret identifiers literally, I flag it but do not treat it as the U.S. patent — it is a coincidental number collision in a different jurisdiction and technology.

I'll search for litigation involving US patent 9168698.

Let me get more detail on the specific case numbers and parties.

Let me verify the current status of the PTAB proceeding and any appeal.

Litigation Involving U.S. Patent No. 9,168,698 ("Three-Dimensional Printer With Force Detection")

I searched Unified Patents, RPX Empower, CourtListener/govinfo, Justia Dockets, IPVerse (GreyB), and industry/trade press. Patent 9,168,698 ("the '698 patent") appears in a cluster of related proceedings between Stratasys, Inc. (current assignee, formerly MakerBot Industries LLC) and the Bambu Lab corporate family. Below are the specific matters. (Note: the identifier searched was exactly 9,168,698; I did not substitute the related '381, '713, or '464 patents except where they bear directly on these same cases.)

1. Stratasys, Inc. v. Shenzhen Tuozhu Technology Co., Ltd., et al. — the infringement case (lead case)

• Plaintiff: Stratasys, Inc.
• Defendants: Shenzhen Tuozhu Technology Co., Ltd.; Shanghai Lunkuo Technology Co., Ltd.; BambuLab Limited; Tuozhu Technology Limited (collectively "Bambu Lab").
• Jurisdiction: U.S. District Court for the Eastern District of Texas, Marshall Division (Judge Rodney Gilstrap).
• Case No.: 2:24-cv-00644-JRG (Lead Case; consolidated with 2:24-cv-00645-JRG and, later, the transferred 2:25-cv-00465-JRG).
• Filing date: August 8, 2024.
• '698 patent role: One of the asserted patents. Stratasys's Second Amended Infringement Contentions assert claims 1, 2, 3, 4, 5, 7, 8, 9, 10, 12, and 15 of the '698 patent, accusing the Bambu Lab A1 and A1 mini printers (eddy/force sensor used for nozzle-clumping detection, stopping a print job on detected force).
• Outcome / status: After a week-long trial, on September 17, 2026 a Marshall Division jury found four Stratasys patents — including the '698 patent — valid and infringed, found the infringement willful, and awarded approximately $27.6 million in past damages. (The fifth trial patent, '660, had been invalidated by the PTAB and was not presented to the jury.) Bambu Lab has stated it disagrees and intends to seek post-trial review and appeal. No final judgment or injunction has been entered as of the latest reports; enhanced damages from the willfulness finding are a possibility.
• Sources: https://www.govinfo.gov/app/details/USCOURTS-txed-2_24-cv-00644/ ; https://www.mcdermottlaw.com/news/mcdermott-wins-27-6m-jury-verdict-for-stratasys-in-patent-trial/ ; https://3dprintingindustry.com/news/new-update-in-stratasys-v-bambu-lab-patent-infringement-action-[254833](/patent/254833)/ ; https://www.tctmagazine.com/stratasys-awarded-27-6-in-damages-in-first-of-two-patent-infringement-cases-against-bambu-lab/

2. Stratasys, Inc. v. Shenzhen Tuozhu Technology Co., Ltd., et al. — the second infringement case (member case)

• Plaintiff/Defendants/Jurisdiction: same as above.
• Case No.: 2:24-cv-00645-JRG (Member Case; consolidated with the '644 lead case for all pretrial issues on Oct. 22, 2024).
• Filing date: August 8, 2024.
• '698 patent role: Not asserted in this case — the '645 case asserts a different patent set (U.S. Pat. Nos. 10,569,466; 11,167,464; 8,747,097; 11,886,774; 8,562,324). I include it because it arises from the same dispute and is consolidated with the case that does assert '698. A separate trial for this case had not been scheduled per Stratasys's post-verdict statements.
• Sources: https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557241](/patent/1557241)/download-documents ; https://3dprint.com/[333013](/patent/333013)/stratasys-wins-27-6m-in-patent-case-against-bambu-lab/

3. BambuLab USA, Inc., et al. v. Stratasys, Inc. — declaratory judgment action

• Plaintiffs: BambuLab USA, Inc.; BambuLab Limited; Shanghai Lunkuo Technology Co., Ltd.; Shenzhen Tuozhu Technology Co., Ltd.; Tuozhu Technology Limited.
• Defendant: Stratasys, Inc.
• Jurisdiction/Case No.: Originally filed in the U.S. District Court for the Western District of Texas, Austin Division — 1:24-cv-01511-ADA (Judge Alan Albright). Filed December 9, 2024. On May 2, 2025, Judge Albright granted Stratasys's motion to transfer; the case moved to E.D. Tex. and was renumbered 2:25-cv-00465-JRG, then consolidated into lead case 2:24-cv-00644.
• '698 patent role: The DJ complaint sought declarations of non-infringement and/or invalidity of ten patents, expressly including the '698 patent (along with '381, '466, '464, '324, '097, '713, '357, '660, and '774).
• Outcome / status: Stratasys filed an answer denying the DJ allegations (asserting Bambu does infringe). After transfer/consolidation, the DJ claims were folded into the consolidated E.D. Tex. proceeding; the Feb. 24, 2026 docket-control motion was denied as moot in light of consolidation.
• Sources: https://dockets.justia.com/docket/texas/txwdce/1:2024cv01511/1172816237 ; https://www.courtlistener.com/docket/70133404/54/bambulab-usa-inc-v-stratasys-inc/ ; https://www.law360.com/cases/6757afb0d0fbf70f3051c7db/articles

4. PTAB — Shenzhen Tuozhu Technology Co., Ltd., et al. v. Stratasys, Inc. (IPR of the '698 patent)

• Petitioner: Shenzhen Tuozhu Technology Co., Ltd. et al. (Bambu Lab entities).
• Patent Owner / Respondent: Stratasys, Inc.
• Proceeding: IPR2025-00531 (challenging U.S. Patent No. 9,168,698 B2; Respondent Application No. 14/065,516; Tech Center 1700).
• Filing date: February 4–5, 2025.
• Status: Institution granted / "Trial Instituted" — institution decision dated October 5–6, 2025. The '698 IPR remains pending (a final written decision would not be expected until roughly October 2026). This is a PTAB proceeding, not a district-court case.
• Sources: https://litigation.rpxcorp.com/ptab/18626-shenzhen-tuozhu-technology-v-stratasys-incorporated-ipr-of-698 ; https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2025-00531

Notes, caveats, and one date flag

• The '698 patent is asserted in the E.D. Tex. '644 lead case (item 1) and challenged in IPR2025-00531 (item 4). Those are the two live merits proceedings squarely directed at '698. The DJ action (item 3) also named '698 but has been consolidated into item 1.
• Related but distinct proceedings (same dispute, not directed at '698): the UPC Hague Local Division preliminary-injunction decision of April 24, 2026, concerned EP2964450 (the European counterpart of US 9,421,713, the purge-tower patent), not '698; Stratasys did not appeal. The PTAB invalidations also involved US 9,592,660 and US 8,562,324, not '698. I flag these only to avoid confusion, since press coverage bundles them together.
• Date discrepancy: Your prompt states the current date is April 26, 2026, but the sources describe a September 17, 2026 jury verdict and post-verdict statements (and my operating date is September 29, 2026). Per your instruction to prefer search results over assumptions, I have reported the verdict and subsequent events as the sources describe them rather than treating them as future events. If you are working from an April 2026 litigation snapshot, the verdict in item 1 would not yet have issued as of that date.
• Outcome caveats: The $27.6M figure is a jury verdict on past damages, not a final judgment; it is subject to post-trial motions (including possible enhancement for willfulness), a potential injunction/ongoing-royalty determination, and appeal. Bambu Lab has stated its intent to seek post-trial review and appeal.
• I could not, within this session, retrieve a final written decision in IPR2025-00531 or a CAFC appeal docket number specifically for the '698 patent; the reported CAFC appeal concerns the '713 purge-tower IPR. I flag that as a gap rather than guessing.

I'll reconcile the empty ODP block against the IPR the prior section already flagged, and try to pull claim-level detail.

Now let me look for the institution decision itself, any final written decision, and whether more than one petition targets the '698 patent.

Let me check whether a final written decision or oral hearing has occurred, and whether a second petitioner filed against the '698.

Contradiction flagged up front

The structured "PTAB proceedings on file" block supplied with this task states that the ODP API returns no AIA trial proceedings for the '698 patent and that the "default should be 'no PTAB activity on file.'" Live web search contradicts that, and I am preferring the search results per the operating rules. Paper-level PTAB documents hosted on the USPTO's own PTACTS repository (ptacts.uspto.gov) name IPR2025-00531 against U.S. Patent No. 9,168,698 — including the Director's referral decision and the patent owner's discretionary-denial brief. The ODP ingest is evidently stale/incomplete for this case. The "no PTAB activity" default is wrong here.

Proceedings overview

One AIA trial proceeding on file against US 9,168,698 — IPR2025-00531, Shenzhen Tuozhu Technology Co., Ltd. v. Stratasys, Inc. — status instituted and pending (not settled, not terminated, no FWD yet); zero claims invalidated, zero claims sustained, zero institution denials on this patent. Bottom line for a defendant: this is not a hardened patent, but it is also not a dead one. All 15 claims are under live review with a Final Written Decision statutorily due ~2026-10-07 (≈8 days from today), while the same claims were simultaneously found valid and infringed by a Texas jury on 2026-09-17. You are walking into a patent whose IPR outcome is unknown, whose patent owner has already beaten a validity challenge at trial, and whose IPR deadline has almost certainly not yet produced a written decision.

IPR2025-00531 — Shenzhen Tuozhu Technology Co., Ltd. v. Stratasys, Inc.

• Type: Inter Partes Review (35 U.S.C. §§ 311–319)
• Filed: 2025-02-05 (PTACTS litigation-disclosure documents and ex parte.ai list 2025-02-05; aggregators ipverse.greyb and RPX list 2025-02-04/2025-02-05 — treat the filing date as early February 2025)
• Patent: U.S. Patent No. 9,168,698 B2, application 14/065,516, Tech Center 1700
• Status: Trial Instituted (verbatim from structured aggregator data). Plain English: the Board found a reasonable likelihood that Petitioner prevails on at least one challenged claim and set the case for trial on the merits.
• Judge panel: Not found in the sources retrieved. I located no public designation of the three-APJ panel for this proceeding. I will not guess names.
• Counsel: Petitioner — Joshua Griswold et al.; Patent Owner (Stratasys) — Brian Oaks et al., McDermott Will & Emery LLP (per ipverse.greyb case details and PTACTS filings).
• Petition grounds (all four grounds are § 103 obviousness; no § 102 anticipation ground and no § 112 ground was identified):
  • Ground 1A — claims 1-6 and 8-15 obvious over Warren (U.S. Patent No. 6,986,739), a single-reference obviousness theory premised on combining different disclosed embodiments within Warren (its "vibro-sensoric" contact-force sensing with its through-nozzle dispenser).
  • Ground 1B — claims 3, 7, and 9 obvious over Warren in further view of Eshed (U.S. Pub. No. 2007/0179656), added to teach terminating a build upon detecting a fabrication error.
  • Ground 2A — claims 1-5, 7-10, and 12-15 obvious over Calderon (U.S. Patent No. 6,629,011) in view of RepRap20208 (a 2009 online forum thread), the combination supplying a strain gauge on the extruder mount for both Z-calibration and in-build collision detection.
  • Ground 2B — claim 11 obvious over Calderon + RepRap20208 in further view of Napadensky (U.S. Patent No. 9,031,680), added to teach leveling a deposited layer to decrease irregularities.
  • Claim coverage: all of claims 1-15 are challenged. Note the asymmetry, which matters defensively: claim 6 rests only on Ground 1A (Warren alone) and claim 11 rests only on Ground 2B. The remaining claims (1-5, 8-10, 12-15) are supported by two independent grounds, and claims 3, 7, and 9 by three.
• Discretionary denial fight (unusual, and it is the most important procedural event so far):
  • Stratasys filed a Request for Discretionary Denial under § 314(a)/Fintiv and the Acting Director's 2025-03-26 "Interim Processes for PTAB Workload Management" memo — Paper 7 in this case (patent owner's brief docketed at ex parte.ai doc 7; https://ai-lab.exparte.com/case/ptab/IPR2025-00531/doc/7). Stratasys argued the parallel E.D. Tex. case would reach jury trial months before any FWD, that Judge Gilstrap denies >85% of stay motions, and — notably — preserved an argument that the Commerce Secretary's directives might bar foreign petitioners from using the PTAB against a U.S.-invented, U.S.-owned patent (Ex. 2008, Lutnick nomination hearing transcript).
  • Petitioner opposed (Paper 9) with a broad Sotera-style stipulation not to pursue the IPR grounds in district court and evidence that the patent had never been "commercialized, asserted, marked, licensed, or otherwise applied" in Petitioner's technology space.
  • Acting Director Coke Morgan Stewart denied discretionary denial in Paper 10 (2025-07-17) and referred the petitions to the Board. Quoting the decision: "IPR2025-00531, however, presents different circumstances. The patent challenged in that case has been in force for approximately 10 years, creating strong settled expectations for Patent Owner. Petitioner, however, presents evidence that the challenged patents have never been 'commercialized, asserted, marked, licensed, or otherwise applied' in Petitioner's 'particular technology space.' … This evidence weighs against Patent Owner's claim of strong settled expectations." The decision also recorded that "the projected final written decision due date in the Board proceeding is October 7, 2026," and that the district court trial was then scheduled for 2026-06-01. Paper 10 also barred reharing/Director Review requests until the Board ruled on institution. (Text reproduced at https://klarquist.com/wp-content/uploads/2025/08/CLE-Delegation-Deference-and-Denials-August-2025.pdf and https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557241](/patent/1557241)/download-documents?artifactId=kuA2gbCcQIusWOv24YErJO2AFC12W-n0fDl4HmVH2MkGBaPa4V3_6bE.) Note the same Paper 10 covered five Stratasys patents: IPR2025-00438 ('466), IPR2025-00531 ('698), IPR2025-00532 ('381), IPR2025-00585 ('464), and IPR2025-00611 ('774).
  • Paper 10 has already been cited as authority against patent owners in later Director decisions (e.g., for the proposition that our patent's long time-in-force is outweighed by non-commercialization/non-assertion evidence). It is becoming a small piece of Director-level precedent.
• Institution decision: Instituted 2025-10-06 (RPX Empower lists institution 2025-10-06; ipverse.greyb lists the institution decision date as 2025-10-05 — the one-day discrepancy is likely a time-zone/indexing artifact and I flag it rather than resolve it). Chinese trade press reported on 2025-10-06 that the '698 IPR was among four of five Tuozhu petitions granted on that date, with IPR2025-00585 denied institution. Reasoning of the institution panel: not retrieved. I did not obtain the Board's institution decision text, so I will not characterize why it instituted beyond the statutory "reasonable likelihood" standard. Patent Owner's preliminary response (docketed, arguing (i) no motivation to combine different Warren embodiments, (ii) RepRap20208 is not a printed publication, (iii) Warren citations do not match the reference, and (iv) Grounds 1A/2A fail multiple elements of claim 1) is at https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557345](/patent/1557345)/download-documents?artifactId=whnl0UO1rY_N3994OC9EruGuW-heINRAc9qqH7fgwErEMeojPbKWbTA — those were preliminary-response arguments, not the Board's findings.
• Final Written Decision: NOT ISSUED as of 2026-09-29, so far as I can determine. Statutory deadline 2026-10-07 (one year from institution under § 316(a)(11); matches the Board's own projected due date recorded in Paper 10), extendable up to six months for good cause. No claim has been canceled and no claim has been sustained. Any statement that claims of the '698 patent were held unpatentable would be wrong — that outcome belongs to different Stratasys patents ('660 and '324) in this campaign, not to the '698.
• Settlement / termination: None found. The case remained in trial as of the latest indexed data (ipverse.greyb "Trial Instituted"; Petitions 1557241 dated in the case record).
• Appeal: None — and none is possible yet. No FWD = nothing appealable to the Federal Circuit. The only confirmed CAFC appeal in this dispute is Bambu's appeal of the '713 purge-tower FWD (where the Board found Petitioner had not shown unpatentability), which involves a different patent.
• Defensive value: The claims you are being asserted against are live but unadjudicated. If the FWD cancels claims 1-15, your § 315(e)(2) estoppel exposure is defined by Petitioner's grounds (Warren, Calderon, RepRap20208, Eshed, Napadensky) and you may be facing a materially narrowed patent — but only after 2026-10-07, and every day of delay past that date raises the odds of an extension to as late as ~2027-04-07. Conversely, if the Board sustains claim 1, you are facing a patent that has now survived both a jury validity verdict (2026-09-17) and an instituted IPR. Do not build a clearance or settlement position on the assumption that this patent is already dead.

Strategic summary

Claim-by-claim status of US 9,168,698. Nothing is CANCELED. Nothing is SUSTAINED by the Board. All 15 claims are UNTESTED at the FWD stage and simultaneously subject to a live instituted IPR. The final arbiter so far is the jury, not the Board: on 2026-09-17 the E.D. Tex. jury found the '698 patent valid and infringed (part of the four-patent, ~$27.6M verdict that the prior section covered). So the realistic posture today is a patent with a jury validity win in hand and a pending IPR decision imminent — a genuinely unsettled asset, not a hardened one and not a broken one. The two claims with the thinnest PTAB support are claim 6 (only Ground 1A, Warren alone → easiest to attack on the "no motivation to combine embodiments within a single reference" theory Stratasys pressed in its preliminary response) and claim 11 (only Ground 2B).

Estoppel landscape. No estoppel has attached yet — § 315(e)(2) estoppel arises only on final written decision, and there is none. When it does attach, it runs against Shenzhen Tuozhu and its privies (including the Bambu entities named in the Texas cases, to the extent privity is found), barring them from raising in district court any ground they raised or reasonably could have raised: Warren, Calderon, RepRap20208, Eshed, and Napadensky, in those combinations. Practical consequences for a different defendant: (i) those five references are not thereby made unavailable to you — estoppel is party-specific, and the Jury's invalidity case at trial was separately constrained by the court's striking of certain Ground 1-4 and AAPA opinions (Dkt. No. 193 rulings), so there is real prior art in the trial record that the PTAB never reached; (ii) conversely, Stratasys's own conduct is a constraint too — the Sotera-plus stipulation in the IPR took the IPR grounds out of the district court case as to the petitioner, which means the invalidity theories the jury actually heard were narrower than the full art universe. For a new defendant, the un-IPR'd art (and any art that was struck in Texas on disclosure grounds) remains fair game.

Pattern signals. Yes, this is a serial petitioner campaign, all one side: Shenzhen Tuozhu filed five IPRs against Stratasys in Dec. 2024–Feb. 2025 — IPR2025-00257 ('660), IPR2025-00321 ('713), IPR2025-00438 ('466), IPR2025-00531 ('698), IPR2025-00532 ('381), IPR2025-00585 ('464), and IPR2025-00611 ('774). Of these, four were instituted (00438, 00531, 00532, 00611) and IPR2025-00585 was denied institution. Notably, IPR2025-00532 is the close sibling — it challenges US 10,556,381, the continuation of the '698 patent with essentially the same force-detection disclosure — so the Board is effectively reviewing the same inventive subject matter twice in parallel. No defensive aggregator (Unified Patents, RPX, et al.) appears in the chain; this is a competitor-vs-competitor fight, not a troll takedown. On the patent-owner side, Stratasys has been aggressive on procedure — a full discretionary-denial request in each case, including the foreign-petitioner/Commerce-Secretary argument, a Director Review request in the '324 case (rejected), and continued assertion through trial rather than staying. Stratasys also did not appeal the adverse '660 FWD.

Recommended next steps

• Watch the 2026-10-07 deadline daily. The FWD in IPR2025-00531 is due imminently. Pull the actual FWD from PTAB E2E / PTACTS (https://ptacts.uspto.gov/) rather than relying on secondary coverage, and read the claim-by-claim disposition in the Order/Conclusion section — I can tell you the ground structure, but I will not predict which claims survive, and no FWD exists in the record as of today.
• If the FWD cancels claims 1-15, quote the disposition verbatim and check (a) whether claims 6 and 11 fell on their single grounds, and (b) whether Stratasys files a request for rehearing or a Director Review request (which would pause the appeal clock) and then a notice of appeal to the CAFC under § 319 (42 U.S.C. … no — 35 U.S.C. § 319), due within 63 days of the FWD. Any CAFC appeal will be docketed under the PTAB proceeding, not under "9168698," so search by IPR2025-00531 on CourtListener and the CAFC docket.
• If the FWD sustains claim 1, your invalidity path is the district-court art that the Board did not reach, plus the constitutionality/§ 311(b) limits on what IPR can address (printed publications only — note that a system/instrumentality prior art or an on-sale/public-use theory is categorically unavailable in this IPR and was not tested there). Also weigh the 2026-09-17 jury validity finding: a second bite on the same art in a new case will be an uphill estoppel-of-verdict and res judicata-adjacent fight against Stratasys.
• Do not assume the ODP "no PTAB activity" answer is correct for any Stratasys patent in this family. The ODP ingest missed a fully instituted, Director-referred IPR with public PTACTS filings. Verify every family member ('698, '381, '462, '504 variants) against PTACTS directly.
• Confidence statement: high confidence on the existence, number, parties, grounds, claim sets, the discretionary-denial/Director referral sequence (2025-07-17), institution (2025-10-05/06), and the 2026-10-07 FWD due date. Explicitly not found / not verified: the APJ panel identity, the institution decision's reasoning, any settlement, any FWD (none issued), and any CAFC docket naming this patent or this IPR. The 2025-10-05 vs. 2025-10-06 institution-date discrepancy is unresolved.

I'll research the assignment record for US 9,168,698, starting with the USPTO assignment databases and corroborating sources.

Let me pull the Google Patents legal-events tables for the '698 patent and its siblings, which expose reel/frame data.

Let me try to retrieve the actual reel/frame records directly from the assignment databases and Google Patents legal-events tables.

Assignment & Ownership Reconstruction — US 9,168,698

Source-access caveat (read first). I was able to confirm the existence, type, and dates of the recorded assignments from the authoritative Google Patents legal-events tables reproduced in the provided patent text, but I was unable in this session to retrieve the reel/frame numbers or the recording-correspondent names from the USPTO Patent Assignment Center (assignmentcenter.uspto.gov) or its mirror (assignment.uspto.gov/patent/index.html). Those fields sit behind a POST/session-based search. Per the "don't fabricate" constraint, I report the reel/frame fields as not retrieved rather than guessing. The one reel number that did surface belongs to a sibling application, not to the '698 patent, and is flagged as such.

Inventors

Unusual-pattern check — NOT triggered. The application was filed 2013-10-29 naming MakerBot Industries, LLC as applicant, and all three inventors assigned to MakerBot (recorded 2013-12-30 per the Google Patents legal events). There is no evidence of a coordinated inventor departure within 12 months of filing that would signal an imminent portfolio sale. To the contrary, inventor Kemperle reappears as a named inventor on later MakerBot filings (e.g., U.S. Design Patent D749,155, "Three-dimensional printer frame," App. No. 29/493,503, filed 2014-06-10, assigned to MakerBot Industries, LLC), i.e., he remained with the company well past the 12-month window.

The only mildly notable clerical artifact is a confirmatory assignment from Peter Joseph Schmehl to MakerBot Industries, LLC, Reel/Frame 044593/0383, effective 2013-12-11 — but that record surfaced on the page of the sibling "cavity filling" patent (US 10,836,090 / App. 14/065,449), not demonstrably on the '698 record. It reads as a late-filed "we missed a signature" cleanup (reel 044xxx ≈ a ~2017 recording), not a departure signal. I cannot confirm it covers the '698 patent.

Original assignee

MakerBot Industries, LLC (Brooklyn, NY) — named on the issued patent (App. No. 14/065,516; priority to provisional 61/719,874, filed 2012-10-29).

• Primary line of business: design, manufacture, and sale of desktop fused-deposition-modeling (FDM) 3D printers and related ecosystem (Thingiverse, MakerWare/MakerBot Desktop, filament, Digitizer scanner). An operating company shiping hardware, not a licensing vehicle.
• Products on the market in the relevant window: the Replicator 2 / 2X and subsequent Replicator (5th Gen) / Z18 family. Caution: I could not verify from this session that any specific shipped MakerBot product practiced claim 1 (the "current contact force" detection/leveling feature) — I flag that as unconfirmed rather than assert infringement-by-original-assignee.
• Current status: Acquired by Stratasys, Inc. in 2013 (announced 2013-06-19; the transaction closed in Q3 2013, reported at ~$403M up-front in Stratasys stock). MakerBot operated as a Stratasys subsidiary; its desktop line was subsequently folded into the Stratasys/UltiMaker desktop business. MakerBot is not in bankruptcy and is not a dissolved shell; it exists as a legacy subsidiary entity of a publicly traded parent (Stratasys Ltd., NASDAQ: SSYS).

Assignment timeline

Recorded events confirmed from the Google Patents legal-events table (the only post-filing assignments of record for the '698 patent). Reel/frame and correspondent = not retrieved this session.

• 2013-12-11 (effective, per sibling confirmatory record) / recorded 2013-12-30 — Reel not retrieved

  • Conveyance: Assignment ("ASSIGNMENT OF ASSIGNORS' INTEREST")
  • Assignor: Filipp Gelman; Aljosa Kemperle; Peter Joseph Schmehl (all three named inventors)
  • Assignee: MakerBot Industries, LLC
  • Correspondent: not retrieved. (For context, the patent's prosecution agent/firm of record is Strategic Patents, P.C., per the patent front page and the sibling design patent D749,155 — but prosecution counsel is not the same as the assignment-recording correspondent, and I have not verified the latter.)
  • Context: original inventor-to-employer assignment (ordinary conveyance of employee inventions to the filing entity).

• 2022-07-19 (recorded) — Reel not retrieved

  • Conveyance: Assignment ("ASSIGNMENT OF ASSIGNORS' INTEREST")
  • Assignor: MakerBot Industries, LLC
  • Assignee: Stratasys, Inc.
  • Correspondent: not retrieved.
  • Context: intra-group corporate consolidation — Stratasys had already owned MakerBot since 2013, so this is a subsidiary→parent cleanup of the IP title record, not an arm's-length sale.

No other recorded assignments of record. There is no third-party licensee, security-interest, merger, change-of-name, or release entry on the '698 chain.

Timeline diagram

timeline
    title Ownership of US 9168698
    2012 : Priority from provisional 61719874
    2013 : Filed by MakerBot Industries LLC
         : Inventors assign to MakerBot
    2015 : Patent issued as US 9168698
    2022 : MakerBot assigns to Stratasys Inc

NPE / troll-pattern signals

Verdict

Operating-company assertion.

The chain is short and entirely first-party: inventors → MakerBot Industries, LLC (recorded 2013-12-30) → Stratasys, Inc. (recorded 2022-07-19), with no shell LLC, no aggregator, and no NPE anywhere. The current assignee, Stratasys, is a publicly traded 3D-printing manufacturer that (per the litigation section above) is asserting the '698 patent in its own name against genuine competitors in the Bambu Lab dispute — the textbook definition of an operating-company assertion rather than an NPE campaign. Every one of the eight troll signals is either "not present" or, for the single correspondent-recurrence signal, "unclear" solely because the reel/frame and correspondent fields could not be pulled this session.

Verification links: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ ; mirror — https://assignment.uspto.gov/patent/index.html ; Google Patents legal events — https://patents.google.com/patent/[US9168698B2](/patent/US9168698B2)/en .

Cross-reference flags / contradictions

• Consistent with the prior sections: the original assignee (MakerBot), current assignee (Stratasys), the 2022-07-19 reassignment, and prosecution counsel (Strategic Patents, P.C.) all match the Patent Summary and Litigation Summary already generated.
• Data gap, not a contradiction: the prior sections cited no reel/frame either; this section confirms that the assignment records exist and gives their recorded dates, but leaves reel/frame + recording correspondent open. If you need those three fields verified, they require a direct Assignment Center pull (or the USPTO assignment API) that was unavailable here.
• Date note carried forward: the Litigation Summary flagged that the prompt's internal date (April 2026) conflicted with the Sept. 17, 2026 verdict reports; nothing in the assignment chain depends on that, but the "pre-litigation transfer" signal was evaluated against the Aug. 2024 suit date.

I'll search for the prior-art citations listed on the '698 patent and the USPTO record.

Let me retrieve the patent's front-page "References Cited" list and USPTO full-text record.

I have the patent text but not its front-page "References Cited." Let me pull the IPR petition art and the cited references directly.

I hit the tool-step limit before I could retrieve the '698 patent's own front‑page "References Cited" list, and I will not fabricate it. Below is everything I can verify, with the gap flagged explicitly.

Prior-Art Analysis — U.S. Patent No. 9,168,698 ("Three‑Dimensional Printer With Force Detection")

⚠️ Critical scope limitation (read first)

Your task asks me to "look at each patent citation for 9168698" and map each to § 102. To do that faithfully I need the patent's "References Cited" (56) list — the U.S. patent documents, foreign documents, and non‑patent literature cited on the face of, or within, the '698 patent.

I was not able to retrieve that list in this session. The authoritative Google Patents text I was given
(https://patents.google.com/patent/[US9168698B2](/patent/US9168698B2)/en) includes the abstract, description, claims, classification, "Cited By (9)," and "Families Citing this family (276)" — but the fetched payload did not include the "Patent Citations" / "References Cited" table, and my follow‑up searches did not surface it. I therefore cannot enumerate the examiner‑cited references without inventing them, which I will not do.

Do not treat any reference below as having been "cited on" the '698 patent unless I explicitly say so.

1. What the "Cited By (9)" list actually is — and why it is NOT § 102 art

The nine references flagged on the '698 page are forward citations (later documents that cite '698). Every one has a priority date after the '698 priority date of Oct. 29, 2012. Under § 102(a)(2)/pre‑AIA § 102(e), a reference cannot anticipate a patent whose effective filing date precedes it. So none of these can anticipate any claim of '698 — claim 1 (the sole independent claim) or dependents 2–15.

(All dates/titles taken from the Google Patents "Cited By" table on the '698 page.)

Conclusion for this set: the closest thematic match is US 10,691,095 B2 (in‑situ diagnostics/control for material extrusion) — it is conceptually the same problem space as '698 claim 1, but it post‑dates '698's priority by ~3.5 years and therefore cannot be § 102 art. It is useful only as evidence of follow‑on development, not invalidity.

2. Family members — also not § 102 art here

The '698 family shares the Oct. 29, 2012 priority. Continuations/divisionals within that family (e.g., US 10,556,381, filed 2015‑10‑26, which claims the apparatus counterpart; US 10,994,462, "Planarizing build surfaces in three‑dimensional printing," from app. 16/784,889) are not prior art against '698 — they claim the same priority and are commonly owned/post‑AIA‑related. Flagged so they are not mistaken for § 102 references.

3. Where the real § 102/§ 103 art against '698 lives

The actual invalidity art asserted against '698 is in IPR2025‑00531, Shenzhen Tuozhu Technology Co., Ltd. et al. v. Stratasys, Inc. (Petitioner: Bambu Lab entities; Patent Owner: Stratasys), instituted Oct. 5–6, 2025. An instituted IPR petition must include the prior‑art references and exhibits relied on for § 102/§ 103. That petition (and its exhibit list) is the authoritative source for "the prior art for US 9168698" and is the correct place to build the reference‑by‑reference table you requested. I identified the proceeding from the Google Patents litigation tab and RPX/IPVerse records but could not retrieve the petition's exhibit list in this session, so I cannot map references to claims from it.

• RPX: https://litigation.rpxcorp.com/[ptab](/ptab)/18626-shenzhen-tuozhu-technology-v-stratasys-incorporated-ipr-of-698
• IPVerse (GreyB): https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2025-00531
• Google Patents litigation tab: https://patents.google.com/patent/US9168698/en

4. How to obtain the exact "References Cited" list (so this analysis can be completed)

None of these require me to guess:

1. USPTO PatentCenter → application 14/065,516 → "References Cited" / "PTAB" tabs.
2. Google Patents page → "Citations" section (distinct from "Cited By"); the page URL is in your source block.
3. Patent Public Search (ppubs.uspto.gov) → search 9168698 → "Front Page" view shows the (56) list.
4. IPR2025‑00531 petition (PTAB, Patent Trial and Appeal Board E2E / PTActs) → Ex. list = the § 102/§ 103 references actually at issue.

Once I have items 1–4, the deliverable you asked for (full citation + pub/filing date + brief description + potentially‑anticipated claims) can be produced exactly.

5. What I can say with confidence about claim structure (for later § 102 mapping)

When the citation list is available, the mapping should focus on claim 1, because it is the only independent claim; dependents 2–15 fall with it. Key elements an anticipating reference must disclose together:

• identifying build instructions;
• initiating a build on a printer with a fabrication tool and sensor(s) mechanically coupled to the tool configured to detect contact force between tool and a separate structure;
• detecting the contact force from a sensor signal; and
• creating a control signal to control a printer component in response to that force while depositing material during the build.

Dependent claim hooks to watch for in any asserted art: claim 3 (feed‑rate control), claim 4 (z‑distance control), claims 5–7 (compare to expected force → adjust or terminate), claims 10–11 (planarity detection + leveling layer), claim 12 (target contact force encoded in build instructions), claims 13–15 (strain gauge; piezoelectric; capacitive/optical/electromechanical/electromagnetic/acoustical).

6. Confidence & honesty notes

• High confidence: the nine "Cited By" references and their dates/assignees/titles (verbatim from the Google Patents table); that they all post‑date the '698 priority date; that they therefore cannot be § 102 art against '698.
• High confidence: the existence and institution status of IPR2025‑00531 as the venue for the actual invalidity art.
• Explicit non‑finding (do not paper over): I did not retrieve the '698 "References Cited" list, so I have not mapped any cited reference to any claim, and I have deliberately omitted any named pre‑2012 reference (e.g., foundational FDM/extrusion or force‑sensor art) because I could not confirm it appears on '698's face and listing it as "cited" would be fabrication. Any such candidates must be verified against items 1–4 above before use.
• Contradiction flag with the prior sections: my search summary and litigation summary already noted that no CAFC 2026 docket names 9168698; nothing in this prior‑art pass contradicts that. Also consistent: the Sept. 17, 2026 E.D. Tex. verdict and the earlier "current date April 26, 2026" discrepancy noted previously remains — reported as‑sourced, not resolved.

If you can supply the '698 front‑page (56) list or the IPR2025‑00531 exhibit list, I will produce the complete reference‑by‑reference § 102 table immediately.

I'll research the prior art landscape for this patent, including what the IPR2025-00531 petitioner asserted and the classic force-sensing references in material-extrusion printing.

I now have the actual IPR grounds. Let me confirm the identities and disclosures of the key references (Warren, Calderon, Napadensky, Eshed) and the printed publications cited on the patent's face.

Obviousness Analysis — U.S. Patent No. 9,168,698 under 35 U.S.C. § 103

Contradiction flags (per instruction)

Before the analysis, two explicit contradictions with the previously generated sections:

1. Date conflict. The task header sets the current date at April 26, 2026, but the earlier "Litigation summary" section describes a September 17, 2026 E.D. Tex. jury verdict and states an operating date of September 29, 2026. Under the April 26, 2026 date, that verdict has not yet occurred. I treat the Sept. 2026 verdict as not-yet-ripened here and do not rely on it. What is confirmed as of April 2026 is the institution of IPR2025-00531 (decision Oct. 5, 2025) — and the petition's grounds, which are the primary § 103 record below.
2. "Prior Art section" scope. The fetched Google Patents page's only dedicated prior-art fields are the metadata line Prior art keywords: contact force; build; dimensional printer; printer; extruder and Prior art date 2012-10-29. Its "Cited By (9)" and "Families Citing this family (276)" entries are later-dated documents (2015–2025) and therefore are not prior art against the '698 patent. I therefore ground this analysis in (a) the references of record on the family's face (Batchelder '141, Jang '872, Calderon '011, Lipson '198, Bonassar '003, plus the RepRap/HydraRaptor printed publications) and (b) the actual § 103 grounds asserted in IPR2025-00531, which I retrieved.

Effective date / law applied. Earliest priority is Oct. 29, 2012 (prov. 61/719,874); actual filing Oct. 29, 2013. The Board in IPR2025-00531 applied post-AIA § 103 because Patent Owner did not establish that the provisional supported the challenged claims (citing Dynamic Drinkware). Either way, every reference below predates Oct. 29, 2012, so it qualifies as prior art under § 102(a)(1)/(a)(2) (AIA) or § 102(b)/(e) (pre-AIA).

POSITA. A person having ordinary skill would have a B.S. in mechanical/electrical engineering (or equivalent) plus ~2–3 years' experience designing or operating material-extrusion/fused-deposition 3D printers, including the then-active open-source RepRap/MakerBot ecosystem, and would be familiar with off-the-shelf load cells and strain gauges.

Claim 1 — element map

The single genuinely narrowing idea is 1.d: closed-loop force feedback used in real time during deposition, not merely pre-build calibration. That is the pivot point for the whole obviousness question, because Calderon alone (pre-build Z-initialization) does not reach it, whereas Warren does.

Ground 1 — Claim 1 (and 2–6, 8–15) obvious over Warren, U.S. Pat. No. 6,986,739 B2

Reference: Warren, "Architecture Tool and Methods of Use," U.S. 6,986,739 B2 (granted Jan. 17, 2006; published as US 2003/0100824 A1, May 29, 2003). Retrieved: https://patentimages.storage.googleapis.com/7c/c9/cb/d9d880e140cd31/[US6986739](/patent/US6986739).pdf

Mapping. Warren discloses a "direct-write" material-dispensing tool with a vibro-sensoric dispenser 3700 that is mechanically instrumented:

• A vibration sensor 3730 / transducer 3740 "attached to the dispenser 3700" senses vibration modulated by contact with substrate 3710, producing "a feedback signal that is generally proportional to the intensity of the physical contact of the dispenser 3700 with the substrate 3710" (¶ [0302]), and the signal "is used to control the position of the dispenser 3700 to maintain a desired force of contact" — i.e., Warren expressly compares measured force to a desired force and varies position via a Z-controller, oscillator/amplifier/control circuitry and a motor (FIG. 22 flowchart: "DETECT CHANGE IN AMPLITUDE ΔA PROPORTIONAL TO CONTACT FORCE" → "CONTACT FORCE AS DESIRED?" → "VARY POSITION(S)").
• Warren's CAD/CAM system generates the part program → build instructions (1.a).
• Dispensing occurs while the position loop runs → "while depositing material during the build" (1.d).

Motivation to combine (Warren's own embodiments). Warren states the capillary dispensing unit is shown with the vibrating force sensor "by way of example only" and that "dispenser 3700 may be implemented differently" (¶¶ [0294], [0299]), and separately discloses a through-nozzle dispenser with a linear actuator providing an actuator-controlled "material dispensing rate" (¶¶ [0230]–[0252]). A POSITA would bolt the force-sensing loop onto the through-nozzle head to get both precise volumetric flow control and force feedback, thereby preventing tip/substrate damage. This is the classic KSR fact pattern (A: known elements combined by known methods for predictable results) and, because it is disclosed in one reference, is not even a true "combination of references"; the Federal Circuit permits combining disclosed embodiments of a single reference absent a teaching away.

Weakness to note. Warren is a biological/tissue-engineering direct-write system, not a thermoplastic FDM printer. Stratasys can argue non-analogous art or lack of reasonable expectation of success. Counter: same field of endeavor (computer-controlled deposition of a fluent material through a moving tip onto a substrate), and the '698 specification itself disclaims any narrowness by stating that "numerous additive fabrication techniques are known… all such printing technologies are intended to fall within the scope."

Ground 1B — Claims 3, 7, 9 obvious over Warren + Eshed

Reference: Eshed (EX1008), a patent publication describing a detection system that "generates signals responsive to unwanted protuberances that may be formed on a construction layer," noting that "as [the] shuttle [including printing head] moves over the construction layer it may collide with the protuberance and be damaged" (¶¶ [0171]–[0172]). I could not confirm the exact publication number in this session and do not guess at it.

Motivation. Warren itself acknowledges that an "improper prediction" of contact force "may result in either destruction of the dispenser or the substrate as the tip crashes into the substrate material" (¶ [0285]). A POSITA, confronted with that acknowledged failure mode, would look to Eshed's complementary teaching to terminate the build and output an error on collision. Legal rationales: KSR (C) known technique (shutdown-on-collision) applied to improve a similar device, and (D) applying a known technique to a device ready for improvement. Claims 3 (feed-rate component) and 9 (change extruder feed rate) follow because "stop production" entails stopping material feed; claim 7 (terminate on error) is met directly.

Ground 2A — Claim 1 (and 2–5, 7–10, 12–15) obvious over Calderon + RepRap20208

Calderon: U.S. 6,629,011 B1, Stratasys, "Autoinitialization in a three-dimensional modeling machine" (filed Jul. 17, 2000; issued Sept. 30, 2003). Retrieved: https://patentimages.storage.googleapis.com/db/1d/9f/b735edbe3307d9/[US6629011](/patent/US6629011).pdf. Calderon is of record on the '698 face (one of seven cited references), though Patent Owner stresses it "was never discussed on the merits."

• Discloses an extrusion-based modeling system 106 with a "sensor assembly… mounted to an extrusion head" sensing "the force of contact of the tip against the substrate" (5:10–24, 6:16–18), where the nozzle tip itself can serve as the "plunging means" to find Z (9:63–10:23).
• Expressly contemplates any sensing means, including tactile, capacitive, Hall, inductance, Wiegand wire, reed switch, and a vibrated plunger/transducer (6:37–61).
• Takes measurements at multiple x,y locations and compares recorded z-positions to determine whether the substrate top surface "is approximately parallel to an xy-plane," notifying the operator if not (claims 1, 14), and even senses an object under construction (claims 6, 15) — which maps to claims 10 (detect planarity) and the "separate structure = object being fabricated" concept.
• Generates a "file describing the geometry of a part 109" → build instructions.

RepRap20208: a 2009 RepRap community forum thread ("Genetic Algorithms"; posts by Wade/others), which states: "A strain gauge on the extruder mount would [show head collisions] as well, and it could do a few other things as well, like finding the bed height automatically… Collision detection is a nice side affect [sic] in addition to 'extruder height control'… a constant measurement of the force on the head (including its weight) would be useful."

Motivation. (i) Calderon's own suggested sensing path — "monitoring a change in the servo drive current" — suffers slop/backlash through the arm, x-y translator and drive motors, degrading the precision needed to know exactly when the tip touches; a strain gauge at the extruder mount measures closer to the point of contact and avoids that error. (ii) RepRap20208 supplies the real-time, during-build function Calderon lacks (collision detection while printing), yielding the 1.d limitation. (iii) Strain gauges were "common sensor[s]" — the '698 specification concedes this at 9:1–7 — making this a textbook KSR (B) simple substitution of a known element to obtain predictable results. Legal bottom line: predictable result; no change in the principle of operation of Calderon's printer; art-ready-for-improvement.

Gaps a challenger must close (and where Stratasys will fight):

• Public accessibility of RepRap20208. This is the single biggest vulnerability of Ground 2A. Stratasys argued (in its Request for Discretionary Denial) that the thread sits under "Home > General > Topic," is titled "Genetic Algorithms," and that Petitioner offered no "sufficiently definite roadmap" of indexing/searchability — the Blue Calypso / Acceleration Bay line of authority. If RepRap20208 is not a "printed publication," Ground 2A collapses to Calderon alone, which is pre-build calibration only.
• § 325(d) / Advanced Bionics. Calderon was cited on the '698 face; Stratasys argues the Office already considered it. Petitioner's counter — that Calderon was never discussed on the merits and that the examiner mistakenly believed the force-sensing sensor configuration was absent from the art — is the correct framing for a "material error" argument.
• Teaching away. Calderon arguably "discourages solutions that need 'special purpose sensing means'" (10:5–8), which Stratasys uses to attack the motivation to substitute a strain gauge. This is a factual dispute that cuts against a clean summary judgment of obviousness.

Ground 2B — Claim 11 obvious over Calderon + RepRap20208 + Napadensky

Reference: Napadensky (EX1005) — the petition cites a Napadensky 3D-printing patent disclosing a "leveling device 32" that "serves to straighten the newly formed layer prior to the formation of the successive layer thereon" (17:56–18:47), in the context of collisions caused by "dispensed layers being too thick and/or inconsistent in thickness" or "material spill or faulty material dispensing" (18:5–18). The column cites align with the Napadensky/Cubital leveling-dispatcher family (the reference uses "leveling device 32," "tray 12," "axis 14"); I did not independently confirm the exact patent number and therefore do not state one. The petition's expert observed this is "similar to the description of the '698 patent" at FIG. 5, where dent 502 is filled to form layer 504 (10:20–27).

Motivation. Leveling the newly formed layer reduces the surface irregularities that cause collisions — i.e., it is a complementary fix for exactly the failure mode RepRap20208's collision detection only detects. Predictable improvement; KSR (A)/(C). This maps to claim 11 ("fabricating a layer on the surface… that decreases one or more irregularities").

Weakness. Claim 11 in the '698 patent derives from contact-force-derived planarity detection plus proportional material deposition based on deviation from maximum measured force, whereas Napadensky's "leveling device 32" appears to be a mechanical squeegee/roller leveling a dispensed layer — a different mechanism. Stratasys will argue the prior art levels by a different physical approach; but under KSR a different mechanism reaching the same predictable result does not defeat obviousness, and claim 11's own language ("fabricating a layer… that decreases one or more irregularities") does not require the roller-free, force-proportional deposition described only in the specification.

Independent (non-petition) obviousness theories I would also develop

1. The RepRap / HydraRaptor printed publications of record on the '381 family face, which independently establish that force/probe-based bed leveling and Z-probing were known before Oct. 2012: "Touch Sensor and Automated Calibration," by Assargadon, RepRap forums (Jan. 4, 2008) and "HydraRaptor" auto-Z-probe (Apr. 4, 2011). These are the strongest independent attack on claims 10 and 11 and support a Calderon + these publications combination without relying on RepRap20208's accessibility.
2. Warren + the RepRap publications for a belt-and-suspenders attack on claim 1: Warren supplies the force-controlled dispenser loop; the RepRap art supplies the strain gauge on an extruder mount and during-print collision detection. Because Warren is not on the face of the '698 patent, this combination also moots Stratasys's § 325(d) argument.
3. Sensor-type claims 13–15. These should be the easiest to invalidate: Warren teaches a piezoelectric bimorph ("piezoelements, piezomembranes, and piezotransducers") and a fiber-optic (optical) sensor (¶¶ [0297], [0300]); Calderon enumerates capacitive, Hall/electromagnetic, inductance, reed-switch and pneumatic sensors (6:37–61). Electromechanical and acoustical sensors are the residue, and selecting among known force-sensing transducers is "obvious to try" (KSR (E)) — with the added admission in the '698 spec that strain gauges are "one common sensor."
4. Claim 12 (build instruction specifying a target contact force). Warren's FIG. 22 control flow ("CONTACT FORCE AS DESIRED?" → vary position) is a target-force closed loop; encoding that target in the part program is an obvious implementation choice, especially against the background of G-code/M-code machine-ready instructions the POSITA would have known.

Summary table

Bottom line

Under § 103, claim 1 is most cleanly obvious over Warren alone, and is independently obvious over Calderon in view of RepRap20208 if RepRap20208's public accessibility is sustained. The dependent claims covering feed-rate and z-distance control, force comparison and build termination (3–9) fall easily with Eshed as a secondary reference; the planarity/leveling claims (10–11) are the most defensible because they combine multi-point force mapping with a material-deposition (as opposed to mechanical-roller) leveling step, and that is precisely where Napadensky is a weaker fit; the sensor-type claims (13–15) are the least defensible.

The two biggest open questions for a final validity call are therefore (i) whether RepRap20208 qualifies as a printed publication, and (ii) whether the "while depositing material during the build" nuance of claim 1 defeats Calderon-plus-strain-gauge on its own. Note that the district court jury's validity finding reported in the earlier section (if and when it ripens) is not dispositive of § 103 in the PTAB, and vice versa — and, per the contradiction flag above, that verdict postdates the operative date of this analysis.