Prosecution Insights
Last updated: April 19, 2026
Application No. 17/923,035

LAYER SYSTEM, FLOW FIELD PLATE HAVING A LAYER SYSTEM OF THIS TYPE, AND FUEL CELL, ELECTROLYZER OR REDOX FLOW CELL

Final Rejection §103
Filed
Feb 16, 2023
Examiner
DARBY, BRENDON CHARLES
Art Unit
1749
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Schaeffler Technologies AG & Co. Kg
OA Round
2 (Final)
51%
Grant Probability
Moderate
3-4
OA Rounds
2y 9m
To Grant
67%
With Interview

Examiner Intelligence

Grants 51% of resolved cases
51%
Career Allow Rate
61 granted / 120 resolved
-14.2% vs TC avg
Strong +16% interview lift
Without
With
+16.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
46 currently pending
Career history
166
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
54.2%
+14.2% vs TC avg
§102
18.2%
-21.8% vs TC avg
§112
24.4%
-15.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 120 resolved cases

Office Action

§103
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This action is in response to applicant’s amendments and arguments filed 11/07/2025. Claims 1-12 are currently pending for examination on the merits. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1-12 are rejected under 35 U.S.C. 103 as being unpatentable over Dobrenizki et al. (US 2019/0051913) (Dobrenizki) (of record) in view of Tarutani (US 2018/0053948) (of record). Regarding claim 1, Dobrenizki discloses a layer system for coating a metal substrate to form a flow field plate (title; abstract; [0067]) comprising: at least one cover layer (3a) made of metal nitride, at least one intermediate layer (4b) supporting the cover layer (3a), and a lower layer (4a) supporting the intermediate layer (4b) (see Figure; [0075]), wherein the at least one intermediate layer (4b) is formed from titanium nitride ([0077]), and wherein the lower layer (4a) is formed from titanium ([0077]). Dobrenizki fails to disclose, however, that the cover layer (3a) is formed from indium tin oxide, wherein the indium tin oxide is doped with at least one element from a group comprising carbon, nitrogen, boron, fluorine, hydrogen, silicon, titanium, tin, and zirconium. However, it is known in the art to provide flow field plates with an indium tin oxide cover layer. For instance, Tarutani teaches a flow field plate (separator/bipolar plate) (title; abstract; [0001]) that is provided with an ITO (indium tin oxide) outer cover layer ([0048]-[0050]; [0204]-[0205]; [0231]). Examiner also notes that ITO is necessarily doped with tin ([0048]; [0205]; [0231]). Tarutani further teaches that this ITO cover layer enhances the surface contact resistance performance of the flow field plate, improves its conductivity, and enhances its durability ([0043]; [0045]-[0046]; [0050]; [0164]; [0200]; [0202]; [0205]). Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have substituted the cover layer disclosed by Dobrenizki with the ITO cover layer taught by Tarutani because they would have had a reasonable expectation that doing so would improve the surface contact resistance performance of the flow field plate, improve its conductivity, and enhance its durability. Regarding claim 2, modified Dobrenizki discloses all of the limitations as set forth above for claim 1. Tarutani further teaches that the ITO cover layer can have an indium oxide content of 90 mass% and a tin oxide content of 10 mass% (Tarutani: [0205]; [0231]; [0244]). Given that the density of indium is about 7.31 g/cm3, and the density of tin oxide is about 6.95 g/cm3, the volume ratio of indium to tin oxide can be calculated to be 8.56:1 ((90/7.31)/(10/6.95)), which leads to an indium oxide volume content of about 89%, suggesting the claimed range of 70 to 90 vol%. Therefore, since modified Dobrenizki includes the teachings from Tarutani regarding the ITO cover layer, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention for modified Dobrenizki to have satisfied all of the limitations in claim 2. Regarding claim 3, modified Dobrenizki discloses all of the limitations as set forth above for claim 1. Modified Dobrenizki further discloses that the lower layer (Dobrenizki: 4a) can have a layer thickness of 100 nm (Dobrenizki: [0078]), suggesting the claimed range of 1 to 300 nm. Regarding claim 4, modified Dobrenizki discloses all of the limitations as set forth above for claim 1. Modified Dobrenizki further discloses that the at least one intermediate layer (Dobrenizki: 4b) can have a layer thickness of 100 nm (Dobrenizki: [0078]), which is equal to 0.1 µm, suggesting the claimed range of 0.1 µm to 3.0 µm. Regarding claim 5, modified Dobrenizki discloses all of the limitations as set forth above for claim 1. Modified Dobrenizki further discloses that the cover layer (Dobrenizki: 3a) can have a layer thickness of 100 nm (Dobrenizki: [0081]), which is equal to 0.1 µm, suggesting the claimed range of 0.01 µm to 15 µm. Furthermore, Tarutani teaches that the cover layer can have a layer thickness of 0.5 µm (Tarutani: [0244]), which also suggests the claimed range of 0.01 µm to 15 µm. Regarding claims 6 and 11, modified Dobrenizki discloses all of the limitations as set forth above for claim 1. As set forth above, Tarutani teaches that the cover layer is formed from ITO, which is necessarily doped with tin. Tarutani further teaches that the ITO cover layer can have an indium oxide content of 90 mass% and a tin oxide content of 10 mass% (Tarutani: [0205]; [0231]; [0244]). Given these values, the molar mass of 277.64 g/mol for indium oxide (In2O3), and the molar mass of 150.71 g/mol for tin oxide (SnO2), the total amount of moles of indium oxide in 100 g of the ITO compound is equal to 0.324 (90/277.64), and the total amount of moles of tin oxide in 100 g of the ITO compound is equal to 0.066 (10/150.71). This leads to a total amount of moles of indium equal to 0.648 (0.324*2), a total amount of moles of oxygen equal to 1.104 ((0.324*3)+(0.066*2)), and a total amount of moles of tin equal to 0.066 (0.066*1). Thus, an atomic percentage of tin in the compound can be calculated to be about 3.63% ((0.066/(0.648+1.104+0.066))*100), suggesting the claimed ranges of at most 35 at% and from 0.1 to 10 at%. Therefore, since modified Dobrenizki includes the teachings from Tarutani regarding the cover layer, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention for modified Dobrenizki to have satisfied all of the limitations in claims 6 and 11. Regarding claim 7, modified Dobrenizki discloses a flow field plate (Dobrenizki: 1) comprising a metal substrate (Dobrenizki: 2) and a layer system (Dobrenizki: 3) according to claim 1 (Dobrenizki: see Figure; [0075]), having a structure of the flow field plate (Dobrenizki: 1) in the order of: metal substrate (Dobrenizki: 3), lower layer (Dobrenizki: 4a), intermediate layer (Dobrenizki: 4b), and cover layer (Dobrenizki: 3a) (see Figure; [0075]). Regarding claim 8, modified Dobrenizki disclose all of the limitations as set forth above for claim 7. Modified Dobrenizki further discloses that the metal substate (Dobrenizki: 2) is formed from steel (Dobrenizki: [0075]). Regarding claim 9, modified Dobrenizki discloses a fuel cell comprising at least one flow field plate (Dobrenizki: 1) according to claim 7 (title; [0076]-[0077]). Regarding claim 10, modified Dobrenizki discloses all of the limitations as set forth above for claim 9. Modified Dobrenizki further discloses that the fuel cell is a polymer electrolyte fuel cell ([0076]), which necessarily includes at least one polymer electrolyte membrane ([0009]). Regarding claim 12, modified Dobrenizki discloses all of the limitations as set forth above for claim 9. Modified Dobrenizki further discloses that the fuel cell can be an electrolyzer (abstract; [0022]). Response to Arguments Applicant’s amendments to the specification and claims have overcome each and every objection and 112(b) rejection previously set forth in the Non-Final Office Action mailed 08/11/2025. Applicant’s arguments with respect to amended independent claim 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. As such, claims 1-12 stand rejected. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRENDON C DARBY whose telephone number is (571)272-1225. The examiner can normally be reached Monday - Friday: 7:30am - 5:00pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Katelyn Smith can be reached at (571) 270-5545. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /B.C.D./Examiner, Art Unit 1749 /KATELYN W SMITH/Supervisory Patent Examiner, Art Unit 1749
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Prosecution Timeline

Feb 16, 2023
Application Filed
Aug 07, 2025
Non-Final Rejection — §103
Nov 07, 2025
Response Filed
Feb 24, 2026
Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
51%
Grant Probability
67%
With Interview (+16.0%)
2y 9m
Median Time to Grant
Moderate
PTA Risk
Based on 120 resolved cases by this examiner. Grant probability derived from career allow rate.

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