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 .
Response to Amendment
In response to the amendment received on 05/13/2026:
Claims 1, 3-4, 6-11, 13, and 15-24 are pending in the current application. Claims 1, 6, and 9 have been amended. Claims 21-24 have been newly added.
The previous prior art-based rejection have been withdrawn.
Response to Arguments
Applicant’s arguments, see Remarks Page 8, filed 05/13/2026, with respect to the objections to the drawings have been fully considered. The objections have been withdrawn in light of the replacement drawings.
Applicant’s arguments, see Remarks Page 9, filed 05/13/2026, with respect to the objections to the specification have been fully considered. The objections have been withdrawn in light of the amendments to the specification.
Applicant’s arguments, see Remarks Page 9, filed 05/13/2026, with respect to the objections to the claims have been fully considered. The objections have been withdrawn in light of the amendments to the claims.
Applicant’s arguments, see Remarks Pages 8-12, filed 05/13/2026, with respect to the rejections under 35 U.S.C. 103 have been fully considered. The rejections have been withdrawn in light of the amendments to the claims.
Election/Restrictions
Claims 1, 3-4, and 6-10 are directed to an allowable product. Pursuant to the procedures set forth in MPEP § 821.04(B), claims 11, 13, and 15-20, directed to the process of making or using an allowable product, previously withdrawn from consideration as a result of a restriction requirement, are hereby rejoined and fully examined for patentability under 37 CFR 1.104.
Because all claims previously withdrawn from consideration under 37 CFR 1.142 have been rejoined, the restriction requirement as set forth in the Office action mailed on 02/04/2026 is hereby withdrawn. In view of the withdrawal of the restriction requirement as to the rejoined inventions, applicant(s) are advised that if any claim presented in a divisional application is anticipated by, or includes all the limitations of, a claim that is allowable in the present application, such claim may be subject to provisional statutory and/or nonstatutory double patenting rejections over the claims of the instant application. Once the restriction requirement is withdrawn, the provisions of 35 U.S.C. 121 are no longer applicable. See In re Ziegler, 443 F.2d 1211, 1215, 170 USPQ 129, 131-32 (CCPA 1971). See also MPEP § 804.01.
Claim Objections
Claims 1 and 21 are objected to because of the following informalities:
There should be a hyphen between the words “in” and “between”.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 3 and 13 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 3, the claim recites “wherein the first anode flow field configuration is a mixed flow configuration and the second anode flow field configuration is a parallel flow configuration”.
Claim 3 depends from claim 1 which recites “wherein the first anode flow field configuration is an interdigitated flow configuration, and the second anode flow field configuration is a parallel flow configuration”.
Applicant’s specification states:
“ [0025] FIG. 5B illustrates a fuel cell including a composite anode flow field, the composite anode flow field may include an interdigitated flow field and a parallel flow field;
[0026] FIG. 5C illustrates a fuel cell including a composite anode flow field, the composite anode flow field may include a mixed flow field and a parallel flow field”.
Therefore, it is set forth in Applicant’s specification that an interdigitated flow field and a mixed flow field are different flow field configurations.
Given claim 1 already recites wherein the first anode flow field configuration is an interdigitated flow configuration, it is unclear how the configuration of the first anode flow field could also be a mixed flow configuration.
Regarding claim 13, the claim recites “wherein the first anode flow field configuration is a mixed flow configuration and the second anode flow field configuration is a parallel flow configuration”.
Claim 13 depends from claim 11 which recites “wherein the first anode flow field configuration is an interdigitated flow configuration, and the second anode flow field configuration is a parallel flow configuration”.
Applicant’s specification states:
“ [0025] FIG. 5B illustrates a fuel cell including a composite anode flow field, the composite anode flow field may include an interdigitated flow field and a parallel flow field;
[0026] FIG. 5C illustrates a fuel cell including a composite anode flow field, the composite anode flow field may include a mixed flow field and a parallel flow field”.
Therefore, it is set forth in Applicant’s specification that an interdigitated flow field and a mixed flow field are different flow field configurations.
Given claim 11 already recites wherein the first anode flow field configuration is an interdigitated flow configuration, it is unclear how the configuration of the first anode flow field could also be a mixed flow configuration.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 22 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 22 recites “wherein the first anode flow field configuration is a mixed flow configuration and the second anode flow field configuration is a parallel flow configuration”.
Claim 22 depends from claim 21 which already recites “wherein the first anode flow field configuration is a mixed flow configuration, and the second anode flow field configuration is a parallel flow configuration”.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Allowable Subject Matter
If the claim objections are overcome, then claims 1, 4, 6-11, 15-21, and 23-24 would be allowed.
Independent claim 1 recites “A fuel cell system comprising a fuel cell including: an anode and a cathode, a membrane electrode assembly on a first side of an anode gas diffusion layer, a bipolar plate on a second side of the anode gas diffusion layer comprising an anode flow field, and a microporous layer in between the membrane electrode assembly and the anode gas diffusion layer, wherein the anode flow field comprises at least a first anode flow field configuration and a second anode flow field configuration, and wherein hydrogen flows through the first anode flow field configuration and the second anode flow field configuration of the anode flow fields, wherein the first anode flow field configuration is an interdigitated flow configuration, and the second anode flow field configuration is a parallel flow configuration, and wherein the anode gas diffusion layer comprises a first anode gas diffusion layer corresponding to the first anode flow field configuration and a second anode gas diffusion layer corresponding to the second anode flow field configuration, and wherein the first anode gas diffusion layer is hydrophilic and the second anode gas diffusion layer is hydrophobic”.
Independent claim 11 recites “A method of operating a fuel cell system including a fuel cell stack comprising: operating a plurality of fuel cells comprising a membrane electrode assembly on a first side of an anode gas diffusion layer and a bipolar plate on a second side of the anode gas diffusion layer, wherein the anode gas diffusion layer comprises a first anode flow field configuration and a second anode flow field configuration, flowing hydrogen through the first anode flow field configuration and the second anode flow field configuration, increasing efficiency of the fuel cell system by decreasing water accumulation in the fuel cell stack, wherein the first anode flow field configuration is an interdigitated flow configuration, and the second anode flow field configuration is a parallel flow configuration, and wherein the anode gas diffusion layer comprises a first anode gas diffusion layer corresponding to the first anode flow field configuration and a second anode gas diffusion layer corresponding to the second anode flow field configuration, and wherein the first anode gas diffusion layer is hydrophilic and the second anode gas diffusion layer is hydrophobic”.
Independent claim 21 recites “A fuel cell system comprising a fuel cell including: an anode and a cathode, a membrane electrode assembly on a first side of an anode gas diffusion layer, a bipolar plate on a second side of the anode gas diffusion layer comprising an anode flow field, and a microporous layer in between the membrane electrode assembly and the anode gas diffusion layer, wherein the anode flow field comprises at least a first anode flow field configuration and a second anode flow field configuration, and wherein hydrogen flows through the first anode flow field configuration and the second anode flow field configuration of the anode flow fields, wherein the first anode flow field configuration is a mixed flow configuration, and the second anode flow field configuration is a parallel flow configuration, and wherein the anode gas diffusion layer comprises a first anode gas diffusion layer corresponding to the first anode flow field configuration and a second anode gas diffusion layer corresponding to the second anode flow field configuration, and wherein the first anode gas diffusion layer is hydrophilic and the second anode gas diffusion layer is hydrophobic”.
Previously cited Modified Tighe (see Non-Final Rejection dated 04/17/2026 Pages 5-6) and previously cited modified Noh (see Non-Final Rejection dated 04/17/2026 Pages 6-8) both include an anode gas diffusion layer, a first anode flow field configuration that is an interdigitated flow configuration, and a second anode flow field configuration that is a parallel flow configuration. However, neither of them teach wherein the gas diffusion layer includes a hydrophilic first anode gas diffusion layer corresponding to the interdigitated first anode flow field configuration or a hydrophobic second anode gas diffusion layer corresponding to the parallel second anode flow field configuration.
Further search revealed Darling et al (US 20140302423 A1) which teaches a flow battery utilizing a “mixed flow” flow field to provide a beneficial balance between pressure drop and performance (P21).
Even further search revealed Perry et al (US 6485857 B2) which teaches an anode flow field including a mixed flow configuration and a parallel configuration (see Fig. 4; C4 / L57 – C5 / L39).
Previously cited Kourtakis (see Non-Final Rejection dated 04/17/2026 Page 16) which teaches gas diffusion backing for a proton exchange membrane fuel cell can optionally be treated to exhibit hydrophilic or hydrophobic behavior (P35).
Previously cited Lim (see Non-Final Rejection dated 04/17/2026 Page 16) states “Kitahara et al. [12,13] made hydrophilic and hydrophobic double MPL coated GDL and performed the optimization of the GDL under various humidity conditions… Shrestha et al. [18] coated a hydrophilic microporous layer to a commercial hydrophobic bi- layer GDL. PEMFC with the modified GDL decreased the ohmic resistance without anode humidification but increased mass transport resistance at high current densities… Guo et al. [20] made GDL with hydro phobic and hydrophilic synergistic surfaces using an ultrasonic atomizing hydrophilic reagent, and the GDL improved the PEMFC peak power due to its enhanced water management” (Page 1 Right Column to Page 2 Left Column). Lim stated their experiments included a reference gas diffusion layer (GDL) modified by deposition of HfO2 on the microporous layer (MPL) using atomic layer deposition (ALD) (Abstract, Page 2 Right Column).
However, none of the prior arts above specify that a hydrophilic section of a gas diffusion layer should correspond to a section of a bipolar plate having an interdigitated flow configuration or mixed flow configuration while a hydrophobic section of a gas diffusion layer should correspond to a section of a bipolar plate having a parallel flow design.
Conclusion
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/MARY GRACE HARRIS/Examiner, Art Unit 1729
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