Prosecution Insights
Last updated: April 19, 2026
Application No. 17/938,679

NON-MEMBRANE DEIONIZATION AND ION-CONCENTRATING APPARATUS AND NON-MEMBRANE DEIONIZATION AND ION-CONCENTRATING MODULE

Final Rejection §103
Filed
Oct 07, 2022
Examiner
WITTENBERG, STEFANIE S
Art Unit
1795
Tech Center
1700 — Chemical & Materials Engineering
Assignee
National Tsing Hua University
OA Round
4 (Final)
54%
Grant Probability
Moderate
5-6
OA Rounds
3y 2m
To Grant
73%
With Interview

Examiner Intelligence

Grants 54% of resolved cases
54%
Career Allow Rate
361 granted / 667 resolved
-10.9% vs TC avg
Strong +19% interview lift
Without
With
+19.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
59 currently pending
Career history
726
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
51.2%
+11.2% vs TC avg
§102
17.6%
-22.4% vs TC avg
§112
29.2%
-10.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 667 resolved cases

Office Action

§103
DETAILED ACTION Status of Claims Claims 1-12 are pending. 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 . Status of Objections and Rejections The previous grounds of rejection stand. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. 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. Claim(s) 1-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tan et al. (“Pseudocapacitive behaviors of polypyrrole grafted activated carbon and MnO2 electrodes to enable fast and efficient membrane-free capacitive deionization”, Environmental Science & Technology, 2020, 54, 5843-5852) in view of Tang et al. (“Various cell architectures of capacitive deionization: Recent advances and future trends”, Water Research, 150, 2019, 225-251). Regarding claim 1, Tan discloses a membrane free capacitive deionization (title) (= a non-membrane deionization and ion-concentrating apparatus connected to a power supply) comprising: Opening between electrodes with a distance less than 500 microns (= a microfluidic channel, wherein the microfluidic channel is a micrometer-sized structure) (pg. 5849, right column, first paragraph, Figure S2); Carbon paper (pg 5844, right column, 2.1 Preparation and Characterizations of AC, Ppy/AC, and MnO2 electrodes) (= two current collectors, wherein the microfluidic channel is disposed between the two current collectors, and the power supply applies a voltage to the two current collectors); and A polypyrrole grafted activated carbon (Ppy/AC) electrode and MnO2 electrode on the carbon paper connected to a potentiostat (abstract, pg. 5845, left column, second paragraph) (= an electroactive material coated and connected to at least one of the two current collectors, wherein the electroactive material has a reversible redox ability, and the electroactive material is a pseudo-capacitive material or a battery material; the instant specification indicates that MnO2 for example is an electroactive material). Tan differs from the instant claim in that Tan fails to disclose the microfluid channel as a serpentine flow pattern. In the same or similar field of capacitive deionization (CDI) devices, Tang discloses capacitive deionization devices comprising Faradaic interactions, flow-through CDI devices, and flow-electrode devices etc. (abstract). In flow-electrode CDI, Tang discloses that CDIs can have various channel shapes including serpentine channels carved in a current collector. Tang discloses that when an electrical voltage is applied between the current collectors of an FDCI cell, ions present in the feed water would enter the flow electrode. A serpentine shaped channel is depicted in Figure 12a. Tang teaches that the flow electrode cell design provides improved performance (pg. 239, 2.4 Flow-electrode capacitive deionization). Tang teaches that various cell architectures demonstrate unique features and functionalities and achieve remarkable advancements in the field of CDI (pg. 246, 4. Perspectives and outlook). Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to produce a system comprising a serpentine flow pattern because Tang discloses that various architectures including a flow electrode with a serpentine flow channel provide improved CDI devices. It would have been obvious to modify the device of Tan with a serpentine flow channel of the current collectors of Tang for producing an apparatus with improved performance. It is noted that the clamed “non-membrane” deionization… is only within the preamble. The body of the claim does not provide further subject matter regarding a non-membrane. It is also noted that “deionization and ion-concentrating” in the preamble is not further limiting to the body of the claim. Regarding claim 2, Tang discloses flow channels within the micron range (microporous, pg. 235-237; microporosity pg. 238). A microfluidic channel of 1 to 300 microns would have been an obvious engineering design choice in order to achieve the performance improvements disclosed by Tang. Regarding claim 3, Tan discloses loading of 16 mg and 15 mg for a 3 cm x 2 cm working area which equates to approximately 2-3 mg/cm2 which falls within the claimed range (pg 5844, right column, 2.1 Preparation and Characterizations of AC, Ppy/AC, and MnO2 electrodes). Regarding claim 4, Tan discloses activated carbon (= electrical double layer electrode material) coated with MnO2 (= electroactive material). Regarding claims 5-6, Tan discloses activated carbon/polypyrrole (= organic electrode material) and MnO2 (= transition metal oxide). Since Tan discloses both charging and discharging of the cell the designation of a positive electrode or negative electrode applies to either electrode (pg 5845, left column, second paragraph). Regarding claim 7, Tan discloses the cell for being selective for sodium for example (abstract). Regarding claim 8, Tan discloses the cell is membrane free (title). Claim(s) 9-12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tan et al. (“Pseudocapacitive behaviors of polypyrrole grafted activated carbon and MnO2 electrodes to enable fast and efficient membrane-free capacitive deionization”, Environmental Science & Technology, 2020, 54, 5843-5852), in view of Tang et al. (“Various cell architectures of capacitive deionization: Recent advances and future trends”, Water Research, 150, 2019, 225-251) and in further view of Dutta et al. (US 2020/0180982). Regarding claims 9-12, Tan in view of Tang does not disclose the cell within a module as claimed. In the same or similar field of endeavor, Dutta discloses a desalination device that may have a plurality of units arranged in series and/or parallel configuration to increase capacity, flexibility, security or the redundance in the system [0116]. Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to produce the capacitive deionization device of Tan in view of Tang as a module with multiple cells because Dutta discloses a desalination device that may have a plurality of units arranged in series and/or parallel configuration to increase capacity, flexibility, security or the redundance in the system [0116]. Response to Arguments Applicant's arguments filed 11 September 2025 have been fully considered but they are not persuasive. On page 7 of the remarks, the argument states that D1 (Tan et al.) discloses a cavity and not a channel. The Examiner respectfully disagrees with this analysis. Initially it is noted that a cavity is a hole or hollow and therefore reasonably would read on channel. Further, Tan et al. disclose a device including a channel (pg. 5845, left column, first paragraph, Fig. S2) of gasket(s) or spacer and/or channel created by opposing electrodes (abstract Figure). On page 8 the argument states that D2 (Tang et al.) fails to disclose a non-membrane deionization and ion-concentrating apparatus and therefore does not disclose the claimed apparatus. The Examiner respectfully disagrees with this analysis. As indicated by the title of Tang et al., the disclosure is directed towards trends and well-known devices in the capacitive deionization subject matter area. Tang et al. is inclusive of both membrane and membrane-free devices (page 240, right column, “membrane-free ECDI”). Tang et al. unambiguously discloses serpentines channels. Similar to Tan et al., Tang is inclusive of end plate current collectors and gaskets comprising serpentine flow channels (Figure 12a, Tang et al.). Although a membrane is present in Figure 12a of Tang et al., the teaching of a similar device without the membrane is clearly disclosed by the teachings of both Tan et al. and Tang et al. On page 9 the argument states that the cavity of D1 cannot restrict the direction of the feeding flow. The Examiner respectfully disagrees with this analysis. It is noted that the claimed microchannel is not of the current collector or electroactive material of Tan et al. According to the instant specification the microchannel (110) is present between the electroactive material (130) (Figures 1-2). Similarly to the instant specification, Tan et al. disclose a gasket and/or spacer between the electrode and/or endplate (Figure S2). Additionally, Tang et al. disclose the flow channel of the gasket material between the end plate current collectors. Therefore, the construction or design of the combination appears to be the same or similar to that of the instant specification. Thus, a resistance time or control of composition of ions would be expected to be the same or similar as the claimed invention. Conclusion THIS ACTION IS MADE FINAL. 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 STEFANIE S WITTENBERG whose telephone number is (571)270-7594. The examiner can normally be reached Monday - Friday, 7:00 am -4:00 pm EST. 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, Luan Van can be reached at (571) 272-8521. 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. /Stefanie S Wittenberg/Primary Examiner, Art Unit 1795
Read full office action

Prosecution Timeline

Oct 07, 2022
Application Filed
Sep 25, 2024
Non-Final Rejection — §103
Dec 17, 2024
Response Filed
Mar 12, 2025
Final Rejection — §103
May 15, 2025
Request for Continued Examination
May 16, 2025
Response after Non-Final Action
Jun 10, 2025
Non-Final Rejection — §103
Sep 11, 2025
Response Filed
Dec 31, 2025
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

5-6
Expected OA Rounds
54%
Grant Probability
73%
With Interview (+19.3%)
3y 2m
Median Time to Grant
High
PTA Risk
Based on 667 resolved cases by this examiner. Grant probability derived from career allow rate.

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