Prosecution Insights
Last updated: April 19, 2026
Application No. 18/415,604

Ultra-Sensitive Tin Oxide Sensor for Room Temperature Detection of Oxidizing and Reducing Gases

Non-Final OA §103
Filed
Jan 17, 2024
Examiner
GRAVES, TIMOTHY P
Art Unit
2855
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
UNIVERSITY OF PUERTO RICO
OA Round
1 (Non-Final)
81%
Grant Probability
Favorable
1-2
OA Rounds
2y 8m
To Grant
97%
With Interview

Examiner Intelligence

Grants 81% — above average
81%
Career Allow Rate
363 granted / 449 resolved
+12.8% vs TC avg
Strong +16% interview lift
Without
With
+15.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
20 currently pending
Career history
469
Total Applications
across all art units

Statute-Specific Performance

§101
3.9%
-36.1% vs TC avg
§103
40.2%
+0.2% vs TC avg
§102
22.7%
-17.3% vs TC avg
§112
26.1%
-13.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 449 resolved cases

Office Action

§103
Ultra-Sensitive Tin Oxide Sensor for Room Temperature Detection of Oxidizing and Reducing Gases 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 . Drawings The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the metal oxide nanoshell deposited on the polymer fiber substrate must be depicted, and the method steps must be shown or the features canceled from the claims. No new matter should be entered. Further, figures 1A-1C are not of sufficient quality to permit examination. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance. 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 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. Claims 1-2 are rejected under 35 U.S.C. 103 as being unpatentable over Wu (MDPI, "High-sensitive ammonia sensors based on tin monoxide nanoshells,2019; "Wu"), in view of Evanghelidis (RO 129633; "Evanghelidis"). Regarding claim 1, Wu discloses a gas sensor for detecting a gas (TITLE, “high-sensitive ammonia sensors”), the gas sensor comprising: a substrate (p. 3, ¶ 4, Wu’s sensors are welded on substrates); a metal oxide nanoshell (see p. 3, eq. 2, examiner notes Wu synthesizes SnO nanoshells) disposed on the polymer substrate (see previous comment). The Examiner notes that the limitation, “wherein the metal oxide nanoshell is deposited on the polymer fiber substrate by magnetron sputtering deposition” is a product-by-process type limitation. Applicant is reminded that features must be distinguished from the prior art by structure rather than by process. In the instant case, the process of depositing the nanoshells on the substrate produces a structure that is anticipated by Wu. See MPEP 2113. Wu fails to disclose the type of substrate. Evanghelidis teaches a metal oxide (see Evanghelidis’ translation, p. 3, ¶ 7, “nanostructed zinc oxide layer”) disposed on the polymer substrate (see Evanghelidis’ translation, p. 3, ¶ 7, “polymeric fiber networks”). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate Evanghelidis’ scheme of depositing the metal oxide on to a polymer substrate as Wu’s process for fabricating the sensor assemblies since it is well known to combine prior art elements according to known methods to yield predictable results. Doing so provides a reliable way of supporting the metal oxide nanoshells. Regarding claim 2, Wu and Evanghelidis disclose the metal oxide is tin oxide (Wu, ABSTRACT, “high-sensitive ammonia sensors based on self-assembly SnO nanoshells”). Claims 3 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Wu (MDPI, "High-sensitive ammonia sensors based on tin monoxide nanoshells,2019; "Wu") and Evanghelidis (RO 129633; "Evanghelidis"), as applied to 2, in view of Drmoshi (US 20190369040; "Drmoshi"). Regarding claim 3, Wu and Evanghelidis disclose the gas sensor (Wu, ABSTRACT, “high-sensitive ammonia sensors”). Examiner notes that the limitation: “for detecting NO2” is an intended use type statement. Applicant is reminded that a claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. See MPEP 2114. Wu and Evanghelidis fail to explicitly disclose the gas sensor is also for detecting NO2. Drmoshi teaches the gas sensor is also for detecting NO2. (ABSTRACT, “room temperature nitrogen dioxide gas sensor comprising tin(IV) oxide decorated with gold nanoparticles is described”) It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use Drmoshi’s design of a Nitrogen Dioxide gas sensor comprising sputtered tin oxide to teach Wu and Evanghelidis to detect nitrogen dioxide. Doing so increases the application of the sensors. Regarding claim 5, Wu and Evanghelidis disclose, the polymer fiber substrate (Wu, p. 3, ¶ 4, Wu’s sensors are welded on substrates, also see Evanghelidis’ translation, p. 3, ¶ 7, “polymeric fiber networks”) is prepared by electrospinning (see Evanghelidis’ translation, p. 3, ¶ 7, examiner notes Evanghelidis polymeric fibers are obtained by electrospinning). Claims 6 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Wu (MDPI, "High-sensitive ammonia sensors based on tin monoxide nanoshells,2019; "Wu") and Evanghelidis (RO 129633; "Evanghelidis"), as applied to claim 1, in view of Wang ("Zinc oxide core–shell hollow microspheres", 2011; "Wang"). Regarding claim 6, Wu and Evanghelidis fail to disclose the oxide is zinc oxide. Wang teaches the metal oxide is zinc oxide (ABSTRACT, Wang’s chemical gas sensor is fabricated from spherically multilayered core-shell ZnO structure. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use Wang’s scheme of fabricating a gas sensor using a multi-shelled ZnO core shell structure in place of Wu and Evanghelidis’ SnO to detect species such as toluene. Doing so increases the application of the sensors. Regarding claim 9, Wu, Evanghelidis and Wang disclose, the polymer fiber substrate (Wu, p. 3, ¶ 4, Wu’s sensors are welded on substrates, also see Evanghelidis’ translation, p. 3, ¶ 7, “polymeric fiber networks”) is prepared by electrospinning (see Evanghelidis’ translation, p. 3, ¶ 7, examiner notes Evanghelidis polymeric fibers are obtained by electrospinning). Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Wu (MDPI, "High-sensitive ammonia sensors based on tin monoxide nanoshells,2019; "Wu") and Evanghelidis (RO 129633; "Evanghelidis") and Wang ("Zinc oxide core–shell hollow microspheres", 2011; "Wang"), as applied to claim 6, in view of Jamil ("Zinc oxide hollow micro spheres", 2014; "Jamil"). Regarding claim 7, Wu, Evanghelidis and Wang disclose the gas sensor (Wang, p. 1, ¶ 4, “Wang’s ZnO is sensitive to ethanol, carbon monoxide, acetone, etc”). Examiner notes that the limitation: “for detecting NH3” is an intended use type statement. Applicant is reminded that a claim containing a “recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus” if the prior art apparatus teaches all the structural limitations of the claim. See MPEP 2114. Wu, Evanghelidis and Wang fail to explicitly disclose the gas sensor is for detecting NH3. Jamil teaches the gas sensor is for detecting NH3 (p. 5, ¶ 1, examiner notes ZnO sensors are fabricated to sense ammonia). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use Jamil’s teaching of ZnO gas sensors used for sensing ammonia teach Wu, Evanghelidis and Wang to detect ammonia. Doing so increases the application of the sensors. Allowable Subject Matter Claim 10 is allowed. The following is an examiner’s statement of reasons for allowance: Regarding claim 10, although combine Wu and Evanghelidis teach a method of synthesizing high-sensitive ammonia sensors with metal oxide nanoshells welded on polymeric fiber networks; combined Wu and Evanghelidis do not teach applicant’s method of making a gas sensor including heating to remove polymeric fibers on which the metal oxide nanoshell has been deposited. Furthermore, no other prior art can be found to motivate or teach applicant’s method including depositing a metal oxide on the polymeric fibers wherein a metal oxide nanoshell is produced on the polymeric fibers; and heating the polymer fibers and metal oxide in air to remove the polymeric fibers, in combination with the remaining limitations of the claim. Claims 4 and 8 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to TIMOTHY P GRAVES whose telephone number is (469)295-9072. The examiner can normally be reached M-F 8 a.m. - 5 p.m.. 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, Peter Macchiarolo can be reached at 571-272-2375. 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. /TIMOTHY P GRAVES/Primary Examiner, Art Unit 2855
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Prosecution Timeline

Jan 17, 2024
Application Filed
Mar 02, 2026
Non-Final Rejection — §103 (current)

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Prosecution Projections

1-2
Expected OA Rounds
81%
Grant Probability
97%
With Interview (+15.9%)
2y 8m
Median Time to Grant
Low
PTA Risk
Based on 449 resolved cases by this examiner. Grant probability derived from career allow rate.

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