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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 8/16/2024 has been considered by the examiner.
Election/Restrictions
Applicant's election of Group I and Species A, Claim 1, in the reply filed on 04/24/2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
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 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 1 is rejected under 35 U.S.C. 103 as being unpatentable over Kodu et al. (Margus Kodu et al., Structure-dependent CO2 gas sensitivity of La2O2CO3 thin films, Hindawi Journal of Sensors 2017, pgs 1-6, cited in IDS), and in view of Langenbacher et al. (US 2009/0145220 A1). Kodu and Langenbacher are provided in IDS filed on 8/16/2024.
Regarding claim 1, Kodu teaches a gas sensor (gas sensitive La2O2CO3 thin film sensor [title; abstract]); The preamble limitation wherein the gas sensor is a “carbon dioxide” gas sensor is a statement of intended use that does not further limit the claimed invention [see MPEP 2111.02]. While features of an apparatus may be recited either structurally or functionally, claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function. In re Schreiber, 128 F.3d 1473, 1477-78, 44 USPQ2d 1429, 1431-32 (Fed. Cir. 1997) [MPEP 2114]. Since the structure of the prior art teaches all of the structural limitations of the claim, the structure is considered capable of meeting the intended use limitations. Furthermore, Kodu does teach the gas sensor is a CO2 gas sensor (title and abstract). The gas sensor comprising:
an insulating substrate and a gas sensing layer formed on one major surface of the insulating substrate via electrodes (a microelectrode substrate that comprises a passivated Si/SiON substrate wherein a La2O2CO3 gas sensitive film was deposited on the electrodes and connected with an instrument using electrical contacts [Pgs. 1-2; 2. Materials and Methods; Fig. 1]), wherein the gas sensing layer comprises Ln2O2CO3 has a hexagonal crystal structure (rare earth metal oxycarbonate is La2O2CO3 and consists of type (II) hexagonal La oxycarbonate crystal phase [All of Pg. 3]).
Kodu is silent on the exact purity of the hexagonal phase of the La2O2CO3 and thus fails to expressly teach “wherein at least 95% of the La2O2CO3 has a hexagonal crystal structure” as required by claim 1.
Kodu does teach wherein the La2O2CO3 material is formed by PLD using a target consisting mainly of hexagonal La2O2CO3 with only small traces of monoclinic phase [Pg. 3, left col., first paragraph]. Kodu further teaches that the final product using an ex-situ annealing process forms films that consist of type (II) hexagonal La oxycarbonate crystal phase and that Raman spectrum of the film annealed ex situ demonstrated peaks that are clearly traced to hexagonal La2O2CO3. Kodu further teaches that amorphous La2O2CO3 can be converted to hexagonal through ex situ annealing at 550°C [all of Pg. 3; Figs. 3-4].
Although Kodu does not expressly state wherein 95% of La2O2CO3 has a hexagonal crystal structure, it is the examiner’s position that the disclosed teachings of Kodu yield a material that is close enough to pure, having only trace amounts of monoclinic crystal phase, that one of ordinary skill in the art at the time of the invention would have expected the same properties. Case law holds that a prima facie case of obviousness exists where the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have the same properties [MPEP § 2144.05(I)]. Furthermore, differences in concentration will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration is critical. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." MPEP § 2144.05(II)(A). Therefore, it would have been obvious to one skilled in the art to use La2O2CO3 with a crystal phase that is at least 95% hexagonal as such structure will function in a predictable manner given these conditions and is clearly the desired structure present in Kodu, which teaches the exact method for converting amorphous La2O2CO3 into the desired hexagonal structure using ex situ annealing.
Kodu further teaches wherein the La2O2CO3 films are formed by PLD and form particles that are grown on the substrate [see Fig. 5]. It is the Office’s position that the formation of particles on a surface would inherently form at least some pores as clearly shown in Fig. 5. However, Kodu does not expressly state that pores are present or disclose the size of such pores and thus fails to expressly state that the gas sensing layer of La2O2CO3 “having micropores” as required by instant claim 1.
One skilled in the art would readily appreciate, however, that the formation of micropores in a gas sensor is well-known to improve sensor response by allowing gas to permeate into the gas sensing layer. For example, Langenbacher discloses a gas sensor comprising an electrode substrate with a gas-sensitive layer disposed on the electrode substrate [Para. 0049; Fig. 1]. Langenbacher further teaches that it is desirable for the gas-sensitive layer to have an optimized pore size distribution with a micron-range average [Para. 0015]. Langenbacher teaches that the diffusion process of the test gas into the gas-sensitive layer naturally takes a certain amount of time, which determines the response time of the gas sensor. In order to accelerate the gas sensor response, it is desirable to make the electrode structure permeable for the gas to be detected to allow for diffusion of the gas molecules over a large area and thus the pore size optimization allows for an improved response time of the sensor [Paras. 0015-0016].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the gas sensing layer of Kodu to comprise pores/micropores in light of the teachings of Langenbacher. Specifically, Langenbacher teaches that the diffusion of gas through the gas-sensitive layer and subsequently the electrode system depends upon the pore size distribution/porosity of the structure. Since this particular parameter is recognized as result-effective variable, i.e., a variable which achieves a recognized result, the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See In re Boesch, 617 F. 2d 272, 205 U.S.P.Q. 215 (C.C.P.A. 1980). Thus, it would be obvious to one skilled in the art at the time of the claimed invention to modify/optimize the pore size of the gas-sensitive layer disclosed by Kodu to yield an expected result of an optimized/improved response time to the test gas.
The limitation “resulting from a solid powder of an oxalate of La” is a product-by-process limitation. There is no apparent difference between the apparatus as claimed and the prior art as taught by modified Kodu above.
Although Kodu does not explicitly teach wherein the electrodes have a gap therebetween of 10 µm.
Kodu does teach the electrode separation distance ranges from 4 to 200 µm (the first paragraph in Col. 1 on page 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use an electrode separation distance within the disclosed range, as taught by Kodu, including those amounts that overlap within the claimed range, since one of ordinary skill in the art would reasonably expect any value within the taught range to be suitable given that Kodu specifically teaches the range to be suitable for the electrode separation distance for sensing CO2 gas. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I).
The limitation “a sensitivity (α) of the gas sensing layer is greater than or equal to 0.4, wherein the sensitivity (α) is defined as Rg/R0 = A×[CO2 concentration]α, A is a constant number, and Rg/R0 is a ratio of a direct current electrical resistance of the gas sensing layer after an aging test at 350 °C divided by the direct current electrical resistance of the gas sensing layer before the aging test, when the direct current electrical resistance of the gas sensing layer is measured between the electrodes having a gap therebetween of 10 µm” is a functional recitation. Apparatus claims cover what a device is, not what a device does [MPEP 2114(II)]. A functional recitation of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. See MPEP 2114. In the instant case, modified Kotu teaches the gas sensor
comprising substantially the same elements or components as that of the applicant, as outlined in the rejection above, it is contended that the gas sensor of the prior art is capable of delivering the same sensitivity level. Accordingly, products of identical chemical composition cannot have mutually exclusive properties, and thus, the claimed property (i.e. the sensitivity of the gas sensing layer), is necessarily present in the prior art gas sensing layer material. The courts have held that “[p]roducts of identical chemical composition cannot have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP 2112.01 (II).
Conclusion
The prior arts made of record and not relied upon are considered pertinent to applicant's disclosure: Chuang et al. (A printable conductive polymer CO2 sensor with high selectivity to humidity, Transducers 2017, 1501-1503) teaches a CO2 gas sensor as shown in Fig.1. Rheal et al. (On the rare earth dioxymonocarbonates and their decomposition, Inorganic chemistry, 1969, 8, 238-246) teaches type II La2O2CO3. Gore et al. (US20110280956A1) teaches a method of producing a lanthanum carbonate hydroxide or lanthanum oxycarbonate. Moerck et al. (US20060003018A1) teaches rare earth metal compounds, particularly lanthanum.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHIZHI QIAN whose telephone number is (571)272-3487. The examiner can normally be reached Monday-Thursday 8:00 am-5:00 pm.
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 V. Van can be reached on (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.
/SHIZHI QIAN/Examiner, Art Unit 1795
Prosecution Insights