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 .
Claim Objections
Claims 28-31 are objected to because of the following informalities: in claim 28, “the second polymer exchange membrane” (last line) appears to be a mistake and should likely be --the second proton exchange membrane--. Claims 29-31 are objected to because of their dependence on claim 28. Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1-4, 12-15, 19, 21, 24 and 25 is/are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Pratt et al. (US 2019/0041351).
Regarding claims 1-4, Pratt et al. disclose a hydrogen gas sensor, the hydrogen gas sensor comprising:
(a) a housing 101, the housing including a cavity 120 and an aperture 107, the aperture permitting gas from outside the housing to enter the cavity (par. 0028);
(b) a first proton exchange membrane 103, the first proton exchange membrane being disposed within the cavity (see Fig. 1, see pars. 0040 and 0043);
(c) a working electrode 104, the working electrode being disposed within the cavity and coupled to the first proton exchange membrane 103;
(d) a reference electrode 105, the reference electrode being disposed within the cavity and coupled to the first proton exchange membrane; and
(e) a first counter electrode 106, the first counter electrode being disposed within the cavity and coupled to the first proton exchange membrane (see Fig. 1 and par. 0027), wherein the first counter electrode 106 comprises ruthenium oxide, which is a transition metal oxide and is a material with pseudo-capacitor characteristics capable of proton intercalation (par. 0036).
Regarding claims 12 and 13, Pratt et al. disclose that the reference electrode 105 comprises one or more pseudo-reference electrode materials which is at least one member selected from the group consisting of silver, a silver halide, gold, platinum, and platinum black (par. 0036, reference electrode is Ag/AgCl, platinum, and/or gold).
Regarding claim 14, Pratt et al. disclose the hydrogen gas sensor further comprising a substrate 102, the substrate comprising opposing top and bottom surfaces, wherein each of the working electrode 104, the reference electrode 105, and the first counter electrode 106 is disposed over the top surface of the substrate 102 (see Fig. 1), and wherein at least a portion of the first proton exchange membrane 103 is disposed over and in direct contact with each of the working electrode, the reference electrode, and the first counter electrode (Id.).
Regarding claim 15, Pratt et al. disclose that the substrate 102 is made of one or more electrically non-conductive, chemically inert materials (par. 0033, substrate is made of silicon or silicon oxide or silicon nitride).
Regarding claim 19, Pratt et al. disclose the gas sensor further comprising a permselective coating 202, the permselective coating being disposed on the first proton exchange membrane to inhibit interfering gas species from reaching one or more of the working electrode, the reference electrode, and the first counter electrode (par. 0055).
Regarding claim 21, Pratt et al. disclose Pratt et al. disclose that the first proton exchange membrane 103 comprises a perfluorosulfonic acid polymer (par. 0043, membrane 103 is Nafion which is a perfluorosulfonic acid polymer).
Regarding claims 24 and 25, Pratt et al. the hydrogen gas sensor further comprising a protective barrier, the protective barrier being positioned in the cavity to block particulate matter and water from reaching at least one of the working electrode, the reference electrode, and the first counter electrode, and wherein the protective barrier comprises porous polytetrafluoroethylene (PTFE) (see par. 0049, PTFE used in or around aperture 107).
Claim Rejections - 35 USC § 103
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.
Claim(s) 20, 32 and 35-37 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pratt et al. (US 2019/0041351).
Regarding claim 20, Pratt et al. do disclose that the permselective coating 202 comprises at least one material selected from the group consisting of polymethylmethacrylate, fluorinated ethylene propylene, polyaniline, polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF) (par. 0057).
Pratt et al. do not disclose the permselective coating having a thickness of about 100 to 1000 microns. It would have been obvious to one of ordinary skill in the art before the effective filing date to have adjusted the thickness of the permselective coating to be any of various values, including between 100 and 1000 microns, because increasing the thickness to these values would have predictably provided a more robust protective coating.
Regarding claims 32 and 35-37, Pratt et al. disclose a method for assessing hydrogen gas purity, the method comprising the steps of:
(a) providing a hydrogen gas sensor 100, the hydrogen gas sensor comprising:
(i) a proton exchange membrane 103,
(ii) a working electrode 104, the working electrode coupled to the proton exchange membrane,
(iii) a reference electrode 105, the reference electrode coupled to the proton exchange membrane (see Fig. 1), and
(iv) a first counter electrode 106, the first counter electrode comprising ruthenium oxide, which is a transition metal oxide and a material with pseudo-capacitor characteristics capable of proton intercalation (par. 0036);
(b) applying a first potential difference between the working electrode and the reference electrode (par. 0053);
(c) exposing a hydrogen gas sample to the working electrode, whereby hydrogen gas is oxidized at the working electrode and protons travel from the working electrode to the first counter electrode via the proton exchange membrane and are stored in the first counter electrode (par. 0050, hydrogen gas sensed; par. 0052, target gas in contact with working electrode 104 through capillary 113); and
(d) measuring an oxidation current as the hydrogen gas sample is oxidized (par. 0053).
Pratt et al. do not explicitly disclose the step (e) comparing the measured oxidation current to standards to assess hydrogen gas purity. The step of comparing measured values to known standards, references and thresholds has been known in the art as a means to determine whether measured parameters such as gas concentration are within acceptable or desired limits. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date to have included in the method of Pratt et al. a step of comparing the measured oxidation current to standards to assess hydrogen gas purity, in order to determine whether the hydrogen gas levels are within acceptable limits and to determine whether corrective measures need to be employed.
Claim(s) 5, 6, 38 and 39 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pratt et al. (US 2019/0041351) in view of Silvester et al. (US 2015/0247818).
Regarding claims 5, 6, 38 and 39, Pratt et al. do not disclose the first counter electrode surface area being greater than the working electrode surface area. Silvester et al. disclose an electrochemical hydrogen gas sensor, with a working electrode 14, counter electrode 16 and reference electrode 18, wherein the counter electrode surface area is at least twice the working electrode surface area (par. 0058). It would have been obvious to one of ordinary skill in the art before the effective filing date to have designed the counter electrode surface area to be at least twice the working electrode surface area, as taught by Silvester et al., in the sensor and method of Pratt et al. because it would ensure that the counter electrode reaction can proceed as fast as the oxidation reaction and not limit the total current or cause inaccurate readings.
Claim(s) 22 and 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Pratt et al. (US 2019/0041351) in view of Moon et al. (US 2008/0128285).
Regarding claim 22, Pratt et al. do not disclose the specific thickness of the first proton exchange membrane. Moon et al. disclose a hydrogen gas sensor with a proton exchange membrane 106, a working electrode 103, a reference electrode 105, and a counter electrode 104, with the proton exchange membrane disposed over the electrodes (see Fig. 3), and Moon et al. further teach that the proton exchange membrane 106 can have any of various thicknesses based on the particular size of the sensor and may be in a range of several tens to thousands of micrometers (par. 0041), which includes thicknesses in the claimed range of 50 to 500 microns. It would have been obvious to one of ordinary skill in the art before the effective filing date to have made the thickness of the proton exchange membrane in Pratt to be any of various thicknesses in the range of 50 to 500 microns, as taught by Moon et al., because adjusting the thickness of the membrane to different thickness values would allow the membraned to adequately cover and function with different sizes and thicknesses of electrodes and sensor substrates.
Regarding claim 26, Pratt et al. disclose that the first proton exchange membrane 103 has opposing first and second surfaces, wherein the working electrode 104 has opposing first and second surfaces, and wherein the first surface of the working electrode is positioned in direct contact with the first surface of the first proton exchange membrane (see Fig. 1).
Pratt et al. do not disclose that the first surface of the first counter electrode 106 is positioned in direct contact with the second surface of the first proton exchange membrane. Moon et al. teach in their gas sensor, the first surface of the working electrode 103 being positioned in direct contact with a first surface of the first proton exchange membrane 106, and wherein a first surface of the first counter electrode 104 is positioned in direct contact with the second surface of the first proton exchange membrane 106 (see Fig. 4 showing working electrode 103 on opposite surface of membrane 106 from counter electrode 104). It would have been obvious to one of ordinary skill in the art before the effective filing date to have positioned the working electrode and the counter electrode on opposing surfaces of the proton exchange membrane, as taught by Moon et al., in the sensor of Pratt et al., because it would have allowed the sensor to be more compact in size.
Allowable Subject Matter
Claims 40-54 are allowed.
Claims 7-11, 16-18, 23, 27-31, 33 and 34 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 and to correct any other objections set forth above.
The following is a statement of reasons for the indication of allowable subject matter:
With regard to claims 7 and 16, Pratt et al. fail to teach or suggest a second counter electrode that is coupled to or in contact with the first proton exchange membrane.
With regard to claim 23, Pratt et al. fail to teach or suggest the sensor comprising a sorbent material containing water for use in keeping the first proton exchange membrane hydrated, the sorbent material being disposed within the cavity and coupled to the first proton exchange membrane.
With regard to claim 27, neither Pratt et al. nor Moon et al. teach or suggest the first surface of the reference electrode being positioned in direct contact with the first surface of the first proton exchange membrane along with the working electrode; Moon et al. only teach the working electrode being in contact with first surface of the membrane, with the counter electrode and reference electrode being in contact with the second surface of the membrane.
With regard to claim 28, Pratt et al. fails to teach or suggest the sensor further comprising a second proton exchange membrane, wherein the second proton exchange membrane is disposed within the cavity, wherein the second proton exchange membrane has opposing first and second surfaces, and wherein the second surface of the first counter electrode is in direct contact with the first surface of the second proton exchange membrane.
With regard to claim 33, Pratt et al. fail to teach or suggest the method of claim 32 further comprising, after step (d), applying a second potential difference between the working electrode and the reference electrode to strip any contaminants from the working electrode.
With regard to claims 40 and 48, Pratt et al. teach many of the limitations, which are similar to limitations in claim 32; Pratt et al. fail to teach or suggest the provided hydrogen gas sensor comprising a second counter electrode coupled to the proton exchange membrane.
Conclusion
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/PAUL M. WEST/ Primary Examiner, Art Unit 2855