DETAILED ACTION
This action is in response to the amendments and remarks filed 12/17/2025, in which claims 1-2, 10, 12, 14, 17, 20-22, 25 and 27-30 have been amended and claims 1-4, 7-12, 14-17 and 20-30 are pending and ready for examination.
Information Disclosure Statement
The information disclosure statement(s) (IDS) submitted on 17 DECEMBER 2025 is/are in compliance with the provisions of 37 CFR 1.97 and has/have been considered. An initialed copy of Form 1449 is enclosed herewith.
Claim Interpretation
The term “pure draw solution” is interpreted to mean a solution not containing the one or more ions.
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.
Claims 1-4, 7-12, 20, 22 and 29 are rejected under 35 U.S.C. 103 as being unpatentable over US 2014/0076728 A1 (hereinafter “Prakash”) in view of US 2017 /0030890 Al (hereinafter “Holweg”).
Regarding Claim 1 Prakash discloses a membrane system (including nanofiltration [0046]) for electrically conductive membrane separation [0008], [0034] comprising:
a conductive membrane filter 110/210, the membrane may be used for nanofiltration [0046] and thus may obviously have a nanoporous structure;
an electrical contact 240 in contact with the conductive membrane filter 210; and
a counter electrode 240/260 above a top surface of the conductive membrane filter/electrode [0034]-[0036];
wherein the conductive membrane filter, via the electrical contact, and the counter electrode are configured to:
generate an electric field between the conductive membrane filter and the counter electrode, hold the conductive membrane filter at a constant electric potential, or flow constant current into the conductive membrane filter [0008], [0027]-[0028], [0034], and
wherein the conductive membrane filter is configured to separate one or more ions from a mixture solution into a permeate solution [0034], [0043], [0050], Examples; Figs. 1A-4.
wherein the membrane may be a nanofiltration membrane, ultrafiltration membrane, microfiltration membrane, or reverse osmosis membrane, ([0015], Claim 16), i.e. which have pore ranges which overlap those claimed, [0047]-[0048].
Prakash does not disclose the membrane filter comprises monolithic silicon having a nanoporous structure with pores sizes ranging from 1 nm to 500nm.
However, with regard to the membrane Prakash discloses the membrane used may be “reverse osmosis (RO) membranes, nanofiltration (NF) membranes, ultrafiltration (UF) membranes, and microfiltration (MF) membranes”, and may be “formed from metals” [0049]. Further, Holweg discloses a similar membrane filtration system for electrically conductive membrane separation [0138]-[0141] comprising: a conductive membrane filter 150, [0136] and which may be formed from etching a silicon wafer, and may thus comprise monolithic silicon, [0053]-[0055] [0066], [0109]-[0117], Figs. 10A-11, 27-29.
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the system of Prakash by substituting for the conductive membrane filter an etched-pore monolithic silicon conductive membrane as discleod by Holweg because this involves the simple substitution of known conductive membranes used in fluid separation to obtain the predictable result of forming a successful conductive membrane separation system.
Thus in the combined invention, one would use the method and materials of Holweg (monolithic wafer silicon that is etched) to form a membrane suitable for the apparatus and processes of Prakash, i.e. having the pore size(s) of the membrane disclosed by Prakash, using etching means known in the art, so the system can achieve the filtration separations as disclosed. Thus it is obvious for the membrane of the combined invention to have pore sizes for microfiltration (pores greater than 0.1 micron), ultrafiltration (pores between 2-100 nm), nanofiltration (pores between 1-2 nm) or reverse osmosis filtration (pores less than 1 nm), Prakash [0034], [0046]-[0048]; i.e. which have pore size ranges which overlap those claimed. While Holweg discloses a membrane for microfiltration, and would thus be obvious to have “pores greater than 0.1 micron” as disclosed by Prakash, the pore size of Holweg not seen to be limiting to the combined invention, since it is not Holweg’s overall apparatus or process that is being modified and there is no teaching away from the pore sizes being in the ranges used by Prakash.
Since the range(s) disclosed overlaps the range(s) claimed, the range(s) recited in the claim is/are considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range(s) that corresponds to the claimed range. See MPEP 2144.05(I).
Regarding Claims 2-4 Prakash in view of Holweg discloses the system of claim 1, wherein the mixture is the material worked upon by the apparatus, and thus does not further limit the apparatus, and therefore further limitations to the mixture are not seen to further limit the apparatus of claim 1. Further, since the prior art in combination discloses a conductive, etched silicone filter with pores in the range claimed, i.e. of the same composition as claimed and disclosed by Applicants, it is asserted, absent evidence to the contrary, that one would reasonably expect that the membrane disclosed by Prakash in view of Holweg inherently has the same properties as recited. Specifically, it is asserted that the membrane filter is configured to separate one or more ions from a mixture solution, including where the one or more ions is selected from the group consisting of Co, Ni, Mn, Fe, Li, Cu, Ag, Zn ions or mixtures therefore, and the mixture solution comprises an acid and the mixture solution has a pH less than 4.0, and wherein the acid comprises H2SO4. See MPEP 2112.01.
Regarding Claim 7 Prakash in view of Holweg discloses the system of claim 1, wherein the system is seen to be configured for electro-filtration and the electric field is applied between the membrane filter and the counter electrode; see [0026]-[0034], Examples; though it is noted that this is an apparatus claim and this is a functional limitation; claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function (see MPEP 2114).
Regarding Claims 8 and 10 Prakash in view of Holweg discloses the system of claims 7 and 9, wherein, as discussed supra, the membrane of Prakash may be a nanofiltration membrane, ultrafiltration membrane, microfiltration membrane, or reverse osmosis membrane, (Prakash [0015], Claim 16), i.e. which have pore ranges which overlap those claimed Prakash [0047]-[0048].
Thus pore size thus a variable which achieves a recognized result (determines size of particles retained by the filter), and it would therefore have been obvious for one of skill in the art to optimize this variable through routine experimentation, by using values including those within the scope of the present claims, so as to produce desired end results. See MPEP § 2144.05 (B).
Since the range(s) disclosed overlaps the range(s) claimed, the range(s) recited in the claim is/are considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range(s) that corresponds to the claimed range. See MPEP 2144.05(I).
Regarding Claim 9 Prakash in view of Holweg discloses the system of claim 1, wherein the system is seen to be configured for electro-extraction and the membrane filter is capable to being held at a constant electrical potential or having a constant current driven through the membrane filter; see Prakash [0026]-[0034], Examples; though it is noted that this is an apparatus claim and this is a functional limitation; claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function (see MPEP 2114).
Regarding Claim 11 Prakash in view of Holweg discloses the system of claim 1, wherein the electric field strength and polarity are seen to be adjustable to select for the desired component; Prakash [0026]-[0034], Examples; though it is noted that this is an apparatus claim and this is a functional limitation; claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function (see MPEP 2114).
Regarding Claim 12 Prakash discloses a method for electrically conductive membrane separation of one or more ions from a mixture solution comprising:
providing a membrane nanofiltration system [0046] comprising:
a conductive membrane filter 110/210, the membrane may be used for nanofiltration [0046] and thus may have a nanoporous structure;
an electrical contact 240 in contact with the conductive membrane filter 110/210; and
a counter electrode 240/260 above a top surface of the conductive membrane filter [0034]-[0036].
generating an electric field above or within a conductive membrane filter 110/210, [0008], [0026]-[0034], Examples, and;
feeding the mixture solution through the conductive membrane filter; and
separating the one or more ions from the mixture solution into a permeate solution [0034], [0043], [0050], Examples; Figs. 1A-4,
wherein the membrane may be a nanofiltration membrane, ultrafiltration membrane, microfiltration membrane, or reverse osmosis membrane, (Prakash [0015], Claim 16), i.e. which have pore ranges which overlap those claimed Prakash [0047]-[0048].
Prakash does not disclose the membrane filter comprises monolithic silicon having a nanoporous structure with pores sizes ranging from 1 nm to 500nm.
However, with regard to the membrane Prakash discloses the membrane used may be “reverse osmosis (RO) membranes, nanofiltration (NF) membranes, ultrafiltration (UF) membranes, and microfiltration (MF) membranes”, and may be “formed from metals” [0049]. Further, Holweg discloses a similar membrane filtration system for electrically conductive membrane separation [0138]-[0141] comprising: a conductive membrane filter 150, [0136] and which may be formed from etching a silicon wafer, and may thus comprise monolithic silicon, [0053]-[0055] [0066], [0109]-[0117], Figs. 10A-11, 27-29.
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Prakash by substituting for the conductive membrane filter an etched-pore monolithic silicon conductive membrane as discleod by Holweg because this involves the simple substitution of known conductive membranes used in fluid separation to obtain the predictable result of forming a successful conductive membrane separation system.
Thus in the combined invention, one would use the method and materials of Holweg (monolithic wafer silicon that is etched) to form a membrane suitable for the appatus and processes of Prakash, i.e. having the pore size(s) of the membrane disclosed by Prakash, using etching means known in the art, so the system can achieve the filtration separations as disclosed. Thus it is obvious for the membrane of the combined invention to have pore sizes for microfiltration (pores greater than 0.1 micron), ultrafiltration (pores between 2-100 nm), nanofiltration (pores between 1-2 nm) or reverse osmosis filtration (pores less than 1 nm), Prakash [0034], [0046]-[0048]; i.e. which have pore size ranges which overlap those claimed. While Holweg discloses a membrane for microfiltration, and would thus be obvious to have “pores greater than 0.1 micron” as disclosed by Prakash, the pore size of Holweg not seen to be limiting to the combined invention, since it is not Holweg’s overall apparatus or process that is being modified and there is no teaching away from the pore sizes being in the ranges used by Prakash.
Since the range(s) disclosed overlaps the range(s) claimed, the range(s) recited in the claim is/are considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range(s) that corresponds to the claimed range. See MPEP 2144.05(I).
Regarding Claim 20 Prakash in view of Holweg discloses the method of claim 12, wherein the one or more ions are separated from the mixture solution via electro-filtration and the electric field is applied between the conductive membrane filter and the counter electrode ([0026]-[0034], Examples).
Regarding Claim 22 Prakash in view of Holweg discloses the method of claim 12, wherein one or more ions of the mixture not in a permeate solution is retained within the pores of the conductive membrane filter, i.e. inherently via sieving properties of the membrane this will necessarily occur when in use; see MPE 2112.
Regarding Claim 29 Prakash discloses a method for electrically conductive membrane separation of one or more ions from a mixture solution comprising:
holding a conductive membrane filter 110/210 at a constant electric potential or driving a constant current through the membrane filter;
feeding a mixture solution through the conductive membrane filter; and
separating the one or more ions from the mixture solution; ([0026]-[0034], [0043], [0050], Examples; Figs. 1A-4),
wherein the conductive membrane filter may be used for nanofiltration [0046] and thus may have a nanoporous structure.
wherein the membrane may be a nanofiltration membrane, ultrafiltration membrane, microfiltration membrane, or reverse osmosis membrane, (Prakash [0015], Claim 16), i.e. which have pore ranges which overlap those claimed Prakash [0047]-[0048].
Prakash does not disclose the membrane filter comprises monolithic silicon having a nanoporous structure with pores sizes ranging from 1 nm to 500nm.
However, with regard to the membrane Prakash discloses the membrane used may be “reverse osmosis (RO) membranes, nanofiltration (NF) membranes, ultrafiltration (UF) membranes, and microfiltration (MF) membranes”, and may be “formed from metals” [0049]. Further, Holweg discloses a similar membrane filtration system for electrically conductive membrane separation [0138]-[0141] comprising: a conductive membrane filter 150, [0136] and which may be formed from etching a silicon wafer, and may thus comprise monolithic silicon, [0053]-[0055] [0066], [0109]-[0117], Figs. 10A-11, 27-29.
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Prakash by substituting for the conductive membrane filter an etched-pore monolithic silicon conductive membrane as discleod by Holweg because this involves the simple substitution of known conductive membranes used in fluid separation to obtain the predictable result of forming a successful conductive membrane separation system.
Thus in the combined invention, one would use the method and materials of Holweg (monolithic wafer silicon that is etched) to form a membrane suitable for the appatus and processes of Prakash, i.e. having the pore size(s) of the membrane disclosed by Prakash, using etching means known in the art, so the system can achieve the filtration separations as disclosed. Thus it is obvious for the membrane of the combined invention to have pore sizes for microfiltration (pores greater than 0.1 micron), ultrafiltration (pores between 2-100 nm), nanofiltration (pores between 1-2 nm) or reverse osmosis filtration (pores less than 1 nm), Prakash [0034], [0046]-[0048]; i.e. which have pore size ranges which overlap those claimed. While Holweg discloses a membrane for microfiltration, and would thus be obvious to have “pores greater than 0.1 micron” as disclosed by Prakash, the pore size of Holweg not seen to be limiting to the combined invention, since it is not Holweg’s overall apparatus or process that is being modified and there is no teaching away from the pore sizes being in the ranges used by Prakash.
Since the range(s) disclosed overlaps the range(s) claimed, the range(s) recited in the claim is/are considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range(s) that corresponds to the claimed range. See MPEP 2144.05(I).
Claims 14-16 are rejected under 35 U.S.C. 103 as being unpatentable over Prakash in view of Holweg further in view of in view of C. Lupi, et al, Nickel and cobalt recycling from lithium-ion batteries by electrochemical processes, Waste Management, Volume 25, Issue 2, 2005, Pages 215-220 (hereinafter “Lupi”, provided with the IDS dated 10/04/2024).
Regarding Claim 14-16 Prakash in view of Holweg discloses the method of claim 12, but does not disclose wherein the component of the mixture solution is selected from the group consisting of ions of Co, Ni, Al, Mn, Fe, Li, Cu, Ag, Zn, ions thereof, or mixtures thereof, or (claim 15) wherein the mixture solution comprises an acid and the mixture solution has a pH less than 4.0 or (claim 16) wherein the acid is H2SO4.
However Lupi discloses it is known to use a membrane electro filtration/separation process to separate Ni and Co from an H2SO4 acid solution to recovery metals from battery recycling, at pH’s from 3-4.2 (Abstract, Secs. 2. 2.1. 2.2. Fig. 1).
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the process of Prakash in view of Holweg by using the method and apparatus to separate Ni and Co from an H2SO4 acid solution of pH 3-4.2 as disclosed by Lupi because this involves the simple substitution of known solutions which may be separated by electrochemical membrane means to obtain the predictable result of successful separation.
Claims 17, 21 and 28 are rejected under 35 U.S.C. 103 as being unpatentable over Prakash in view of Holweg further in view of US 2012/0234694 A1 (hereinafter “Vecitis”).
Regarding Claim 17 Prakash in view of Holweg discloses the method of claim 12, but does not appear to disclose wherein the electric field is configured to separate components with lower charges into a permeate solution and components with higher charges into a retentate solution.
However Vecitis discloses a similar membrane electrofiltration apparatus and method of its use (Fig. 1A, [0010], [0033], [0125]-[0127], [0182]-[0183], [0188]-[0190]), wherein the electric field may be run in either polarity direction [0708] and is controlled to adsorb or desorb charged molecules ([0209], [0381]) of either positive or negative charge [0220], similar to that of Prakash and it thus before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the method of Prakash in view of Holweg by separating components with lower charges into the permeate solution and components with higher charges into a retentate solution, or vice versa, as desired.
Regarding Claim 21 Prakash in view of Holweg discloses the method of claim 12, but does not appear to disclose wherein the component is separated from the mixture solution via electro-extraction and the conductive membrane filter is held at a constant electric potential or has a constant current driven through the membrane filter.
However Vecitis discloses a similar membrane electrofiltration apparatus and method of its use (Fig. 1A, [0010], [0033], [0125]-[0127], [0182]-[0183], [0188]-[0190]), wherein the component is separated from the mixture solution via electro-extraction (i.e. adsorption into the membrane [0189]-[0190], [0209]) and the membrane filter is held at a constant electric potential (see Examples 4-5, where adsorption occurs during electro-filtration and thus “electro-extraction” is also occurring).
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the method of Prakash in view of Holweg by separating the component from the mixture solution via electro-extraction where the conductive membrane filter is held at a constant electric potential or has a constant current driven through the membrane filter as in Vecitis in order to remove the component via the alternative process of electro-extraction and adsorption into the membrane.
Regarding Claim 28 Prakash in view of Holweg discloses the method of claim 12, but does not appear to disclose further comprising adjusting the electric field strength or polarity to select for the desired component.
However Vecitis discloses a similar membrane electrofiltration apparatus and method of its use (Fig. 1A, [0010], [0033], [0125]-[0127], [0182]-[0183], [0188]-[0190]), further comprising adjusting the electric field strength or polarity to select for the desired component [0193].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the method of Prakash in view of Holweg by adjusting the electric field strength or polarity to select for the desired component as in Vecitis in order to control selectivity of the membrane process as desired for different components.
Claims 23-27 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Prakash in view of Holweg further in view of US 2012/0234694 A1 (hereinafter “Vecitis”) and US 2003/0106798 A1 (hereinafter “Seabrook”).
Regarding Claim 23, 25 and 30 Prakash in view of Holweg discloses the method of claim 22 and 29, but does not disclose: (claim 23) further comprising reversing the polarity of the electric potential or direction of the current and passing a pure draw solution through the membrane filter; or (claim 25) further comprising leaching the one or more components retained in the membrane filter into a pure product stream comprising the pure draw solution and the one or more components; or (claim 30) further comprising reversing the polarity of the electric potential or direction of the current and passing a pure draw solution through the membrane filter to leach one or more components retained in the membrane filter.
However Vecitis discloses a similar membrane electrofiltration apparatus and method of its use (Fig. 1A, [0010], [0033], [0125]-[0127], [0182]-[0183], [0188]-[0190]), wherein materials “adsorbed on the carbon nanotube filter material can be desorbed and collected as a more concentrated solution ( e.g., for further analysis) at an appropriate potential, while simultaneously regenerating the carbon nanotube filter” wherein a “contaminant-free fluid” is used for the collection/concentration/regeneration [0209],
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the method of Prakash in view of Holweg by additionally desorbing the materials adsorbed onto the membrane by passing a contaminant-free fluid through the filter at an appropriate potential and collecting the desorbed contaminants in the contaminant-free fluid as disclosed by Vecitis in order to collect the concentrated contaminants while simultaneously regenerating the carbon nanotube filter [0209] as disclosed by Vecitis
Prakash in view of Holweg and Vecitis does not disclose or make obvious reversing the polarity during this collection/regeneration.
However Seabrook discloses a similar membrane electro filtration [0008]-[0009], [0028]-[0032] wherein “the electric potential may be periodically stopped and reversed to cause movement of a constituent having entered a membrane to move back into the volume or stream from which it came” [0041]
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the method of Prakash in view of Holweg and Vecitis by additionally reversing the polarity during said collection/regeneration as taught by Seabrook as this is another known means to cause the material to desorb from the membrane.
Regarding Claim 24 Prakash in view of Holweg, Vecitis and Seabrook discloses the method of claim 23, but does not disclose wherein the pure draw solution comprises water or sulfuric acid. However, while the contaminant-free fluid is not specifically identified, water would have been an obvious choice because the examples of Prakash use aqueous solutions.
Regarding Claim 26 Prakash in view of Holweg, Vecitis and Seabrook discloses the method of claim 25, and while no specific amount of collection/regeneration contaminant-free fluid is taught, as the amount of contaminant-free fluid passed through would clearly affect how much of the adsorbed material could absorb into it and thus desorb from the membrane, the amount of collection/regeneration contaminant-free fluid passed through is a result effective variable. See MPEP § 2144.05 (B). Case law holds that “discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art.” See In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). In view of this, it would have been obvious to one of ordinary skill in the art to utilize appropriate some of collection/regeneration contaminant-free fluid, including those within the scope of the present claims, so as to produce desired end results including regeneration of the membrane.
Regarding Claim 27 Prakash in view of Holweg, Vecitis and Seabrook discloses the method of claim 25, where the desorbed materials are collected as a concentrated solution for further processing Vecitis [0209] and thus would have been obvious to do in the combined invention, but it is not specifically disclosed that the a precipitated from the pure product stream. However, as they are already concentrated, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the method of Prakash in view of Holweg, Vecitis and Seabrook by subjecting the collected and concentrated desorbed materials to further concentration, such as precipitation, in order to further analyze, process, or store them.
Claims 1-4, 7-11 are rejected under 35 U.S.C. 103 as being unpatentable over US 2017 /0030890 A1 (hereinafter “Holweg”) in view of US 2014/0076728 A1 (hereinafter “Prakash”) and/or US 2022/0396473 A1 (hereinafter “Durupt”, effectively filed 06/15/2021)
Regarding Claim 1 Holweg discloses a membrane nanofiltration system for electrically conductive membrane separation comprising:
a conductive microfiltration membrane filter 150, and which may be formed from etching a silicon wafer, and may thus comprise monolithic silicon having a nanoporous structure, [0053]-[0055] [0066], [0109]-[0117], Figs. 10A-11, 27-29.
an electrical contact in contact with the membrane filter (i.e. to render the membrane an electrode); and
a second (counter) electrode spaced from the membrane 220 (and may be considered to be above a top surface of the membrane filter, since the top of the device is not defined to any particular direction),
and further discloses “applying a voltage between the contact area 138 being electrically connected to the semiconducting or conducting material in the filter part 150 and the sensor electrode 220” and “the electrodes of the first layer 132 and the sensor electrode 220 can be configured into an electrospray for electrostatic fluid delivery induced by dripping for delivery of blood-plasma to the sensor electrode 220, to avoid a clogging of the pores 152 and to minimize the filtration time in comparison to differential-pressure based fluid delivery”; Fig. 14, [0140], and thus the membrane filter, via the electrical contact, and the counter electrode are configured to: generate an electric field between the membrane filter and the counter electrode, hold the membrane filter at a constant electric potential, or flow constant current into the membrane filter, as claimed, and
wherein the membrane filter is configured to separate a component from a mixture solution flowing through the membrane filter into a permeate solution; [0138]-[0141].
Holweg does not disclose the membrane filter has a nanoporous structure with pore sizes ranging from 1 nm to 500 nm.
However, with regard to the microfiltration membrane pore size, the membrane of Holweg may be used for separating elements from blood and more broadly in other separation applications [0138]:
“The feed 610 may be a fluid of medical interest such as blood of a human or an animal. However, the sensor device 300 may be employed also in further fields of biological and chemical analytics. Thus, the microfiltration device 100 may be employed, together with the sensor device 300 in the field of gas sensoric, wherein the microfiltration device 100 constitutes a gas filter or a protection for the sensor 200 from dust particles of a certain size. Furthermore, the sensor device 300 may be employed in analyzing water quality.
Wherein the pore size “depends on the application” [0136], and therefore while it is disclosed the pores “may be a size in a range of 1 µm to 10 µm”, the device is not seen as limited to this pore size because the “may” identifies this range as optional, and no reason is given why pore sizes outside this range would be a problem, particularly for gas or water separation applications which are not discussed in detail; thus the device would not been seen by one of skill in the art to be limited to the optional range disclosed. Also it is noted that for similar electrified membrane separations systems, microfiltration membranes are known to be defined to have pores greater than 0.1 µm (i.e. greater than 100 nm) as disclosed by Prakash.
Further, Durupt additionally discloses a sensor device, wherein a porous protective cover layer is used to cover sensors and protect them against pollution from the environment such as dust [0024], wherein the protective cover layer has pores of an average diameter of from 5 nm to 200 µm, for example 100-300 nm [0027].
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the method of Holweg by forming the pores in the selective membrane layer to have average pore diameters of greater than 100 micron as disclosed by Prakash because this is the known range of pore sizes for microfiltration membranes, and/or in the range 5 nm to 200 micron, or 100-300 nm, as disclosed by Durupt because as taught by Holweg the microfiltration device may be used for gas separations for gas sensors, including specifically as protection for the sensor from dust, and Durupt teaches a pore diameter range that is a desirable and functional pore size range for a membrane when used to protect a sensor from dust, and thus these ranges would therefore be expected to result in forming a successful membrane for use in a sensor device.
With regard to the conductive membrane filter being operable to separate one or more ions from a solution, this is a functional limitation which attempts to define the membrane in terms of its functional abilities, as it is noted that a separation step is not positively recited, thus the prior art need only disclose a membrane capable of the recited functional ability and not the separation of ions from a solution itself, see MPEP 2114.
Since the prior art in combination discloses a conductive, etched silicone filter with pores greater than 100 nm, or from 5 nm to 200 micron, or 100-300 nm, i.e. of the same composition as claimed and disclosed by Applicants, it is asserted, absent evidence to the contrary, that one would reasonably expect that the membrane disclosed by Holweg in view of Prakash and/or Durupt inherently has the same properties as recited. Specifically, it is asserted that the conductive membrane filter is configured to separate one or more ions from a mixture solution flowing through the membrane filter, See MPEP 2112.01.
Since the range(s) disclosed overlaps the range(s) claimed, the range(s) recited in the claim is/are considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range(s) that corresponds to the claimed range. See MPEP 2144.05(I).
Regarding Claims 2-4 Holweg in view of Prakash and/or Durupt discloses the system of claim 1, wherein the mixture is the material worked upon by the apparatus, and thus does not further limit the apparatus, and therefore further limitations to the mixture are not seen to further limit the apparatus of claim 1.
Regarding Claim 7 Holweg in view of Prakash and/or Durupt discloses the system of claim 1, and discloses “applying a voltage between the contact area 138 being electrically connected to the semiconducting or conducting material in the filter part 150 and the sensor electrode 220” and “the electrodes of the first layer 132 and the sensor electrode 220 can be configured into an electrospray for electrostatic fluid delivery induced by dripping for delivery of blood-plasma to the sensor electrode 220, to avoid a clogging of the pores 152 and to minimize the filtration time in comparison to differential-pressure based fluid delivery”; Fig. 14, [0140], therefore the system is configured for electrofiltration and the electric field is applied between the membrane filter and the counter electrode, as claimed.
Regarding Claims 8 and 10 Holweg in view of Prakash and/or Durupt discloses the system of claim 7, where in the pore sizes may be greater than 100 nm, or from 5 nm to 200 micron, or 100-300 nm, supra.
Since the range(s) disclosed overlaps the range(s) claimed, the range(s) recited in the claim is/are considered prima facie obvious. Overlapping ranges are prima facie evidence of obviousness. It would have been obvious to one having ordinary skill in the art to have selected the portion of the disclosed range(s) that corresponds to the claimed range. See MPEP 2144.05(I).
Regarding Claim 9 Holweg in view of Prakash and/or Durupt discloses the system of claim 1, and discloses “applying a voltage between the contact area 138 being electrically connected to the semiconducting or conducting material in the filter part 150 and the sensor electrode 220” and “the electrodes of the first layer 132 and the sensor electrode 220 can be configured into an electrospray for electrostatic fluid delivery induced by dripping for delivery of blood-plasma to the sensor electrode 220, to avoid a clogging of the pores 152 and to minimize the filtration time in comparison to differential-pressure based fluid delivery”; Fig. 14, [0140], therefore the system is configured for electroextraction and the membrane filter is held at a constant electrical potential or has a constant current driven through the membrane filter, as claimed.
Regarding Claim 11 Holweg discloses the system of claim 1, and discloses “applying a voltage between the contact area 138 being electrically connected to the semiconducting or conducting material in the filter part 150 and the sensor electrode 220” and “the electrodes of the first layer 132 and the sensor electrode 220 can be configured into an electrospray for electrostatic fluid delivery induced by dripping for delivery of blood-plasma to the sensor electrode 220, to avoid a clogging of the pores 152 and to minimize the filtration time in comparison to differential-pressure based fluid delivery”; Fig. 14, [0140], therefore the electric field strength and polarity is adjustable to select for the desired component, as claimed.
Response to Arguments
Applicant's arguments filed 12/17/2025 have been fully considered but they are not persuasive.
In response to Applicants’ argument that Holweg only teaches pores with a diameter of 1-10 and teaches away from pores with a diameter less than 1 micron for separating ions and thus it would not have been obvious to use pores smaller than 1 micron in the combined invention of Prakash in view of Holweg; the Examiner disagrees. As noted in the update rejection, in the combined invention, one would use the method and materials of Holweg (monolithic wafer silicon that is etched) to form a membrane suitable for the appatus and processes of Prakash, i.e. having the pore size(s) of the membrane disclosed by Prakash, using etching means known in the art, so the system can achieve the filtration separations as disclosed. Thus it is obvious for the membrane of the combined invention to have pore sizes for microfiltration (pores greater than 0.1 micron), ultrafiltration (pores between 2-100 nm), nanofiltration (pores between 1-2 nm) or reverse osmosis filtration (pores less than 1 nm), Prakash [0034], [0046]-[0048]; i.e. which have pore size ranges which overlap those claimed. While Holweg discloses a membrane for microfiltration, and would thus be obvious to have “pores greater than 0.1 micron” as disclosed by Prakash, the pore size of Holweg not seen to be limiting to the combined invention, since it is not Holweg’s overall apparatus or process that is being modified and there is no teaching away from the pore sizes being in the ranges used by Prakash.
With specific regard to Holweg teaching away, Holweg is clear the device may be used for other applications including gas and liquid separations, not just blood, and that pores size is dependent on the application [0138]. The membrane of Holweg may be used for separating elements from blood so that only a filtrate of the blood, such as plasma, reaches the sensor electrode, among other uses such as for gas filtration and analyzing water quality [0138], and therefore, while in one embodiment the pore are disclosed to be from 1-10 micron, it is also noted that the pores size depends on the application [0136]-[0138], [0159], [0176]-[0179], and no reason is given why pores size less than 1 micron would not be acceptable. Thus there is no teaching away because there is no reason disclosed why pores size less than 1 micron would not be acceptable, and further because Holweg is not the primary reference being used.
In response to Applicants’ argument that Holweg is non-analogous art; the Examiner disagrees. Applicants’ argue that Holweg is directed to blood separation, and therefore non-analogues art. However, as discussed-above, Holweg is clearly not limited to blood separations, but fluid separations more generally. Further, MPEP 2141.01(a), states that “a reference is analogous art to the claimed invention if: (1) the reference is from the same field of endeavor as the claimed invention (even if it addresses a different problem); OR (2) the reference is reasonably pertinent to the problem faced by the inventor (even if it is not in the same field of endeavor as the claimed invention)”. Holweg and Applicants’ invention are all related as to the same field of endeavor, etched silicone membranes for electrified fluid separations, they need not be related further to more specific problems addressed by Applicants'.
Conclusion
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/ERIC J MCCULLOUGH/ Examiner, Art Unit 1773
/BENJAMIN L LEBRON/ Supervisory Patent Examiner, Art Unit 1773
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