DETAILED ACTION
This action is in response to the RCE with amendments and remarks filed 11/26/2025, in which claim 1 has been amended, claims 28-29 have been newly added and claims 1-6, 8-22 and 28-29 are pending and ready for examination.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/26/2025 has been entered.
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 and 16-19 and 28 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 US 2022/0396473 A1 (hereinafter “Durupt”, effectively filed 06/15/2021).
Regarding Claim 1 Holweg discloses a method of making a conductive membrane filter, the method comprising:
etching holes 120 into a conductive surface (which may be of a silicon wafer [0053]-[0055]), wherein the holes do not extend the entire thickness of the membrane; and
etching pores 152 to extend from the holes to an opposite surface of the wafer, producing a selective membrane layer 150 between the end of the holes and an opposite surface of the wafer,
wherein the pores in the selective membrane layer are smaller than the size of the holes in the silicon wafer; Figs. 10A-11, [0109]-[0117], multiple holes shown in Fig. 27-29.
Holweg does not disclose wherein the pores in the selective membrane layer have a diameter of about 1 nm to 500 nm or wherein the conductive membrane filter is operable to separate one or more ions from a solution.
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 operable to separate one or more ions from a solution See MPEP 2112.01.
Regarding Claim 2 Holweg in view of Prakash and/or Durupt discloses the method of claim 1, wherein the holes in the silicon wafer are etched using deep reactive ion etching; Holweg [0113].
Regarding Claim 3 Holweg in view of Prakash and/or Durupt discloses the method of claim 2, further comprising using an etching mask in the deep reactive ion etching to control a geometry (and therefore also the density) of the holes in the silicon wafer Holweg [0113], wherein the masking layer may be SiO2 Holweg [0095].
Regarding Claim 4 Holweg in view of Prakash and/or Durupt discloses the method of claim 3, wherein no gap is disclosed between the SiO2 etching mask and the silicon wafer range, and is thus inherently 0 μm; Holweg Figs. 10A-11, [0109]-[0117].
Regarding Claim 16 Holweg in view of Prakash and/or Durupt discloses the method of claim 1, wherein the holes in the silicon wafer are discleod to be rectangular and have a length from 10-1000 microns [0152]. Though circular holes (i.e. with a diameter) are not specially disclosed, this would involve a simple change in shape which would have been obvious for use in applications requiring circular membranes such as in order to fit circular membrane holders.
Regarding Claim 17 Holweg in view of Prakash and/or Durupt discloses the method of claim 1, wherein the holes in the silicon wafer have a depth (H2) of 100 nm to 20 micron Holweg [0152].
Regarding Claim 18 Holweg in view of Prakash and/or Durupt discloses the method of claim 1, wherein the substrate/silicon wafer has a thickness of 30-1000 micron Holweg [0079].
Since the range disclosed overlaps the range claimed, the range recited in the claim is 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 that corresponds to the claimed range. See MPEP 2144.05(I).
Regarding Claim 19 Holweg in view of Prakash and/or Durupt discloses the method of claim 1, wherein the silicon wafer is conductive or semiconductive Holweg [0055],[0065], and thus may inherently have a resistivity in the range claimed, as semiconductors are well-known to have a resistivity range from 10-4 to 108 cm-ohm.
Since the range disclosed overlaps the range claimed, the range recited in the claim is 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 that corresponds to the claimed range. See MPEP 2144.05(I).
Regarding Claim 28 Holweg in view of Prakash and/or Durupt discloses the method of claim 1, wherein it is noted that the separation step and thus the solution are not positively recited and are functional limaitons, thus further limitations to the solution are functional, see MPEP 2114. Further, 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 operable to separate one or more ions from an acidic solution See MPEP 2112.01.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Holweg in view of Prakash and/or Durupt further in view of F. Laerme, et al, "Bosch deep silicon etching: improving uniformity and etch rate for advanced MEMS applications," Technical Digest. IEEE International MEMS 99 Conference. Twelfth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.99CH36291), Orlando, FL, USA, 1999, pp. 211-216, doi: 10.1109/MEMSYS.1999.746812. (hereinafter “Laerme”).
Regarding Claim 5 Holweg in view of Prakash and/or Durupt discloses the method of claim 2, wherein a conventional Bosch process is used to perform a fast, anisotropic etch at rates ranging from about 1 μm/min to 30 μm/min.
However Laerme discloses Bosch deep silicon etching using reactive ions is a known means for anisotropic etching silicon in MEMS applications achieving high etch rates of 6 microns/min and improved etch uniformity; Abstract, Results, Conclusions
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 in view of Prakash and/or Durupt by using to form the holes the Bosch deep silicon etching process disclosed by Laerme because involves the simple substitution of known deep reactive ion etching processes used for silicon to obtain the predictable result of forming deep cavities in silicon, and because the Bosch process results in high etch rates and improved etch uniformity.
Claims 6 and 8-10 are rejected under 35 U.S.C. 103 as being unpatentable over Holweg in view of Durupt further in view of US 2019/0312112 A1 (hereinafter “Smith”).
Regarding Claims 6 and 8 Holweg in view of Prakash and/or Durupt discloses the method of claim 1, but does not disclose (claim 6) wherein the pores in the selective membrane layer are etched using MACE, or (claim 8) further comprising sputtering the silicon wafer with metal catalyst nanoparticles.
However Smith discloses a method of forming pores in a semiconductor (silicon) material using metal-assisted chemical etching (MACE), wherein the semiconductor (such as a silicon wafer) is sputtered with metal catalyst nanoparticles in order to direct etching of pores from the nanoparticles [0131]-[0132], [0141], [0145], [0163]-[0168].
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 in view of Prakash and/or Durupt by forming the pores in the membrane via the MACE process of Smith which involves sputtering the silicon wafer with metal catalyst nanoparticles, because this involves the simple substitution of known means for forming pores in a silicon membrane via etching to obtain the predictable result of forming pores in silicon to create a membrane.
Regarding Claim 9 Holweg in view of Smith and Prakash and/or Durupt discloses the method of claim 8, wherein the metal catalyst nanoparticles comprise silver (Ag), gold (Au), or platinum (Pt); Smith [0135].
Regarding Claim 10 Holweg in view of Smith and Prakash and/or Durupt discloses the method of claim 8, wherein the metal catalyst nanoparticles have a diameter of about 2 nm or 4.4 nm Smith [0168].
Claims 11-15 are rejected under 35 U.S.C. 103 as being unpatentable over Holweg in view of Smith and Prakash and/or Durupt and further in view of Rickard Gunnarsson, Iris Pilch, Robert D. Boyd, Nils Brenning, Ulf Helmersson; The influence of pressure and gas flow on size and morphology of titanium oxide nanoparticles synthesized by hollow cathode sputtering. J. Appl. Phys. 28 July 2016; 120 (4): 044308. (hereinafter “Gunnarsson”)
Regarding Claim 11-13 Holweg in view of Smith and Prakash and/or Durupt discloses the method of claim 8, but does not disclose (claim 11) wherein the sputtering occurs in a chamber at a base pressure of about 6 x 10-4 Torr, (Claim 12) wherein Argon (Ar) gas is introduced into the chamber after approximately 5 minutes of vacuum pump-down, then increased from about 5 to 12 seem, or (claim 13) wherein the chamber is then maintained at a pressure of about 5 mTorr to 30 mTorr.
However Gunnarsson discloses the pressure and gas flow used during sputtering effect the formed nanoparticles morphology and size (at least Title, Abstract, Conclusions).
Sputtering chamber base pressure, sputtering argon pressure and argon flow, as well as pump down pressure, are thus variables which achieve a recognized result, and it would therefore have been obvious for one of skill in the art to optimize these variables 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).
Regarding Claim 14 Holweg in view of Smith, Gunnarsson, and Prakash and/or Durupt discloses the method of claim 13, wherein a power applied to the silicon wafer during sputtering may be 15 W, 30 W, 45 W (Smith Table 1, [0208]-[0209]) or 150 W, [0165].
Regarding Claim 15 Holweg in view of Smith, Gunnarsson, and Prakash and/or Durupt discloses the method of claim 14, wherein sputter deposition times may be 2 or 4 seconds; Table 1, [0208]-[0209].
Claims 20-22 are rejected under 35 U.S.C. 103 as being unpatentable over Holweg in view of Prakash and/or Durupt further in view of US 2016/0158706 A1 (hereinafter “Wang”).
Regarding Claims 20-22 Holweg in view of Prakash and/or Durupt discloses the method of claim 1, but does not disclose further comprising depositing a layer comprising a metal oxide on the selective membrane layer of the silicon wafer through atomic layer deposition (ALO).
However Wang discloses a method for forming a membrane having a silicon substrate formed via etching, wherein the membrane’s pores are coated in a material via atomic layer deposition (ALD), which may be 1 nm to 10 microns thick and comprise the metal oxides TiO2 or Al2O3, in order to control the pore size of the membrane via narrowing the pores by the metal oxide coating “in order to adjust the size of pores according to the application” [0027]-[0028], [0045].
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 in view of Prakash and/or Durupt by including a 1 nm to 10 microns thick TiO2 or Al2O3 layer deposited on the membrane via ALD as disclosed by Wang in order to adjust the size of pores according to the application.
Claim 29 is rejected under 35 U.S.C. 103 as being unpatentable over Holweg in view of Smith, and Prakash and/or Durupt.
Regarding Claim 29 Holweg discloses a method of making a conductive membrane filter, the method comprising:
etching holes 120 into a conductive surface (which may be of a silicon wafer [0053]-[0055]), wherein the holes do not extend the entire thickness of the membrane; and
etching pores 152 to extend from the holes to an opposite surface of the wafer, producing a selective membrane layer 150 between the end of the holes and an opposite surface of the wafer,
wherein the pores in the selective membrane layer are smaller than the size of the holes in the silicon wafer; Figs. 10A-11, [0109]-[0117], multiple holes shown in Fig. 27-29.
Holweg does not disclose (1) the etching of the pores is by metal-assisted chemical etching or (2) wherein the pores in the selective membrane layer have a diameter of about 1 nm to 500 nm or (3) wherein the conductive membrane filter is operable to separate one or more ions from an acidic solution.
However, with regard to (1) 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 (2) metal-assisted chemical etching, Smith discloses a method of forming pores in a semiconductor (silicon) material using metal-assisted chemical etching (MACE), wherein the semiconductor (such as a silicon wafer) is sputtered with metal catalyst nanoparticles in order to direct etching of pores from the nanoparticles, in order to form pores less than 15 nm [0131]-[0132], [0141], [0145], [0163]-[0168].
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 pores in the membrane via the MACE process of Smith which involves sputtering the silicon wafer with metal catalyst nanoparticles, because this involves the simple substitution of known means for forming pores in a silicon membrane via etching to obtain the predictable result of forming pores in silicon to create a membrane. Since Smith discloses the pores formed are less than 15 nm it would therefore have been obvious to use pore ranges of from 5-15 nm, i.e. a smaller subset of the ranges disclosed by Durupt when used as s protective cover.
With regard to (3) the conductive membrane filter being operable to separate one or more ions from an acidic 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, MACE etched silicone filter with pores from 5-15 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 Smith and Prakash and/or Durupt inherently has the same properties as recited. Specifically, it is asserted that the conductive membrane filter is operable to separate one or more ions from an acidic solution See MPEP 2112.01.
Claims 1-4, 6, 8-10, 16-19 and 28-29 are rejected under 35 U.S.C. 103 as being unpatentable over Smith in view of Holweg.
Regarding Claims 1 and 29 Smith discloses a method of making a silicon (i.e. inherently conductive) membrane filter, the method comprising
thinning a commercial silicon wafer, then etching pores using metal assisted chemical etching to extend from one surface to an opposite surface of the silicon wafer, producing a selective membrane layer between the opposing surfaces of the wafer, [0131]-[0132], [0141], [0145], [0163]-[0168], [0201],
wherein the pores in the selective membrane layer have a diameter of less than 15 nm [0143], or less than 20 nm (claim 1).
Smith does not disclose (1) first etching holes into the surface of the silicon wafer, wherein the holes do not extend the entire thickness of the membrane; and then etching the pores to extend from the holes to an opposite surface of the wafer, or (2) the conductive membrane filter being operable to separate one or more ions from an acidic solution.
However Holweg discloses a method of making a conductive membrane filter, the method comprising:
etching holes 120 into a conductive surface (which may be of a silicon wafer [0053]-[0055]), wherein the holes do not extend the entire thickness of the membrane; and
etching pores 152 to extend from the holes to an opposite surface of the wafer, producing a selective membrane layer 150 between the end of the holes and an opposite surface of the wafer,
wherein the pores in the selective membrane layer are smaller than the size of the holes in the silicon wafer; Figs. 10A-11, [0109]-[0117], multiple holes shown in Fig. 27-29 for multi-sensor devices.
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 Smith by instead of thinning the whole wafer before forming pores, etching holes into sections of the wafer, then etching pores to extend from the holes to an opposite surface of the wafer as disclosed by Holweg because this involves the simple substitution of known an alternative means for forming a thin porous silicone membrane from a thicker wafer to obtain the predictable result of forming a successful silicon membrane, and because this allows the membrane to comprise an integral substrate layer which supports the membrane, and allows for multiple membrane to be formed on one wafer, such as for use in multi-sensor devices.
With regard to (2) the conductive membrane filter being operable to separate one or more ions from an acidic 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, MACE etched silicone filter with pores from less than 20 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 Smith in view of Holweg inherently has the same properties as recited. Specifically, it is asserted that the conductive membrane filter is operable to separate one or more ions from an acidic solution See MPEP 2112.01.
Regarding Claim 2 Smith in view of Holweg discloses the method of claim 1, wherein the holes in the silicon wafer are etched using deep reactive ion etching; Holweg [0113].
Regarding Claim 3 Smith in view of Holweg discloses the method of claim 2, further comprising using an etching mask in the deep reactive ion etching to control a geometry (and therefore also the density) of the holes in the silicon wafer Holweg [0113], wherein the masking layer may be SiO2 Holweg [0095].
Regarding Claim 4 Smith in view of Holweg discloses the method of claim 3, wherein no gap is disclosed between the SiO2 etching mask and the silicon wafer range, and is thus inherently 0 μm; Holweg Figs. 10A-11, [0109]-[0117].
Regarding Claim 6 Smith in view of Holweg discloses the method of claim 1, wherein the pores in the selective membrane layer are etched using MACE, Smith [0131]-[0132], [0141], [0145], [0163]-[0168], [0201].
Regarding Claim 8 Smith in view of Holweg discloses the method of claim 1, comprising sputtering the silicon wafer with metal catalyst nanoparticles in order to direct etching of pores from the nanoparticles, Smith [0131]-[0132], [0141], [0145], [0163]-[0168], [0201].
Regarding Claim 9 Smith in view of Holweg discloses the method of claim 8, wherein the metal catalyst nanoparticles comprise silver (Ag), gold (Au), or platinum (Pt); Smith [0135].
Regarding Claim 10 Smith in view of Holweg discloses the method of claim 8, wherein the metal catalyst nanoparticles have a diameter of about 2 nm or 4.4 nm Smith [0168].
Regarding Claim 16 Smith in view of Holweg discloses the method of claim 1, wherein the holes in the silicon wafer are discleod to be rectangular and have a length from 10-1000 microns Holweg [0152]. Though circular holes (i.e. with a diameter) are not specially disclosed, this would involve a simple change in shape which would have been obvious for use in applications requiring circular membranes such as in order to fit circular membrane holders.
Regarding Claim 17 Smith in view of Holweg discloses the method of claim 1, wherein the holes in the silicon wafer have a depth (H2) of 100 nm to 20 micron Holweg [0152].
Regarding Claim 18 Smith in view of Holweg discloses the method of claim 1, wherein the substrate/silicon wafer has a thickness of 275 +/- 25 micron Smith [0155], [0165]
Regarding Claim 19 Smith in view of Holweg discloses the method of claim 1, wherein the silicon wafer has a range of silicon resistivities of 0.001-0.01 cm-ohm Smith [0155]
Regarding Claim 28 Smith in view of Holweg discloses the method of claim 1, wherein it is noted that the separation step and thus the solution are not positively recited and are functional limaitons, thus further limitations to the solution are functional, see MPEP 2114. Further, since the prior art in combination discloses a conductive, etched silicone filter with pores of less than 20 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 Smith in view of Holweg inherently has the same properties as recited. Specifically, it is asserted that the conductive membrane filter is operable to separate one or more ions from an acidic solution See MPEP 2112.01.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Smith in view of Holweg further in view of F. Laerme, et al, "Bosch deep silicon etching: improving uniformity and etch rate for advanced MEMS applications," Technical Digest. IEEE International MEMS 99 Conference. Twelfth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.99CH36291), Orlando, FL, USA, 1999, pp. 211-216, doi: 10.1109/MEMSYS.1999.746812. (hereinafter “Laerme”).
Regarding Claim 5 Smith in view of Holweg discloses the method of claim 2, wherein a conventional Bosch process is used to perform a fast, anisotropic etch at rates ranging from about 1 μm/min to 30 μm/min.
However Laerme discloses Bosch deep silicon etching using reactive ions is a known means for anisotropic etching silicon in MEMS applications achieving high etch rates of 6 microns/min and improved etch uniformity; Abstract, Results, Conclusions
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 Smith in view of Holweg by using to form the holes the Bosch deep silicon etching process disclosed by Laerme because involves the simple substitution of known deep reactive ion etching processes used for silicon to obtain the predictable result of forming deep cavities in silicon, and because the Bosch process results in high etch rates and improved etch uniformity.
Claims 11-15 are rejected under 35 U.S.C. 103 as being unpatentable over Smith in view of Holweg and further in view of Rickard Gunnarsson, Iris Pilch, Robert D. Boyd, Nils Brenning, Ulf Helmersson; The influence of pressure and gas flow on size and morphology of titanium oxide nanoparticles synthesized by hollow cathode sputtering. J. Appl. Phys. 28 July 2016; 120 (4): 044308. (hereinafter “Gunnarsson”)
Regarding Claim 11-13 Smith in view of Holweg discloses the method of claim 8, but does not disclose (claim 11) wherein the sputtering occurs in a chamber at a base pressure of about 6 x 10-4 Torr, (Claim 12) wherein Argon (Ar) gas is introduced into the chamber after approximately 5 minutes of vacuum pump-down, then increased from about 5 to 12 seem, or (claim 13) wherein the chamber is then maintained at a pressure of about 5 mTorr to 30 mTorr.
However Gunnarsson discloses the pressure and gas flow used during sputtering effect the formed nanoparticles morphology and size (at least Title, Abstract, Conclusions).
Sputtering chamber base pressure, sputtering argon pressure and argon flow, as well as pump down pressure, are thus variables which achieve a recognized result, and it would therefore have been obvious for one of skill in the art to optimize these variables 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).
Regarding Claim 14 Smith in view of Holweg and Gunnarsson discloses the method of claim 13, wherein a power applied to the silicon wafer during sputtering may be 15 W, 30 W, 45 W (Smith Table 1, [0208]-[0209]) or 150 W, [0165].
Regarding Claim 15 Smith in view of Holweg and Gunnarsson discloses the method of claim 14, wherein sputter deposition times may be 2 or 4 seconds; Table 1, [0208]-[0209].
Claims 20-22 are rejected under 35 U.S.C. 103 as being unpatentable over Smith in view of Holweg in view of US 2016/0158706 A1 (hereinafter “Wang”).
Regarding Claims 20-22 Smith in view of Holweg discloses the method of claim 1, but does not disclose further comprising depositing a layer comprising a metal oxide on the selective membrane layer of the silicon wafer through atomic layer deposition (ALO).
However Wang discloses a method for forming a membrane having a silicon substrate formed via etching, wherein the membrane’s pores are coated in a material via atomic layer deposition (ALD), which may be 1 nm to 10 microns thick and comprise the metal oxides TiO2 or Al2O3, in order to control the pore size of the membrane via narrowing the pores by the metal oxide coating “in order to adjust the size of pores according to the application” [0027]-[0028], [0045].
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 Smith in view of Holweg by including a 1 nm to 10 microns thick TiO2 or Al2O3 layer deposited on the membrane via ALD as disclosed by Wang in order to adjust the size of pores according to the application.
Response to Arguments
Applicant's arguments filed 11/26/2025 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; the Examiner disagrees. 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.
In response to Applicants’ argument that Holweg is non-analogous art; the Examiner disagrees. Applicants’ argue that Holweg is directed to blood separation, which is “a fundamentally different mechanism” from the “charge-selective electrochemical transport” filtration process disclosed by Applicants, however claim 1 is to a method of making a conductive membrane, not to a method of filtration and does not recite “charge-selective electrochemical transport” as a use of the membrane formed from the method of claim 1. 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 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