DETAILED ACTION
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 .
Response to Amendment
Applicant’s amendment dated 6/10/2026 has added new claims 16 and 17. Claims 1-17 are pending in the application. The 112(b) rejection previously set forth over claims 1-15 is withdrawn in view of the amendment.
The double patenting rejection previously set forth over copending application 18/390,262 are withdrawn in view of the Terminal Disclaimer filed and approved 6/10/2026.
Response to Arguments
Applicant's arguments filed 6/10/2026 have been fully considered but they are not persuasive. Applicant’s arguments regarding the rejection of claims 4-6 as it would apply to amended claim 1 are not persuasive, because in response to applicant's argument that Tang does not teach shrinking of the pore, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985). Tang clearly contemplates coating the interior of pores (see e.g. [Fig. 12]) and the instant specification makes clear [pg. 8, lines 3-13] that such surface modification of a pore is one of the methods of achieving the claimed pore shrinking. As such, even if Tang teaches modification for purposes other than shrinking of pores, the fact that Tang teaches adding material to the inner surface of pores would inherently cause some degree of shrinking and is, regardless, consistent with the methods of shrinking contemplated by the instant invention.
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 (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
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 1-7, 10, 11, 13, 14, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Black et al (US PGPub 2004/0124092 A1) in view of Tang et al (US PGPub 2010/0181288 A1) and Zhang et al (US PGPub 2011/0042301 A1).
With respect to claim 1, Black teaches a method of forming an inorganic porous membrane [Abs] which is contemplated within the field of biomedical applications including filtration of proteins, viruses, and the like [0004]; whether the filter is actually used as a blood filter is drawn to the intended use of the product of the claimed process, and does not limit the process steps for making the product.
Black teaches forming the membrane by providing a first layer (membrane layer) and forming a mask on the membrane layer by, in an embodiment, forming a layer of self-assembled particles of a block copolymer, and subsequently forming pores in the block copolymer by removing a portion of the block copolymer [0008, 0021]. After converting the polymer layer into a mask, the underlying membrane layer is etched through the mask for form uniformly-sized, densely packed pores [0026-0027, Figs. 2A-C & 3]. Black teaches that the pores formed in the polymer layer (and hence the pores etched into the membrane) may be adjusted down to only a few nanometers by appropriate material selection, with high uniformity [0020] which would be understood to satisfy a requirement of less than 20 nm. Additionally or alternatively, Black discloses typical diameters of around 20 nm, and ranges available from 2-100 nm [0021] for particular diblock copolymer systems, which further at minimum render the claimed pore size obvious to one of ordinary skill in the art.
Applicant amended to require that the process includes a pore shrinking step; examiner notes that the instant specification makes clear that pore shrinking is accomplished in one of three exemplary ways [pg. 8 lines 3-13]: via addition of a polymer brush layer, via deposition of a film on the inner surface, or via oxidation of the inner surface. Black is silent to such a step.
However, Tang teaches similar micro- and nano-porous filters e.g. formed through making an lithography techniques [Abs] and teaches that it may be desirable to modify the surface conditions of the membranes e.g. by coating the surface and pore interiors with suitable polymer layers [0074-0075]. However, this is taught within the context of polymeric substrates.
Additionally, Zhang teaches that copolymer brushes can be attached to the surface of an inorganic membrane material using a suitable oxide intermediate e.g. silicon dioxide [0035-0036]. However, this is taught within the context of forming mask layers or the like for etching.
It would have been obvious to one of ordinary skill in the art in view of the combined teachings of Tang and Zhang to modify the process of Black to feature formation of an intermediate oxide layer and grafting thereto of polymer brushes or a similar coating layer to modify the surface and/or the pore interiors of the resulting etched membrane, and thus (whether intentionally or incidentally) to shrink the pores; in view of Tang, it would be recognized that this can be carried out in order to modify the membrane to provide more favorable surface properties (e.g. suitable for bioseparations) and, in view of Zhang, it would be recognized that this set of process steps can be adapted for modifying an inorganic substrate with polymer grafts e.g. brushes.
With respect to claims 2 and 3, Black teaches supporting layers in which larger pores are formed via backside etching [Figs. 4A-H & 5A-H] such that the nano-scale layer is suspended on a support of silicon or the like [0028-0029]. This is properly forming a channel through [a] substrate with the first layer provided above the substrate.
These channels extend through the substrate in a direction orthogonal to the first layer i.e. perpendicular to the first layer, passing through it in a thickness direction, with the second end arranged at a bottom of the substrate.
With respect to claims 4-6, Black teaches as above but is silent to a step of depositing a film or oxidizing the inner surfaces of the pores of the first layer.
However, Tang teaches similar micro- and nano-porous filters e.g. formed through making an lithography techniques [Abs] and teaches that it may be desirable to modify the surface conditions of the membranes e.g. by coating the surface and pore interiors with suitable polymer layers [0074-0075]. However, this is taught within the context of polymeric substrates.
Additionally, Zhang teaches that copolymer brushes can be attached to the surface of an inorganic membrane material using a suitable oxide intermediate e.g. silicon dioxide [0035-0036]. However, this is taught within the context of forming mask layers or the like for etching.
It would have been obvious to one of ordinary skill in the art in view of the combined teachings of Tang and Zhang to modify the process of Black to feature formation of an intermediate oxide layer and grafting thereto of polymer brushes or a similar coating layer to modify the surface and/or the pore interiors of the resulting etched membrane; in view of Tang, it would be recognized that this can be carried out in order to modify the membrane to provide more favorable surface properties (e.g. suitable for bioseparations) and, in view of Zhang, it would be recognized that this set of process steps can be adapted for modifying an inorganic substrate with polymer grafts e.g. brushes.
With respect to claim 7, Black teaches that the mask can be formed by depositing a PS-PMMA diblock copolymer, such that the PMMA forms cylinders which can be made to orient vertically and then be removed, thereby facilitating pore formation [0021].
With respect to claim 10, Black teaches that membrane pore densities in excess of 109-1012/cm2 are achievable [0020], such that maximization of the fill-factor is at least a contemplated benefit of the taught process; examiner notes that for a pore diameter of about 20 nm, a fill-factor of 40% is understood to require on the order of 3x1011 pores/cm2, such that the fill-factors implied by Black’s contemplated range of densities would at minimum overlap the claimed range for fill-factor. The claimed value would therefore have been obvious to one of ordinary skill in the art e.g. given the overlapping range or, otherwise, given the motivation to optimize the packing density of the pores already contemplated by Black.
With respect to claim 11, Black teaches as above but is silent to the thickness of the membrane layer (i.e. the first layer).
However, Zhang teaches similar inorganic membrane devices [Abs] which is formed in part using a pore forming layer of a block copolymer [0024], and teaches that for certain biomedical applications such as virus filtration, nanoscale pores of e.g. 15 nm and membrane thickness of about 100 nm are desirable in order to give the required separation and flux properties [0013].
It would have been obvious to one of ordinary skill in the art to provide a similar thickness to the membrane produced by the process of Black because, as in Zhang, such a thickness gives useful flux for filters in the biomedical field.
With respect to claim 13, as above the copolymer system may be PS-PMMA diblock copolymer.
With respect to claim 14, Black teaches that selection of appropriate molecular weights and ratios is a result-effective variable which can be used to control the pore size of the copolymer mask (and thus the underlying membrane via etching) [0021]. See MPEP 2144.05 II.A: “’[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.’ In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).” The claimed range would have been obvious as an optimization of the result-effective variable discussed by Black.
With respect to claim 16, as above Black suggests ranges of 2-100 nm are available as pore sizes, which overlaps the claimed range and thus renders it obvious to one of ordinary skill in the art.
Claims 8, 15, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Black et al in view of Tang et al and Zhang et al, further in view of Bosworth et al (US PGPub 2011/0151236 A1).
With respect to claim 8, Black teaches as above but is silent to embodiments in which the block copolymer forms lamellar domains to form a plurality of slits in the membrane when etched.
However, Bosworth teaches similar processes for forming membranes using block copolymer lithography [Abs] using selectively degraded block copolymers as masks to etch pores into underlying substrates; membranes for e.g. microfluidic applications are contemplated [0008]. Bosworth teaches that copolymers can be provided typically in cylindrical or lamellar configurations [0002] e.g. with or without chemical pre-patterning, including with PS-PMMA copolymer [0046, Fig. 3] which allows for natural or controlled alignment of the lamella to occur, thus producing straight or curved slits [0061]. See MPEP 2143 I.B; a simple substitution of one known copolymer configuration for another, known to be useful for forming masks for etching in production of membranes useful for e.g. filtration, is obvious to one of ordinary skill in the art.
With respect to claim 15, see the rejections of claims 1 and 8 above; at least the combination of Black and Bosworth would produce filtration membrane comprising a first layer with pores below 20 nm in embodiments, and where such pores may include curved slits (in particularly the ”fingerprint”-like patterns discussed by Bosworth regarding uncontrolled alignment of lamellar). Whether such a filter represents specifically a blood filter is drawn to the intended use of the claimed device and does not distinguish structurally, and as discussed above Black already teaches suitability for various biomedical applications. Alternatively, if such limitation is intended to imply particular structure, in view of Tang the use of such filters for applications such as hemodialysis would have been obvious to one of ordinary skill in the art [Abs, 0003].
With respect to claim 17, as above Black suggests ranges of 2-100 nm are available as pore sizes, which overlaps the claimed range and thus renders it obvious to one of ordinary skill in the art.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Black et al in view of Tang et al and Zhang et al, further in view of Yoo et al (US PGPub 2016/0059190 A1).
Black teaches as above but is silent to the production of tapered pores within the first layer.
However, Yoo teaches liquid filtering structures with high filtration efficiency [Abs] using a nanoporous layer, including layers formed via etching [0120], and teaches that the nanopore itself may have e.g. a tapered or bottleneck shape to obtain a minimum diameter of 10 nm or less [0061], such that functionalization when present may be provided only at the point of narrowest diameter. See further MPEP 2144.04 IV.B; changes in shape are generally obvious to those of ordinary skill in the art. The use of tapered pores such as those taught by Yoo in the process of Black would have been obvious e.g. as a standard configuration for pores, or to gain a benefit such as reducing the region for which the diameter is minimized and functionalization is warranted.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Black et al in view of Tang et al and Zhang et al, further in view of Holweg et al (US PGPub 2017/0030890 A1).
Black teaches as above but is silent to the first layer/substrate including an integrated circuit.
However, Holweg teaches similar filtration devices formed from semiconductor substrates [Abs] and teaches integrating them with substrates containing application-specific integrated circuits which allow for the filters to be combined into sensor applications, e.g. for blood parameter monitoring (glucose levels or the like) [0144].
It would have been obvious to include a similar ASIC structure in the product produced by Black’s method for the same purpose i.e. to allow for production of filters useful in biosensors of various application, as suggested by Holweg.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRADLEY R SPIES whose telephone number is (571)272-3469. The examiner can normally be reached Mon-Thurs 8AM-4PM.
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/BRADLEY R SPIES/Primary Examiner, Art Unit 1776
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