Prosecution Insights
Last updated: April 19, 2026
Application No. 18/059,476

Gradient Structures Interfacing Microfluidics and Nanofluidics, Methods for Fabrication and Uses Thereof

Non-Final OA §112§DP
Filed
Nov 29, 2022
Examiner
SIEFKE, SAMUEL P
Art Unit
1758
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Princeton University
OA Round
1 (Non-Final)
63%
Grant Probability
Moderate
1-2
OA Rounds
3y 7m
To Grant
80%
With Interview

Examiner Intelligence

Grants 63% of resolved cases
63%
Career Allow Rate
651 granted / 1031 resolved
-1.9% vs TC avg
Strong +17% interview lift
Without
With
+17.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
36 currently pending
Career history
1067
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
30.1%
-9.9% vs TC avg
§102
47.5%
+7.5% vs TC avg
§112
11.7%
-28.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1031 resolved cases

Office Action

§112 §DP
Notice of Pre-AIA or AIA Status The present application is being examined under the pre-AIA first to invent provisions. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-20 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of U.S. Patent No. 10,551,319. Although the claims at issue are not identical, they are not patentably distinct from each other because US 10,551,310 provides “a surface having a nanofluidic area formed in the surface” while the instant claim 1 requires “a surface having a nanofluidic area formed in the material of the surface”. There is no structural difference between the two claims because a surface is inherently made out a material and the nanofluidic area is formed in that surface made of a material. Therefore the two claims have the same scope. Claim 11 of US 10,551,310 provides a surface having a nanofluidic area formed in the surface while the instant claim 11 requires “a surface having a nanofluidic area formed in the material of the surface”. There is no structural difference between the two claims because a surface is inherently made out a material and the nanofluidic area is formed in that surface made of a material. Therefore the two claims have the same scope. The dependent claims map directed to the instant claims. Claims 1-20 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-11 of U.S. Patent No. 8,333,934 (Cao et al.) in view of US 6,068,752 (Dubrow et al.). Cao discloses a fluidic chip for detecting a property of a macromolecule, comprising: a substrate into or on which are superposed: at least one array of nano scale fluidic structures having a lateral spacing distance between 2 nm to 200 nm and being capable of communicating fluid therethrough, such that at least one property of a macromolecule can be detected when the macromolecule is positioned within or passes through the array of nanoscale fluidic structures; a plurality of microfluidic structures having a lateral spacing distance between 0.5 microns to 5 microns and being capable of communicating fluid therethrough; a gradient interface capable of communicating fluid between the plurality of microfluidic structures and said nanoscale fluidic structures, said gradient interface characterized as having a cross-sectional area, and comprising (a) a plurality of lateral spatial gradient structures therein, wherein the lateral spacings between said gradient structures increase when proximal or adjacent to the at least one microfluidic structure than are the lateral spacings proximal or adjacent to the array of nanoscale fluidic structures, or (b) a vertical slope, such that the vertical spacing proximal or adjacent to the at least one microfluidic structure is increased than is the vertical spacing proximal or adjacent to the array of nanoscale fluidic structures, or (c) both (a) and (b), such that the gradient interface provides for a narrowing of the cross-sectional area of the fluidic structures adjacent to the at least one microfluidic structure to the fluidic structures adjacent to the nanoscale fluidic structures. 2. The fluidic chip of claim 1, wherein said gradient interface comprises branched fluidic channels having reduced lateral distance between adjacent channels toward said nanoscale fluidic structures. 3. A cartridge, comprising at least one fluidic chip of claim 1, said cartridge capable of being inserted and removed from a system for carrying out macromolecular analysis. 4. The fluidic chip of claim 1, wherein: the nanoscale fluidic structures are capable of being or are substantially enclosed by a sealing material surmounting said nanoscale fluidic structures; the plurality of microfluidic structures is capable of being or is substantially enclosed by the sealing material; and the gradient interface is capable of being or is substantially enclosed by the sealing material, and comprising a plurality of gradient structures, the plurality of gradient structures characterized as having a lateral spacing distance relative to each other, and the gradient interface characterized as having a vertical spacing distance relative to the substrate and the sealing material, wherein the lateral spacing distance between the gradient structures, or the vertical spacing distance of the gradient interface, or both, ranges from between 0.5 microns to 5 microns adjacent to said microfluidic structures to between 2 nm to 200 nm adjacent to said nanoscale fluidic structures. 5. The fluidic chip of claim 4, wherein said gradient interface comprises a plurality of gradient structures, and the lateral spacing distance between said gradient structures decreases towards said nanoscale fluidic structures. 6. The fluidic chip of claim 5, wherein said distance between said gradient structures is about 2 nm to about 500 nanometers. 7. The fluidic chip of claim 5, wherein said distance between said gradient structures is in the range of from about 2 nm to about 10 nm. 8. The fluidic chip of claim 5, wherein said distance between said gradient structures is about 2 nm. 9. The fluidic chip of claim 5, wherein said gradient structures range in vertical spacing from about 2 microns adjacent to said microfluidic structures to a vertical spacing ranging from between 2 nm to 500 nm adjacent to said nanoscale fluidic structures. 10. The fluidic chip of claim 5, wherein said gradient structures are branched channels. 11. The fluidic chip of claim 4, wherein said gradient interface decreases in vertical spacing from about 2 microns adjacent to said microfluidic structures to a vertical spacing ranging from between 2 nm to 500 nm adjacent to said nanoscale fluidic structures. Cao (US 8,333,934) does not teach “a sample reservoir capable of receiving a fluid in fluid communication with the microfluidic area”. Dubrow teaches the inclusion of sample reservoirs in a microfluidic device that are capable of receiving a sample fluid, and being in fluid communication with the microfluidic area. (col. 4, third paragraph). It would have been obvious to one having an ordinary skill in the art at the time of the invention to modify the fluidic chip of Cao by including the sample reservoir of Dubrow as the sample reservoir provides a loading position on a microfluidic chip as is well known in the art. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 1 and 11 are indefinite with respect to just which species of “material the “surface” comprises. The specification states “substrate 19 can be a silicon wafer substrate. Alternatively, any type of material compatible with the photolithography can be used as a substrate. It is less than clear as to which materials Applicant considers to be “compatible with photolithography. It is also unclear if the “material” is limited to that known at the time of the filing, or whether it encompasses material that may be have been found or developed at some point subsequent to Applicant’s priority date. Claims 2-10which depend from claim 1, and claims 11-20 which depend from claim 11 fail to overcome this issue and are similarly rejected. The term “about” in claims 3-6, 8-10, 13-16 and 18-20 is a relative term which renders the claims indefinite. The term “about” is not defined by the claims, the specification does not provide a stand for ascertain the degree, and one of ordinary skill in the art would not be know the scope of the invention. See MPEP 2173.05(b) III A. In determining the range encompassed by the term “about,” one must consider the context of the term as it is used in the specification and claims of the application. Ortho-McNeil Pharm., Inc. v. Caraco Pharm. Labs., Ltd., 476 F.3d 1321, 1326, 81 USPQ2d 1427, 1432 (Fed. Cir. 2007). In W.L. Gore & Associates, Inc.v.Garlock, Inc., 721 F.2d 1540, 220 USPQ 303 (Fed. Cir. 1983), the court held that a limitation defining the stretch rate of a plastic as “exceeding about 10% per second” is definite because infringement could clearly be assessed through the use of a stopwatch. However, in another case, the court held that claims reciting “at least about” were invalid for indefiniteness where there was close prior art and there was nothing in the specification, prosecution history, or the prior art to provide any indication as to what range of specific activity is covered by the term “about.” Amgen, Inc. v.Chugai Pharmaceutical Co., 927 F.2d 1200, 18 USPQ2d 1016 (Fed. Cir. 1991). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SAMUEL P SIEFKE whose telephone number is (571)272-1262. The examiner can normally be reached Monday, Tuesday, Thursday, Friday, 8-6. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Maris Kessel can be reached at 571-270-7698. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /SAMUEL P SIEFKE/Primary Examiner, Art Unit 1758
Read full office action

Prosecution Timeline

Nov 29, 2022
Application Filed
Jan 23, 2026
Non-Final Rejection — §112, §DP (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
63%
Grant Probability
80%
With Interview (+17.0%)
3y 7m
Median Time to Grant
Low
PTA Risk
Based on 1031 resolved cases by this examiner. Grant probability derived from career allow rate.

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