Prosecution Insights
Last updated: May 29, 2026
Application No. 17/176,561

FLOW CELLS UTILIZING SURFACE-ATTACHED STRUCTURES, AND RELATED SYSTEMS AND METHODS

Non-Final OA §103
Filed
Feb 16, 2021
Priority
Sep 18, 2015 — provisional 62/220,906 +4 more
Examiner
MUI, CHRISTINE T
Art Unit
1797
Tech Center
1700 — Chemical & Materials Engineering
Assignee
The University of North Carolina at Chapel Hill
OA Round
5 (Non-Final)
78%
Grant Probability
Favorable
5-6
OA Rounds
0m
Est. Remaining
98%
With Interview

Examiner Intelligence

Grants 78% — above average
78%
Career Allowance Rate
1072 granted / 1369 resolved
+13.3% vs TC avg
Strong +20% interview lift
Without
With
+20.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
57 currently pending
Career history
1429
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
81.3%
+41.3% vs TC avg
§102
13.4%
-26.6% vs TC avg
§112
2.3%
-37.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1369 resolved cases

Office Action

§103
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 . 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 29 APRIL 2026 has been entered. Status of Claims The claim set submitted on 29 APRIL 2026 is acknowledged and considered. In the claim set, Claims 1-93, 106, 108-118 are ‘Cancelled’; Claims 94-105, 107, 119-125 are ‘Previously Presented’; and Claims 126-127 are ‘New’. Current pending claims are Claims 94-105, 107 and 119-127 and are considered on the merits below. 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 94-105, 107 and 119-127 are rejected under 35 U.S.C. 103 as being unpatentable over TONER, US Patent 8,304,230 B2, submitted on the Information Disclosure Statement on 16 FEBRUARY 2021; US Patents Cite No. 1, in view of EVANS, Magnetically Actuated Nanorod Arrays as Biomimetic Cilia, Nano Letters, 2007, Vol. 7, No. 5, page 1428-1434. Applicant’s invention is drawn towards a method. Regarding Claim 94, the reference TONER discloses a method for extracting a target from a sample, abstract, separating cells from a sample, the method comprising: flowing a target-containing sample through a flow cell comprising a fluid inlet and a fluid outlet and a chamber therebetween, and into contact with surface- attached structures disposed in the chamber of the flow cell, Figure 7, 8 and 17, Column 11 line 9-37, perfuse a mixture of cells through microfluidic device though inlet, Column 13 line 17-34, inlet for accepting blood / outlet for collection microfluidic device includes obstacles through flow chamber, wherein the surface- attached structures are attached to an inside surface of the flow cell at a plurality of respective attachment sites, Figure 8, Column 11 line 14-37, obstacles are in ordered array or randomly through flow chamber; applying actuation to the interior of the flow cell to actuate movement while flowing the target-containing sample through the chamber of the flow cell, Column 2 line 66-Column 3 line 8, Column 16 line 14-17, Column 17 line 43-45, wherein the actuation prevents or disrupts clogging of the sample material as it flow through the chamber, Column 18 line 17-22, 55-64; and isolating the target of the target-containing sample from a remaining portion of the sample through an interaction between the target and the at least one of the surface -attached structures, Column 17 line 43-45, Column 2 line 59-63, Column 10 line 56-65, and wherein the interaction comprises binding or capturing the target to at least one of the surface-attached structures, Claims 8, 9, 15, 16, selective binding, Column 2 line 38-39, 59-61, Column 3 line 38-51, Column 11 line 24-37, Column 15 line 22-26 and Column 16 line 3-6, capture of specific population of cells expressing certain surface model. The TONER reference discloses the claimed invention, but is silent in regards to application of a magnetic or electric field to the interior of the flow cell to actuate movement of one or more of the surface-attached structures relative to the attachment sites. The EVANS reference discloses a method, comprising: providing surface-attached structures disposed in a flow cell, Figure 1 and 2, pages 1429-1430, the flow cell is interpreted to be the space between the PDMS spacers, where fluid flow is to be investigated, page 1430, investigate fluid flow include by actuation of rod array, wherein the surface-attached are attached to an inside surface of the flow cell at a plurality of respective attachment sites, Figure 1 and 2, page 1429, nanorod array are attached to a glass slide / coverslip; applying a magnetic actuation filed to the interior of the flow cell to actuate movement of one or more of the surface-attached structures relative to the attachment sites, Figure 2-6, page 1430, wherein actuation of the one or more of the surface-attached structures is capable to prevent or disrupts clogging of sample material as it flow through the chamber. EVANS discloses the fabricated nanorod array are to act as biomimetic cilia. It is known in the art that biomimetic cilia are engineered structures designed to mimic the beating motion of natural cilia, which are used by many organisms to move fluids efficiently at microscopic scales. Therefore, it is expected that the nanorod array that are taught by EVANS would prevent or disrupt clogging when the fluid flow in the space between the PDMS spaces are investigated. Thus, it would be obvious to one having ordinary skill in the art before the effective filing date to modify the TONER reference to include the nanorod arrays actuated by a magnetic field as taught by EVANS to study the mechanics of nanoscale fluid flow in a ciliated system, to prevent sedimentation of fluids within the fluid cell as well as to prevent or disrupts clogging of sample material as it flow through the chamber. Additional Disclosures Included are: Claim 95: wherein the method of claim 94, wherein isolating the target comprises binding the target to a binding agent disposed in the flow cell; wherein the binding agent is selected from the group consisting of: a binding agent disposed on or integrated with an outer surface of at least some of the surface-attached structures; a binding agent disposed on or integrated with the inside surface; and both of the foregoing, TONER, Column 15 line 12-36, Column 16 line 3-19.; Claim 96: wherein the method of claim 95, wherein isolating target comprises releasing the target after binding, such that the released target are flowable out from the flow cell; wherein releasing is selected from the group consisting of: flowing a release agent through the flow cell and into contact with the target bound to the binding agent disposed in the flow cell, TONER Column 17 line 40-43, Column 16 line 16-19; irradiating the bound target with photons under conditions configured for inducing photolysis; applying a shear force to the bound target at a magnitude configured for unbinding the bound targets; and a combination of two or more of the foregoing, TONER, Column 2 line 66-67, Column 16 line 3-19, Column 17, line 1-51.; Claim 97: wherein the method of claim 95, wherein isolating target comprises, releasing the target after binding, such that the released target are flowable out from the flow cell, TONER Column 16 line 3-19, Figure 8, 21, wherein releasing comprises flowing a release agent through the flow cell and into contact with the bound target, and the release agent is selected from the group consisting of: a chemical lysing agent; a pH cell lysing agent; an enzymatic liquefaction agent; and a solvent, TONER Column 16 line 3-19.; Claim 98: wherein the method of claim 95, wherein isolating the target comprises, releasing the target after binding, such that the released target are flowable out from the flow cell, TONER Column 16 line 3-19, Figure 8, 21, collection reservoir; wherein releasing comprises applying a shear force to the bound target at a magnitude configured for unbinding the bound targets, and applying the shear force, TONER Column 16 line 3-19, Figure 8, 21, is selected from the group consisting of: flowing a liquid through the flow cell at a flow rate configured for releasing the bound targets by shearing, TONER Column 16 line 3-19, Figure 8, 21, increased flow rate, that is higher shear force; applying a magnetic or electric field to the flow cell to actuate movement of the surface- attached structures at a speed configured for releasing the bound target by shearing; both of the foregoing.; Claim 99: wherein the method of claim 94, wherein a binding agent is disposed on or integrated with an outer surface of at least some of the surface-attached structures, and further comprising, while flowing the target-containing sample, applying a magnetic or electric field to the flow cell to actuate movement of the surface-attached structures in a reciprocating manner to increase a time- averaged cross-section of the surface-attached structures, TONER Column 14 line 10-44, EVANS Figure 4-6 Column 2 line 25-34, Column 4 line 34-53, actuation force may include magnetic, or electric force.; Claim 100: wherein the method of claim 94, wherein isolating target comprises trapping the target by preventing the target from passing between neighboring surface-attached structures; and after trapping, TONER Column 11 line 38-Column 12 line 48, Column 17 line 28-45, releasing the target by applying a magnetic or electric field to the flow cell to actuate movement of the surface-attached structures, EVANS Figure 4-6, page 1430-1432.; Claim 101: wherein the method of claim 94, wherein isolating the target comprises separating the target from non-targets of the target-containing sample by size or density, such that the target and the non-targets elute from the flow cell at different times, TONER Column 17 line 52-Column 18 line 15, sized based separation based on sieves that selectively allow passage of particles based on their size, shape or deformability; wherein: the target has a different size than the non-targets, TONER Column 17 line 52-Column 18 line 15; the inside surface is a top inside surface of the flow cell, TONER Figure 7 and 8, and the flow cell further comprises a bottom inside surface spaced from the top inside surface such that a structure-free region is between the surface- attached structures and the bottom inside surface, TONER Figure 8, Column 11 line 7-37; and the surface-attached structures are positioned with an inter- structure configured spacing effective for forcing either the target or the non-targets, whichever are larger, to flow substantially only through the structure-free region, TONER Figure 8, Column 11 line 7-37; or wherein: the target have a different density than the non-targets, TONER Column 17 line 52-Column 18 line 15; and the bottom inside surface is spaced from the top inside surface such that the structure-free region is between the surface- attached structures and the bottom inside surface and is below the surface- attached structures, TONER Figure 8, Column 11 line 7-37; and flowing the target-containing sample through the flow cell is done at a flow rate configured for allowing a majority of either the target or the non-targets, whichever are denser, to diffuse into the structure- free region and toward the bottom inside surface, TONER Column 15 line 12-37, Column 17 line 52-Column 18 line 15.; Claim 102: wherein the method of claim 94, comprising, while flowing the target-containing sample, applying a magnetic or electric field to the flow cell to actuate movement of the surface- attached structures, EVANS, Figure 3-6, page 1430-1432; comprising moving the surface- attached structures at a speed or frequency configured for causing an effect, EVANS page 1430, selected from the group consisting of: adjusting or varying an inter- structure spacing between the surface-attached structures, EVANS page 1429, rod array diameter an be from 200 nm to 1 micrometer; preventing or disrupting clogging of sample material between the surface- attached structures; preventing or disrupting non-specific binding of sample material on the surface- attached structures; and a combination of two or more of the foregoing, EVANS discloses the fabricated nanorod array are to act as biomimetic cilia. It is known in the art that biomimetic cilia are engineered structures designed to mimic the beating motion of natural cilia, which are used by many organisms to move fluids efficiently at microscopic scales.; Claim 103: wherein the method of any of claim 94, comprising, after isolating the target, transferring the target to an analytical instrument, and operating the analytical instrument to measure an attribute of the target, TONER Column 17 line 28-51.; Claim 107: wherein the method for extracting a target from a sample of claim 94, wherein the target is a non-analyte target comprising an interferent, suppressant, and/or element contributing only to background signal, and wherein the non-analyte target is isolated from the target-containing sample to purge the target-containing sample of the non-analyte target and/or to analyze the target-containing sample in the absence of the non-analyte target, TONER Column 10 line 55-65, surfaces contain specific substances that bind to certain subpopulation, Column 15 line 12-36, non-cellular matter, such as non-biological matter (e.g., beads), non-viable cellular debris (e.g., membrane fragments).; Claim 119: wherein the method of claim 94, wherein the surface-attached structures are oriented substantially along a direction normal to the inside surface of the flow cell at which are the surface- attached structures attached, or are oriented at an angle with respect to the direction normal to the inside surface of the flow cell at which are the surface-attached structures attached, EVANS Figure 1, 2, 5, page 1429 .; Claim 120: wherein the method of claim 94, wherein the surface- attached structures when actuated move in a movement pattern selected from the group consisting of: the surface-attached structures moving with a side-to-side two-dimensional motion; the surface-attached structures moving with a circular motion; the surface-attached structures moving in a tilted motion relative to the inside surface of the flow cell to which the surface-attached structures are attached; or a combination or two or more of the foregoing, EVANS Figure 4-6 , page 1430.; and Claim 121: wherein the method of claim 94, wherein a property of a fluid in an interior, a property of the surface-attached structures, or a property of binding agent in the interior of the flow cell is measured while flowing the target-containing sample through the flow cell, EVANS, Figure 4-6, page 1430-1431.; Claim 122: wherein the method of claim 94, wherein the magnetic or electric actuation force for actuating the one or more of the surface- attached structures is applied by a driver, EVANS, Figure 3, page 1430.; Claim 123: wherein the method of claim 94, wherein the binding or capturing comprises one or more of a physical, TONER Column 3 line 1-2, Column 5 line 34-37, size or shape or deformability, chemical, TONER Column 5 line 34-37, cell binding, or molecular interaction, TONER Column 5 line 34-37, cell binding, between the target and the at least one the surface-attached structures.; and Claim 124: wherein the method of claim 94, the actuation of the one or more surface- attached structures causes the targets of the target-containing sample to at least mix or circulate within the flow cell, EVANS discloses the fabricated nanorod array are to act as biomimetic cilia. It is known in the art that biomimetic cilia are engineered structures designed to mimic the beating motion of natural cilia, which are used by many organisms to move fluids efficiently at microscopic scales.; and Claim 125: wherein the method of claim 94, wherein the sample has a volume of greater than or equal to 10 mL, TONER Column 7 line 24-30, Column 10 line 5-10, line 32-36. ; Claim 126: wherein the flow cell is coupled to a fluidic circuit configured to establish a flow of fluid, TONER Figure 7, Column 11 line 7-18, pump, tubing, syringe etc. ; and Claim 127: wherein the method of claim 94, wherein the surface-attached structures are positioned in a fluid flow path between the fluid inlet and the fluid outlet such that the target-containing sample flowing through the flow cell comes into contact with the surface-attached structures, TONER Column 12 59 – Column 13 line 16. Applicant’s invention is drawn towards a method. Regarding Claim 104, the reference TONER discloses a method for extracting a target from a sample, abstract, separating cells from a sample, the method comprising: flowing a target-containing sample through a flow cell and into contact with surface- attached structures disposed in the flow cell, Figure 7, 8 and 17, Column 11 line 9-37, perfuse a mixture of cells through microfluidic device though inlet, Column 13 line 17-34, inlet for accepting blood / outlet for collection microfluidic device includes obstacles through flow chamber, wherein the surface- attached structures are attached to an inside surface of the flow cell at a plurality of respective attachment sites, Figure 8, Column 11 line 14-37, obstacles are in ordered array or randomly through flow chamber; and capturing the target on the surface-attached structures, Column 2 line 37-39, or on the inside surface of the flow cell, or on both the surface-attached structures and the inside surface, wherein applying the actuation increase the probability of an interaction between the target and at least one surface-attached structures, Column 2 line 66-Column 3 line 8, Column 16 line 14-19; and wherein capturing the target produces a depleted sample containing a reduced concentration of the target, and wherein the interaction comprises binding or capturing the target to the surface-attached structures, Claims 8, 9, 15, 16, selective binding, Column 2 line 38-39, 59-61, Column 3 line 38-51, Column 11 line 24-37, Column 15 line 22-26 and Column 16 line 3-6, capture of specific population of cells expressing certain surface model. The TONER reference discloses the claimed invention, but is silent in regards to application of a magnetic or electric field to the interior of the flow cell to actuate movement of one or more of the surface-attached structures relative to the attachment sites. The EVANS reference discloses a method, comprising: providing surface-attached structures disposed in a flow cell, Figure 1 and 2, pages 1429-1430, the flow cell is interpreted to be the space between the PDMS spacers, where fluid flow is to be investigated, page 1430, investigate fluid flow include by actuation of rod array, wherein the surface-attached are attached to an inside surface of the flow cell at a plurality of respective attachment sites, Figure 1 and 2, page 1429, nanorod array are attached to a glass slide / coverslip; and the surface – attached structures are movable in an interior of the flow cell relative to the attachment sites in response to applying a magnetic actuation, Figure 3-6, page 1429-1431. Thus, it would be obvious to one having ordinary skill in the art before the effective filing date to modify the TONER reference to include the nanorod arrays actuated by a magnetic field as taught by EVANS to study the mechanics of nanoscale fluid flow in a ciliated system, increase movement of the structure to increase contact with fluid in the flow cell to prevent sedimentation of fluids within the fluid cell as well as to prevent or disrupts clogging of sample material as it flow through the chamber. Additional Disclosures Included is : Claim 105: wherein the method of claim 104, comprising outputting the depleted sample from the flow cell, wherein the captured target remain captured in the flow cell, and releasing the captured target and outputting the released target from the flow cell, TONER Figure 21, outlet for depleted sample and collection reservoir for further analysis after release/removal, Column 10 line 56-65. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTINE T MUI whose telephone number is (571)270-3243. The examiner can normally be reached M-Th 5:30 -15:30 EST. 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, LYLE ALEXANDER can be reached at (571) 272-1254. 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. CTM /CHRISTINE T MUI/Primary Examiner, Art Unit 1797
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Prosecution Timeline

Show 6 earlier events
Oct 02, 2024
Request for Continued Examination
Oct 05, 2024
Response after Non-Final Action
Apr 17, 2025
Non-Final Rejection mailed — §103
Sep 17, 2025
Response Filed
Oct 29, 2025
Final Rejection mailed — §103
Apr 29, 2026
Request for Continued Examination
Apr 30, 2026
Response after Non-Final Action
May 12, 2026
Non-Final Rejection mailed — §103 (current)

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Prosecution Projections

5-6
Expected OA Rounds
78%
Grant Probability
98%
With Interview (+20.0%)
2y 8m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 1369 resolved cases by this examiner. Grant probability derived from career allowance rate.

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