Prosecution Insights
Last updated: July 17, 2026
Application No. 18/717,298

BIO-PEN STRUCTURE FOR IMPROVING MIXING HOMOGENEITY AND BIO-PRINTING METHOD USING THE SAME

Non-Final OA §103
Filed
Jun 06, 2024
Priority
Dec 06, 2021 — RE 10-2021-0172761 +4 more
Examiner
AHMED ALI, MOHAMED K
Art Unit
1743
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Foundation For Research And Business Seoul National University Of Science And Technology
OA Round
1 (Non-Final)
71%
Grant Probability
Favorable
1-2
OA Rounds
6m
Est. Remaining
97%
With Interview

Examiner Intelligence

Grants 71% — above average
71%
Career Allowance Rate
308 granted / 436 resolved
+5.6% vs TC avg
Strong +27% interview lift
Without
With
+26.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
31 currently pending
Career history
458
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
70.3%
+30.3% vs TC avg
§102
11.3%
-28.7% vs TC avg
§112
6.8%
-33.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 436 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 . Election/Restrictions Examiner contacted Applicant’s representative to correct a typo in the list of the claims for Group I in the restriction requirement mailed on 12/04/2025. The Examiner clarified that Group I includes claims 1-12 (not 1-13), the applicant’s representative confirmed the correction and elected (claims 1-12). Applicant’s election without traverse of Group I (claims 1-12) in the reply filed on 04/06/2026 is acknowledged. Claims 13-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Invention, there being no allowable generic or linking claim. Claim Rejections - 35 USC § 103 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. Claim(s) 1, 3-5, 8-9 and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over NOH (KR 102286073 with English Machine Translation - of record) in view of Peter (US 2,829,399 – of record). Regarding claim 1, Noh teaches an extrusion head (110) has a pen shape and capable of being a pen-type structure for mixing and discharging bio-ink or hydrogel (Figs. 1-2; [0003-0004] of English Machine Translation of record) and comprising: a cylindrical first barrel (111) configured to housing a first screw (210) and a second screw (220) (see Figs. 1-2; [0035] of English Machine Translation of record); a controller (driving unit (140)) connected to a gear (214) of the first screw and a gear of the second screw (220) in adjacent to the gear of the first screw and the gear of the second screw so as to drive the first screw and the second screw (see Figs. 2-4;[0051-0052] and [0055-0056] of English Machine Translation of record); two or more supply units (113,114) formed in the first barrel and supplying a bio-ink or hydrogel material into the first barrel (see Figs. 1-4; [0040-0041] and [0062-0068] of English Machine Translation - of record); and a bio-ink or hydrogel discharge unit (112) which extends from an end portion of the second barrel on an opposite side of the controller, and which discharges bio-ink or hydrogel (see Fig. 2; [0048] of English Machine Translation of record), wherein the first screw (210) and the second screw (220) are not spatially separated, the first screw has a variable pitch and a second screw has a variable pitch (see Fig. 2; [0014-0015], 0022] and [0048-0051] of English Machine Translation of record). However, Noh does not teach a cylindrical second barrel for housing the second screw which is longer than the first screw and has a structure parallel with the first screw, and formed to have a length longer than a length of the first barrel, wherein the first barrel and the second barrel are formed to extend in communication with each other so that the first screw and the second screw are not spatially separated, and wherein the variable pitch of the first screw has three sections and the variable pitch of the second screw has four sections. In the same field of endeavor, extrusion apparatuses, Peter teaches an extrusion device (1) (see Fig. 1), comprises a plurality of barrels (3a, 3b) configured to housing a first and a second screw (6a, 6b) respectively within the extrusion device (see Fig. 4; column 2, lines 48-51); the second screw is longer than the first screw and has a structure parallel with the first screw, and a second barrel formed to have a length longer than a length of the first barrel; a variable pitch of the first screw has three sections and a variable pitch of second screw has four sections (see column 5, line 73 and column 6, line 27). Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was filed to have modified the pen-type structure as taught by Noh In Sup in view of Peter with the second screw is longer than the first screw and has a structure parallel with the first screw, and a second barrel formed to have a length longer than a length of the first barrel; and the variable pitch of the first screw has three sections and the variable pitch of second screw has four section as such is known in the art of extrusion devices the discussion of Peter above; and doing so is combining prior art elements according to known methods to yield predictable results, with the added benefits of doing so would provide mixing efficiency and performance optimization in application like extrusion and mixing; and the variable pitch arrangement allow for controlled shear rates and better material conveyance. Regarding claim 3, Noh in view of Peter further teaches the pen-type structure, wherein the first screw and the second screw have a pitch phase difference of 45° to 135° (see [0015] and claim 3 of English Machine Translation of Noh of record). Regarding claim 4, Noh in view of Peter further teaches the pen-type structure, wherein a distance between a thread of the first screw and an inner wall of the first barrel ranges from 0.005 mm to 0.30 mm, and a distance between a thread of the second screw and an inner wall of the second barrel ranges from 0.005 mm to 0.30 mm (see [0038] of English Machine Translation of Noh of record). Regarding claim 5, Noh in view of Peter further teaches the pen-type structure, wherein a distance between a root of the first screw and an inner wall of the first barrel ranges from 0.01 mm to 6 mm, and a distance between a root of the second screw and an inner wall of the second barrel ranges from 0.01 mm to 6 mm (see [0038] of English Machine Translation of Noh of record). Regarding claim 8, Noh in view of Peter further teaches the pen-type structure, wherein the second screw is formed up to a point where a lower end portion of the second barrel and the bio-ink discharge unit come into contact with each other (see Figs. 1-4 of Noh and Fig. 4 of Peter). Regarding claim 9, Noh in view of Peter discloses the claimed invention except for an interval of the supply units does not exceed a length corresponding to 1/3 of a length of the second barrel. It would have been obvious to one of ordinary skill in the art at the time the invention was made to make an interval of the supply units does not exceed a length corresponding to 1/3 of a length of the second barrel. since such a modification would involve only a mere change in size of a component. Scaling up or down of an element which merely requires a change in size is generally considered as being within the ordinary skill in the art. One would have been motivated to scale the size of an interval of the supply units does not exceed a length corresponding to 1/3 of a length of the second barrel in order to control the flow of materials efficiently. (Please see MPEP 2144.04 IV A for further details). Regarding claim 12, Noh in view of Peter further teaches the pen-type structure (110), wherein the pen-type structure is mounted to be operable in a printing system (100) (bioprinting) (see Fig. 1; [0003-0004], [0008] and [0036] of English Machine Translation of Noh of record). Claim(s) 2 is/are rejected under 35 U.S.C. 103 as being unpatentable over NOH (KR 102286073 with English Machine Translation – of record) in view of Peter (US 2,829,399 – of record) as applied to claim 1 above, and further in view of Carlo (US 2,676,355). Regarding claim 2, Noh in view of Peter teaches the pen-type structure as discussed in claim 1 above. Peter further teaches wherein the first screw has a section a, a section b, a section c and a section d sequentially in a direction from the controller to the bio-ink or hydrogel discharge unit (see Figs. 1-2; column 2, lines 11-15). However, Noh in view of Peter does not teach a pitch size of each section is b < a ≤c, the second screw has a section d, a section e, a section f, and a section g sequentially in a direction from the controller to the bio-ink or hydrogel discharge unit, a pitch size of each section is e < d ≤ f, and a pitch size of the section g satisfies following conditions i) and ii): i) g < f ii) e ≤ g or e > g. In the same field of endeavor, screws for extrusion devices, Carlo teaches a screw press for extruding plastic materials (Abstract; Fig. 1), comprises intermeshing screws (2,3) subdivided into multiple sections (2a, 2b, 2c and 3a, 3b, 3c) with different pitch sizes (gradual or stepped) (see Fig. 2; column 2, lines 47-55). Carlo further discloses a variable pitch configuration that can be adapted to achieve the specific pitch relationship for optimizing (see column 1, lines 10-16, lines 54-55 and column 2, lines 1-5). Carlo discloses varying the pitch from the inlet to the extrusion die, in employing screws with a decreasing thread diameter and an increasing core diameter, the increase and decrease, respectively, being gradual or by steps and varying the pitch in order to reduce friction between the screw and casing and to improve flow of the plastic materials (see column 1, lines 54-55 and column 2, lines 1-5). It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the invention to have a pitch size of each section is b < a ≤c, the second screw has a section d, a section e, a section f, and a section g sequentially in a direction from the controller to the bio-ink or hydrogel discharge unit, a pitch size of each section is e < d ≤ f, and a pitch size of the section g satisfies following conditions i) and ii): i) g < f and ii) e ≤ g or e > g, as such is known in the art of extrusion devices given the discussion of Carlo above presenting a reasonably expectation of success; and doing would involve only a mere change in size of a component. Scaling up or down of an element which merely requires a change in size is generally considered as being within the ordinary skill in the art. One would have been motivated to scale a pitch size of each section is b < a ≤c, the second screw has a section d, a section e, a section f, and a section g sequentially in a direction from the controller to the bio-ink or hydrogel discharge unit, a pitch size of each section is e < d ≤ f, and a pitch size of the section g satisfies following conditions i) and ii): i) g < f and ii) e ≤ g or e > g in order to reduce friction between the screw and casing and to improve flow of the plastic materials (see column 1, lines 54-55 and column 2, lines 1-5 of Carlo). Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over NOH (KR 102286073 with English Machine Translation – of record) in view of Peter (US 2,829,399 – of record) as applied to claim 1 above, and further in view of Lu (US 5,873,654). Regarding claim 6, Noh in view of Peter teaches the pen-type structure as discussed in claim 1 above. Noh in view of Peter does not teach wherein a distance between a shaft center of the first screw and a shaft center of the second screw is formed to be longer than a shaft diameter of the first screw or the second screw. In the same field of endeavor, extrusion apparatuses, Lu teaches a twin screw extruder type comprises a barrel housing (11) consist of different sections configured for housing two screws (16,17) parallel to each other with a distance between the two screw center lines being larger or equal than the half of the sum of two screw diameters and (see Figs. 2a-2b; column 2, lines 25-30, lines 38-40 and lines 50-54). Lu further discloses teaches that a configuration of two screws parallel to each other with the distance between the two screw center lines being larger or equal than the half of the sum of two screw diameters to provide a design of a batch mixer which has an efficient material discharge mechanism and the material can be formed into certain shape per discharge (Abstract; column 2, lines 1-5). It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the invention to have a distance between a shaft center of the first screw and a shaft center of the second screw is formed to be longer than a shaft diameter of the first screw or the second screw as such is known in the art of extrusion devices given the discussion of Lu above presenting a reasonably expectation of success; and doing would involve only a mere change in size of a component. Scaling up or down of an element which merely requires a change in size is generally considered as being within the ordinary skill in the art. One would have been motivated to scale the distance between a shaft center of the first screw and a shaft center of the second screw is formed to be longer than a shaft diameter of the first screw or the second screw in order to prevent mechanical interference between the screws, reducing shear stress on sensitive material like bio-ink or hydrogel and improve mixing efficiency. Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over NOH (KR 102286073 with English Machine Translation – of record) in view of Peter (US 2,829,399 – of record) as applied to claim 1 above, and further in view of Rauwendaal (US 5,932,159). Regarding claim 7, Noh in view of Peter teaches the pen-type structure as discussed in claim 1 above. Noh further a lower end portion of the first barrel has an inner wall in a direction parallel to an axis of the first screw (210), and a distance between the inner wall and an end point of the first screw (see Figs. 2-4 ). However, Noh in view of Peter does not teach a distance between the inner wall and an end point of the first screw ranges from 0.005 mm to 1 mm. In the same field of endeavor, screws for extrusion devices, Rauwendaal teaches a screw extruder (10), comprises a barrel (18) having a bore (26) which defines barrel’s inner surface (24) (Abstract; Fig. 1), and a screw (28) has a flight clearance (δ) defined as the distance between the flight tip and the inner surface (i.e. a distance between the inner wall and the screw endpoint); a clearance ratio (δ/D) defined as 0.005 to 0.250, where D is the screw diameter (see column 5, lines 53-52; column 7, lines 18-25). For a typical screw diameter (e.g., D =10 mm), based on the ratio of δ/D as disclosed by Rauwendaal, the clearance ranges translates to δ= 0.005 x10mm = 0.05 mm (for the lower bound) and bound δ=0.250 x10mm = 2.5 mm (the upper bound). It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the invention to have a distance between the inner wall and an end point of the first screw ranges from 0.005 mm to 1 mm as such is known in the art of extrusion devices given the discussion of Rauwendaal above presenting a reasonably expectation of success; and doing would involve only a mere change in size of a component. Scaling up or down of an element which merely requires a change in size is generally considered as being within the ordinary skill in the art. One would have been motivated to scale the distance between a shaft center of the first screw and a shaft center of the second screw is formed to be longer than a shaft diameter of the first screw or the second screw in order provide screw extruder having pushing face profiles that form progressively narrowing passages in conjunction with barrel inner surfaces to provide improved dispersive mixing (see column 5, lines 53-56 of Rauwendaal). Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over NOH (KR 102286073 with English Machine Translation – of record) in view of Peter (US 2,829,399 – of record) as applied to claim 1 above, and further in view of Cambron (US 2020/0398494). Regarding claim 10, Noh in view of Peter teaches the pen-type structure as discussed in claim 1 above. Noh in view of Peter does not teach wherein the bio-ink discharge unit is capable of attaching and detaching an extrusion head selected from a roller, a brush, or a needle. In the same field of endeavor, extrusion devices, Cambron teaches a three-dimensional printer (10) configured for extruding material in layers (see Fig. 1A; [0003]), comprises a material discharge unit (a material barrel (30)) containing materials to be extruded, wherein the material barrel (30) is capable of attaching and detaching an extrusion head (100) selected from a roller, a brush, or a needle (38) (see Fig. 1B; [0019-0020]). It would have been obvious to one having ordinary skill in the art at the time the invention was filed to have modified the pen-type structure as taught by Noh in view Cambron with configuring the bio-ink discharge to be capable of attaching and detaching an extrusion head selected from a roller, a brush, or a needle as such is known in the art of extrusion devices given the discussion of Cambron above; and doing so is combining prior art elements according to known methods to yield predictable results, with the added benefits of doing so would provide a controlled material flow and avoid waist of materials. Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over NOH (KR 102286073 with English Machine Translation – of record) in view of Peter (US 2,829,399 – of record) as applied to claim 1 above, and further in view of Marple (EP 1484148). Regarding claim 11, Noh in view of Peter teaches the pen-type structure as discussed in claim 1 above. Noh in view of Peter does not teach wherein the first barrel and/or the second barrel have one or more ultraviolet or laser light sources so that light is irradiated to the bio-ink or hydrogel to be discharged. In analogous art, devices for extruding materials, Marple teaches an extruder (98) forming an extruded product using a UV curable liquid (see Fig. 5; [0026]), the extruder comprises a barrel (die (90)) of a desired configuration with a UV transmissible wall (92), wherein the die configured to receive UV curable material; and the UV transmissible wall (92) is illuminated with UV light source (95) of sufficient intensity and for a sufficient period to cure the UV curable material (see Fig. 5; [0026]) It would have been obvious to one having ordinary skill in the art at the time the invention was filed to have modified the pen-type structure as taught by Noh in view Marple with configuring the first barrel and/or the second barrel have one or more ultraviolet or laser light sources so that light is irradiated to the bio-ink or hydrogel to be discharged as such is known in the art of extrusion devices given the discussion of Marple above; and doing so is combining prior art elements according to known methods to yield predictable results, with the added benefits of doing so would eliminate the need for separate curing steps, improving efficiency and ensuring uniform curing. Conclusion The following prior arts made of record and not relied upon is considered pertinent to applicant's disclosure: Hauser (US 2022/0055297) teaches a nozzle for 3D tissue using bio-ink (Abstract; [0022] and [0035]), comprises a cylindrical first barrel (122) configured to housing a first screw (312) and a cylindrical second barrel (128) for housing a second screw (314) which is longer than the first screw (see Figs. 1-3;[0035] and [0045-0048]). Ozbolat (US 2016/0288414) teaches a bioprinter printer head (30) can have a nozzle assembly (50) comprises configured to receive and dispense the at least one biomaterial as the arm assembly (32) (see Fig. 6;[0107-0109]). Any inquiry concerning this communication or earlier communications from the examiner should be directed to MOHAMED K AHMED ALI whose telephone number is (571)272-0347. The examiner can normally be reached 10:00 AM-7:30 PM. 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, Galen Hauth can be reached at 571-270-5516. 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. /MOHAMED K AHMED ALI/Examiner, Art Unit 1743 /GALEN H HAUTH/Supervisory Patent Examiner, Art Unit 1743
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Prosecution Timeline

Jun 06, 2024
Application Filed
May 27, 2026
Non-Final Rejection mailed — §103 (current)

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Prosecution Projections

1-2
Expected OA Rounds
71%
Grant Probability
97%
With Interview (+26.7%)
2y 8m (~6m remaining)
Median Time to Grant
Low
PTA Risk
Based on 436 resolved cases by this examiner. Grant probability derived from career allowance rate.

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