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 .
Drawings
Figs. 2, 4-6 appear blurry and are not clearly legible. The drawings are not of sufficient quality to permit examination. Accordingly, replacement drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to this Office action. The replacement sheet(s) should be labeled “Replacement Sheet” in the page header (as per 37 CFR 1.84(c)) so as not to obstruct any portion of the drawing figures. If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action.
Applicant is given a shortened statutory period of TWO (2) MONTHS to submit new drawings in compliance with 37 CFR 1.81. Extensions of time may be obtained under the provisions of 37 CFR 1.136(a) but in no case can any extension carry the date for reply to this letter beyond the maximum period of SIX MONTHS set by statute (35 U.S.C. 133). Failure to timely submit replacement drawing sheets will result in ABANDONMENT of the application.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1, 10, 19 are rejected under AIA 35 U.S.C. 102(a)(1) as being anticipated by Hiddessen et. al (US 20170056884 A1).
Regarding claim 1, Hiddessen teaches a method of concentrating droplets in an emulsion (methods…for forming and concentrating emulsions; Abstract) comprising:
a) providing a device (emulsion formation unit 200; [0086]; See Fig. 11 below) comprising:
i) a first channel (sample inlet channel 214; [0087; Fig. 11) having a first proximal end (See where the inlet channel 214 meets the sample reservoir 170), a first distal end (see where outlet channel 216 meets the collection container 172; [0087]; Fig. 11), a first depth, and a first width (Channels 210-216 may have different cross-sectional sizes (i.e., diameters/widths and/or depths); [0087]);
ii) a droplet source region (droplet generator 198; [0085]; Fig. 11) in fluid communication with the first distal end of the first channel (See Fig. 11 below)
wherein the droplet source region has a width or depth greater than the first width or first depth (“a wider/deeper region 222 downstream of region 220 for droplet formation and stabilization,” wherein “Region 222 may begin upstream of droplet generator 198 for each of the inlet channels and may extend from the droplet generator via outlet channel 216”; [0088]; Fig. 11) and
iii) a collection reservoir (collection container…172; [0085]; Fig. 11) in fluid communication with the droplet source region that collects droplets formed in the droplet source region (The reservoirs and the collection container may be fluidically interconnected via channels 210-216 that intersect at droplet generator 198);
b) flowing a first liquid (sample 208; [0085]; Figs. 9, 11) from the first proximal end to the droplet source region to produce an emulsion of droplets of the first liquid in a second liquid (oil phase 206; [0085]; Figs. 9, 11) in the collection reservoir (Collection container 192 (i.e., well 172) may receive and collect an emulsion 209 formed by droplet generator 198 from oil phase 206 and sample 208; [0085]; Figs. 9, 11); and
c) reducing the volume of the second liquid in the emulsion by applying a first pressure differential for a first period of time and a second pressure differential for a second period of time to produce a concentrated emulsion (The system also may comprise an instrument configured to operatively receive the device and to create (i) a first pressure differential to produce an emulsion collected in the droplet well and (ii) a second pressure differential to decrease a volume fraction of continuous-phase fluid in the emulsion; Abstract; See Fig. 17).
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Fig. 11 of Hiddessen
Regarding claim 10, Hiddessen teaches the method of claim 1, wherein the device further comprises a first reservoir (Inlet reservoirs…well…170; [0085]; Fig. 11) in fluid communication with the first proximal end (See Figs. 9, 11 where 214 meets 170), and the first and second pressure differentials transport the second liquid from the collection reservoir to the first reservoir (“The positive pressure may drive continuous phase 206…from emulsion 348, in reverse along the flow path between each output well 172 and input wells 168, 170. As a result, removed volumes 374, 376 of phase 206 may be collected in wells 168 and/or 170, and emulsion 348 may become more concentrated,” wherein “The pressure that concentrates the emulsion may be…in one or more timed steps,” which would constitute first and second pressure differentials; [0125]; Figs. 9,11,17).
Regarding claim 19, Hiddessen teaches the method of claim 1, wherein the second liquid is an oil (oil phase 206; [0085]; Figs. 9, 11)
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.
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 2-3 are rejected under 35 U.S.C. 103 as being unpatentable over Hiddessen et. al (US 20170056884 A1) in view of Baudry et al. (US 20110188717 A1).
Regarding claim 2, Hiddessen teaches the method of claim 1.
Hiddessen fails to teach removing the concentrated emulsion in about equal aliquots by pipetting.
Baudry teaches removing the concentrated emulsion by pipetting (“a pipette 18 is used for collecting droplets,” wherein ”an emulsion (3) [includes] droplets and a continuous phase surrounding the droplets; [0186]; Abstract).
Baudry is considered to be analogous to the claimed invention because it is in the same field of endeavor for assessing the volume fraction of droplets in an emulsion. The aim of Hiddessen is to create a monodispersed emulsion of droplets that contains a sample within an immiscible oil phase. Hiddessen achieves this by draining the excess oil from the emulsion and thereby packing the droplets closer together. Baudry teaches a method for testing the volume fraction of droplets within an emulsion that includes oil. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method for concentrating droplets taught by Hiddessen by incorporating the teachings of Baudry and removing aliquots of the final emulsion for testing for the viability of the method. Doing so would yield the predictable result of revealing which steps in the method would require more optimization to achieve the desired monodispersity and volume fractions, a technique which is well-known in the art (See MPEP 2143(I)(A)).
Modified Hiddessen is silent to teaching the aliquots are equal. However, repeatable experimentation is well-known in the art as a way to produce accurate and precise results. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized a selected volume within the pipette limits for sample aspiration so as to ensure consistent downstream processing and analysis (See MPE 2144.05).
Regarding claim 3, Modified Hiddessen teaches the method of claim 2, wherein the volume fraction of the second liquid in the aliquots is about the same (a pipette 18 is used for collecting droplets 21 from chamber 25 at the level of a layer which has, locally, a desired volume fraction of droplets .PHI. (i.e. a concentration of droplets) greater than or equal to 40%; [0186]).
Claims 4-9 are rejected under 35 U.S.C. 103 as being unpatentable over Hiddessen et. al (US 20170056884 A1) in view of Wang (US 20190154715 A1).
Regarding claim 4, Hiddessen teaches the method of claim 1,
Hiddessen fails to teach the second period of time is greater than the first period of time.
Wang illustrates how various pressure differentials over time affect the droplet volume within a microfluidic device (Fig. 5b shows that droplets become larger at greater pressures in a shorter amount of time). Wang starts by producing larger droplets (plugs) which are then separated into smaller daughter droplets resulting in an increase in monodispersity ([0077]);
Wang is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen already teaches that an algorithm determines the length of time that a pressure is applied which is proportional to the duration of emulsion formation ([0125]). Additionally, paragraphs [0165]-[0166] explain that the second length of time is based on (or proportional to) the first length of time. The duration of time by which the pressure differential is applied is therefore a result-effective variable, and it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the time duration as taught by Wang (which includes the claimed timing order) in order to achieve the desired level of emulsification and monodispersity (See MPEP 2144.05).
Regarding claim 5, Hiddessen teaches the method of claim 1.
Hiddessen fails to teach the first pressure differential is greater than the second pressure differential.
Wang illustrates how various pressure differentials over time affect the droplet volume within a microfluidic device (Fig. 5b shows that droplets become larger at greater pressures in a shorter amount of time). Wang starts by producing larger droplets (plugs) which are then separated into smaller daughter droplets resulting in an increase in monodispersity ([0077]);
Wang is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen already teaches that the pressure differentials are determined based on a number of different variables such as the detected pressures in the reservoirs, flow resistance within the channels, and the pressure needed to maintain a degree of monodispersity of the formed emulsion for a more uniform emulsion droplet size ([0108]-[0109]). The magnitude of the first and second pressure differential is therefore a result-effective variable, and it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the pressure differentials as taught by Wang (including a first pressure differential greater than the second as claimed) in order to achieve the desired degree of stabilized emulsion concentration and monodispersity (See MPEP 2144.05).
Regarding claim 6, Hiddessen teaches the method of claim 1.
Hiddessen fails to teach the first period of time is between 1 sec and 60 sec.
Wang illustrates how various pressure differentials over time affect the droplet volume within a microfluidic device (Fig. 5b shows that droplets become larger at greater pressures in a shorter amount of time). Wang starts by producing larger droplets (plugs) which are then separated into smaller daughter droplets resulting in an increase in monodispersity ([0077]).
Wang is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen already teaches controlling emulsion formation and concentration using multiple adjustable parameters, including pressure magnitude, pressure duration, stopping criteria, and timing of subsequent pressure application ([0120]-[0125]). The reference discloses stopping pressures are based on droplet formation percentage or system conditions, maintaining pressure within predefined ranges, allowing droplets to pack over time period (including between 1 and 60 secs), and applying a second pressure (constant or ramped) for a selectable duration to increase droplet concentration. These parameters are result-effective variables that affect droplet formation, monodispersity, and concentration, and it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the time duration as taught by Wang (which includes the claimed time duration) in order to achieve the desired level of emulsification and monodispersity (See MPEP 2144.05).
Regarding claim 7, Hiddessen teaches the method of claim 1,
Hiddessen fails to teach the second period of time is between 30 sec and 600 sec.
Wang illustrates how various pressure differentials over time affect the droplet volume within a microfluidic device (Fig. 5b shows that droplets become larger at greater pressures in a shorter amount of time). Wang starts by producing larger droplets (plugs) which are then separated into smaller daughter droplets resulting in an increase in monodispersity ([0077]).
Wang is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen already teaches controlling emulsion formation and concentration using multiple adjustable parameters, including pressure magnitude, pressure duration, stopping criteria, and timing of subsequent pressure application ([0120]-[0125]). The reference discloses stopping pressures are based on droplet formation percentage or system conditions, maintaining pressure within predefined ranges, allowing droplets to pack over time period (including between 1 and 60 secs), and applying a second pressure (constant or ramped) for a selectable duration to increase droplet concentration. These parameters are result-effective variables that affect droplet formation, monodispersity, and concentration, and it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the time duration as taught by Wang (which includes the claimed time duration) in order to achieve the desired level of emulsification and monodispersity (See MPEP 2144.05).
Regarding claim 8, Hiddessen teaches the method of claim 1, wherein the first pressure differential is in a range that overlaps between 1.0 PSI and 10 PSI (“Positive pressure controller 88 may establish a positive pressure…according to a set point, such as a positive pressure of less than about 10 psi (˜69 kPa) (e.g., about 0.5 to 10 psi,” wherein “positive pressure applied to wells 168, 170 may drive emulsion formation”; [0110];[0114]); Fig. 17).
Wang illustrates how various pressure differentials over time affect the droplet volume within a microfluidic device (Fig. 5b shows that droplets become larger at greater pressures in a shorter amount of time). Wang starts by producing larger droplets (plugs) which are then separated into smaller daughter droplets resulting in an increase in monodispersity ([0077]).
Wang is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen teaches that the pressure differentials are determined based on a number of different variables such as the detected pressures in the reservoirs, flow resistance within the channels, and the pressure needed to maintain a degree of monodispersity of the formed emulsion for a more uniform emulsion droplet size ([0108]-[0109]). The magnitudes of the first and second pressure differentials are therefore a result-effective variable, and it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized them to be within the claimed range in order to achieve the desired degree of stabilized emulsion concentration (See MPEP 2144.05).
Regarding claim 9, Hiddessen teaches the method of claim 1, wherein a second pressure differential is in a range that overlaps between 0.01 PSI and 1.0 PSI (Negative pressure controller 86 may establish a negative pressure in conduit 316 (i.e., a second reservoir) according to a set point, such as a negative pressure (e.g., about −0.5 to −4.5 psi; [0108]).
Wang illustrates how various pressure differentials over time affect the droplet volume within a microfluidic device (Fig. 5b shows that droplets become larger at greater pressures in a shorter amount of time). Wang starts by producing larger droplets (plugs) which are then separated into smaller daughter droplets resulting in an increase in monodispersity ([0077]).
Wang is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen teaches that the pressure differentials are determined based on a number of different variables such as the detected pressures in the reservoirs, flow resistance within the channels, and the pressure needed to maintain a degree of monodispersity of the formed emulsion for a more uniform emulsion droplet size ([0108]-[0109]). The magnitudes of the first and second pressure differentials are therefore a result-effective variable, and it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized them to be within the claimed range in order to achieve the desired degree of stabilized emulsion concentration (See MPEP 2144.05).
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Hiddessen et. al (US 20170056884 A1).
Regarding claim 21, Hiddessen teaches the method of claim 1.
Hiddessen is silent to teaching the concentrated emulsion comprises at least 80% droplets by volume. However, Hiddessen does teach that “application of the pressure is stopped when at least about 80% by volume of each of the samples has been converted to droplets” ([0151]). Conversion percent reflects the extent to which the original sample volume has been partitioned into droplets, which is controlled by variables such as pressure and duration of application. Although this parameter is distinct from the volume fraction of droplets within the overall emulsion, the volume fraction is nevertheless a result-effect variable governing droplet generation efficiency. Fig. 17 shows the progression of an increasing volume fraction of droplets (348) in the second liquid (oil, 206) in which paragraph [0125] states is dependent upon the length of time that pressure is applied. Additionally, paragraph [0109] states that a tighter control of a predefined pressure can create a more uniform emulsion droplet size (monodispersity) which is beneficial for more reproducible results in downstream analysis. Accordingly, it would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the result-effective variables of pressure and time to create an emulsion comprising at least 80% droplets by volume in order to achieve a desired level of monodispersity and sample conversion (See MPEP 2144.05).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Hiddessen et. al (US 20170056884 A1) in view of Colston (US 20100173394 A1).
Regarding claim 11, Hiddessen teaches the method of claim 1.
Hiddessen fails to teach the first liquid comprises particles, and the droplets further comprise the particles.
Colston teaches that a liquid used to create a droplet comprises particles, and the droplets further comprise the particles (Paragraph [0145] states that particles and the sample may be present in any of the emulsion phases).
Colston is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen already teaches that “a fluorophore is present in and/or is added to at least one of the prospective emulsion phases” in order to detect optical characteristics ([0118]). Colston adds fluorophores to the emulsion through the use of “fluorescent particles such as quantum dots, polymer beads, etc.” ([1054]). It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have substituted Hiddessen’s generic fluorophore for Colston’s fluorescent particles since there are only a finite number of identified, predictable forms by which a fluorophore can be added to a sample. Fluorescent particles are well-known in the art for use in emulsions and since both Hiddessen and Colston teach an emulsion comprising an oil and aqueous phase, adding fluorescent particles would yield the predictable result of revealing the optical characteristics of the droplet (See MPEP 2143(I)(B and E)).
Claims 12-16 are rejected under 35 U.S.C. 103 as being unpatentable over Hiddessen et. al (US 20170056884 A1) in view of Wheeler et al. (WO 2019083852 A1, see attached English translation).
Regarding claim 12, Hiddessen teaches the method of claim 1, wherein the device further comprises a second channel (oil inlet channels 210; [0085]; Fig. 11) having a second proximal end (See Fig. 11 above), a second distal end, a second depth, a second width (Channels 210-216 may have different cross-sectional sizes (i.e., diameters/widths and/or depths); [0087]);
wherein the second channel intersects the first channel between the first proximal end and the first distal end (See intersection of the 222 region that connects channels 210 and 214 in Fig. 11), and
Hiddessen fails to teach wherein step (b) further comprises flowing a third liquid from the second proximal end to the intersection where it combines with the first liquid, and the droplets further comprise the third liquid.
Wheeler teaches flowing a third liquid from a second proximal end to an intersection where it combines with a first liquid, and droplets comprise the first and third liquid (Paragraph [00228] and Fig. 10 explain that a third liquid can flow from well 1001b and combine with a second liquid from 1001a. These two liquids combine at the second proximal end and then flow down to the droplet generating junction 1010. This junction accommodates the mixture of the second, third and a first liquid that would flow from the other connecting channels. Intersection 222 (Figs. 9,11) of Hiddessen would still serve as the configuration of the intersection between the first and third fluid which would then generate droplets at 198)(See Fig. 10 of Wheeler below).
Wheeler is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Wheeler teaches that “it may be beneficial to merge one or more wells and/or channel segments when larger input volumes are required”. Wheeler also states that doing so helps to “stabilize the fluid flow dynamics…facilitate uniformity of droplet size [and] facilitate monodispersity of occupied droplets” ([00205]). It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the microfluidic system taught by Hiddessen by incorporating the teachings of Wheeler to include a third liquid that combines with the first liquid to create the droplets. Introducing more volume of fluid is well-known in the art and doing so would yield the predictable results stated by Wheeler above (See MPEP 2143(I)(A)).
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Fig. 10 of Wheeler (WO 2019083852 A1), see attached English translation)
Regarding claim 13, Hiddessen teaches the method of claim 12, wherein the device further comprises a second reservoir (Inlet reservoirs…well…168; [0085]; See Fig. 11 above) in fluid communication with the second proximal end (See where the oil channel 210 meets the sample reservoir 168 in Fig. 11) and wherein during step (c) the pressures in the second reservoir and in the collection reservoir are substantially the same (Hiddessen teaches “negative pressure may be applied to output wells 172 and positive pressure may be applied at the same time to at least a subset of the input wells (such as each of wells 168 or each of wells 170),” and also that maintaining a very precise predefined applied pressure at the point of emulsion is important for higher monodispersity (more uniform emulsion droplet size); [0102];[0109]).
Regarding claim 14, Hiddessen teaches the method of claim 1.
Hiddessen fails to teach the device further comprises a third channel having a third proximal end and a third distal end, wherein the third proximal end is in fluid communication with the collection reservoir, and the first and second pressure differentials transport the second liquid from the collection reservoir to the third distal end.
Wheeler teaches a third channel (shunt 906; [00214]; Fig. 9 or labeled Fig. 10 above) having a third proximal end (See where shunt 906 meets emulsion well 902 in Fig. 9) and a third distal end (See where shunt 906 meets drainage well 904 in Fig. 9), wherein the third proximal end is in fluid communication with the collection reservoir (The emulsion well 902 may be in fluid communication with the drainage well 904 via the shunt 906,” wherein emulsion well 902 is the collection reservoir; [00214]; Fig. 9), and pressure differential transports the second liquid from the collection reservoir to the third distal end (A hydrostatic pressure differential between the liquid levels in the two wells 902, 904 may subject the excess partitioning fluid to drain from the emulsion well 902 to the drainage well 904; [00214]; Fig. 9).
Wheeler is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen teaches concentrating droplets in an emulsion by reducing the volume of the second liquid but does so by reversing the flow from the collection unit back into the inlet channels and then to the corresponding inlet reservoir ([0125]). Wheeler teaches an entirely separate channel that extends from the collection reservoir into its own drainage well and also teaches that the second liquid can be recycled from the drainage well back to one of the inlet wells. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the microfluidic system taught by Hiddessen by incorporating a third channel from the collection reservoir in order to create a continuous flow without disturbing the droplets. Doing so would yield the predictable results of a more reliable operation and a quicker process while still preserving Hiddenssen’s intent of recycling the second fluid (See MPEP 2143(I)(A and C)).
Regarding claim 15, Hiddessen teaches the method of claim 14.
Modified Hiddessen fails to teach a third reservoir in fluid communication with the third distal end.
Wheeler teaches a third reservoir (drainage well 904; [00214]; Fig. 9) in fluid communication with the third distal end (excess partitioning fluid (e.g., excess oil) may be directed from the emulsion well 902 to the drainage well 904 through the shunt 906; [00214]; Fig. 9).
Wheeler is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Hiddessen teaches concentrating droplets in an emulsion by reducing the volume of the second liquid but does so by reversing the flow from the collection unit back into the inlet channels and then to the corresponding inlet reservoir ([0125]). Wheeler teaches an entirely separate channel that extends from the collection reservoir into its own drainage well and also teaches that the second liquid can be recycled from the drainage well back to the original inlet well that contained the second or first fluid. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the microfluidic system taught by Hiddessen in view of Wheeler by further incorporating the teachings of Wheeler to include a third channel from the collection reservoir in order to. Doing so would yield the predictable results of a more reliable operation and a quicker process while still preserving Hiddenssen’s intent of recycling the second fluid (See MPEP 2143(I)(A and C)).
Regarding claim 16, Hiddessen teaches the method of claim 14.
Modified Hiddessen fails to teach the interface between the collection reservoir and the third proximal end has a depth between 10 pm and 50 pm.
However, Modified Hiddessen teaches draining excess partitioning fluid (second fluid) from an emulsion well (collection reservoir) to a drainage well (third reservoir) via a shunt (third channel) under a hydrostatic pressure differential (Wheeler, [00214]). Modified Hiddessen further teaches that the dimensions (depth of 100 µm or less) and resistance of the shunt may be varied to control both the rate of drainage and back-flow from the drainage well to the emulsion well (Wheeler, [00215]-[00218]). Fluidic resistance is dependent on channel dimensions, including depth, and increased resistance reduces both drainage rate and back-flow. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized the interface depth to be within the claimed range of 10-50 µm to achieve controlled drainage while preventing undesirable back-flow and preserving the integrity of the emulsion (See MPEP 2144.05 and 2143(I)(C)).
Claims 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Hiddessen et. al (US 20170056884 A1) in view of Wheeler et al. (WO 2019083852 A1, see attached English translation), as applied to claim 14 above, and in further view of Khalilabad et al. (US 20180071739 A1).
Regarding claim 17, Hiddessen teaches the method of claim 14.
Modified Hiddessen fails to teach the device further comprises a filter to impede droplets from entering the third channel.
Khalilabad teaches a filter to impede droplets from entering a channel (The posts 556 allow the oil to be extracted via an outlet while containing the droplets 554; [0068]; Fig. 5).
Khalilabad is considered to be analogous to the claimed invention because it is in the same field of endeavor of using microfluidics devices for forming and partitioning droplet emulsions. Modified Hiddessen already teaches draining excess fluid from the collection reservoir through an outlet channel in order to concentrate the droplets. Likewise, Khalilabad teaches removing excess oil in the emulsion by via an outlet. It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the microfluidic system taught by Hiddessen in view of Wheeler by incorporating the filter taught by Khalilabad in order to independently extract the second liquid while preventing the loss of droplets during removal. Doing so would yield the predictable result of an improved separation of phases and create a more pure second fluid recycling stream to be used in future droplet formations (Wheeler, [00214])(See MPEP 2143(I)(A)).
Regarding claim 18, Hiddessen teaches the method of claim 17, wherein the filter comprises a plurality of pillars (The posts 556 allow the oil to be extracted via an outlet while containing the droplets 554; [0068]; Khalilabad; Fig. 5).
Conclusion
No claims are allowed.
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/V.S./Examiner, Art Unit 1758
/MARIS R KESSEL/Supervisory Patent Examiner, Art Unit 1758