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
Applicant's election with traverse of Invention I in the reply filed on 2/13/2026 is acknowledged. The traversal is on the ground(s) that Invention I is basically the same as that on Invention II and Invention III, and any prior art searched for one group is applicable to the other group. This is not found persuasive because Invention II and Invention III are related to cell-laden droplets, where a search of cell-laden droplets would not necessarily appear in a search for the particle-laden droplets of Invention I. Further, Inventions II and III contain dependent claims and limitations that would not appear in a search for Invention I, and would require different combinations of references to reach the instant inventions. Therefore, the requirement is still deemed proper and is made FINAL.
Claim Objections
Claim 1 is objected to because of the following informalities: In line 7, the term “a droplet generator (120)” should be changed to “the droplet generator (120)” since line 2 provides antecedent basis. Appropriate correction is required.
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 1, and 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Xu et al. (US 2021/0308678), and further in view of Lutz et al. (US 2005/0194314), Qiao et al. (“Droplet behavior in a Taylor vortex”).
Regarding claim 1, Xu et al. teaches A method (method of detecting molecules using droplet microfluidics, see Abstract) comprising:
a. providing a microfluidic system (Fig. 2-3) comprising a droplet generator and a microfluidic platform (droplet generator connected to microfluidic channel and storage chamber, see Fig. 2-3 and [0026]) comprising an inlet (channel from droplet actuator, see Fig. 2-3), a fluidic chamber fluidly coupled to the inlet (storage chamber), and an outlet fluidly coupled to the fluidic chamber (outlet opposite to storage chamber), wherein the fluidic chamber comprises one or more trapping arrays (the storage chamber contains anchoring structure for trapping droplets, see Fig. 5, [0026], and [0096]);
b. accepting, by a droplet generator (120), one or more particles (droplet generator accepts sample by inlet, see Fig. 2-3 and [0063]);
c. generating, by the droplet generator (120), one or more particle-laden droplets, each particle-laden droplet comprising a particle of the one or more particles surrounded by an aqueous solution, surrounded by a carrier oil (sample emulsion is created where the sample is contained within water within an oil suspension, see [0090] - [0091]);
d. directing the one or more particle-laden droplets through the inlet of the microfluidic device to the fluidic chamber (emulsion droplet is placed into storage chamber, see [0096]) ;
e. immobilizing, by the one or more trapping arrays (118), the one or more particle-laden droplets (particles are trapped within anchoring structure, see Fig. 5 and [0096]); and
However, the current prior art does not teach that the method includes directing, by the droplet generator (120), a continuous flow of carrier oil through the inlet (112) and through the fluidic chamber (114); wherein the continuous flow of carrier oil induces one or more microvortices within the one or more particle-laden droplets at the one or more trapping arrays (118).
However, in the analogous art of particle traps for monitoring and facilitating reactions, Lutz et al. teaches a method of operating a microfluidic device including
directing, by the droplet generator, a continuous flow of fluid through the inlet and through the fluidic chamber (a steady stream of fluid is introduced via the inlet of the chamber, see [0052]);
wherein the continuous flow of fluid induces one or more microvortices within the one or more particle-laden droplets at the one or more trapping arrays (the steady stream of fluid creates an eddy, or microvortex, at the pillar/structure, see Fig. 3 and [0052]).
The modification of a microfluidic system with flow obstacles to include the injection of a carrier fluid to execute fluid operations was known in the art before the effective filing date of the instant invention, as evidenced by Lutz et al, for the benefit of trapping cells within compartments within a microfluidic chamber, see [0011]-[0012]. Therefore, it would have been obvious to modify the method of Xu et al. to modify the fluid flow to continuously flow a fluid to create microvortices within a microfluidic chamber exemplified by Lutz et al. for particle mixing using hydrodynamic fluid forces, see [0034] in Lutz. Further, because the invention of Xu et al. includes the flow of multiple fluids through a droplet generator, specifically a carrier oil fluid, the modification of the method to include the continuous flow of fluid from a source to an inlet of a microfluidic chamber to create microvortices as shown in Lutz et al. would have facilitated the expected result of manipulating particles for analysis.
Further, while the reference of Lutz et al. does not teach that the fluid is a carrier oil, the use of carrier oil to move particles to create a microvortex was known and routine in the art before the effective filing date of the invention, see "Droplet behavior in a Taylor vortex." In the analogous art of inducing vortices in a microfluidic system for droplet operations, Qiao et al. teaches a system where the behavior of droplets are monitored following injection of a carrier phase consisting of oil being injected to alter the Reynolds number of a fluid system.
Therefore, the modification of the working fluid flow of Lutz et al. to incorporate the oil flow of Qiao et al. would have been obvious to a person possessing ordinary skill in the art before the effective filing date of the instant application as the use of oil to manipulate flow physics was known and routine in the art, see Introduction of Qiao et al. The modification of the fluid of Lutz to incorporate the oil of Qiao et al. would have resulted in the expected result of successfully facilitating droplet operations within a series of microvortices in a microfluidic chamber.
Regarding claim 5, modified Xu et al. teaches the method of claim 1, wherein the one or more trapping arrays (118) comprise one or more pockets disposed in an upper interior surface of the fluidic chamber (114), a bottom interior surface of the fluidic chamber (114), or a combination thereof (the pillars contain an indentation in the upper interior surface to accommodate a particle, see Fig. 5 in Xu et al.).
Regarding claim 6, modified Xu et al. teaches the method of claim 1, wherein the continuous flow of carrier oil has a flow rate such that the one or more microvortices induce, for each particle-laden droplet of the one or more particle-laden droplets, spinning of the particle within the particle-laden droplet or orbiting of the particle around a point within the particle-laden droplet (the steady stream flow of fluid induces oscillation of the particles within the fluid trap at the eddy, where the eddy is a particle laden droplet, see [0052] - [0054] in Lutz et al.).
Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over Xu et al. (US 2021/0308678 and Huebner et al. “Static microdroplet arrays” incorporated by reference), and further in view of Lutz et al. (US 2005/0194314), Qiao et al. (“Droplet behavior in a Taylor vortex”).
Regarding claim 2, modified Xu et al. teaches the method of claim 1, wherein the one or more trapping arrays comprise a plurality of pillars separated by gaps (columns for trapping particles, see Fig. 5, and Huebner et al. "Static microdroplet arrays: a microfluidic device for droplet trapping, incubation and release for enzymatic and cell-based assays" as incorporated by reference by Xu et al., see [0096]).
Regarding claim 3, modified Xu et al. teaches the method of claim 2, wherein the plurality of pillars are separated by 2 to 50 μm gaps (the anchoring structures are separated by a gap of ~50 micrometers to trap droplets, see Fig. 3 in Huebner et al., incorporated by reference incorporated by reference in Xu et al.).
Regarding claim 4, modified Xu et al. teaches the method of claim 2, wherein the plurality of pillars are separated by at least three gaps comprising a central gap and at least one lateral gap on each side of the central gap, wherein each particle-laden droplet immobilized by the trapping array (118) blocks the central gap such that the continuous flow of carrier oil flows through the lateral gaps around the particle-laden droplet (the anchoring structures are separated by a central gap to trap particles with gaps on either side to allow continuous fluid flow, see Fig. 2 and "Loading traps with droplets" in Huebner et al., incorporated by reference in Xu et al.).
Conclusion
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/A.N.M./Examiner, Art Unit 1758
/MARIS R KESSEL/Supervisory Patent Examiner, Art Unit 1758