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 .
Claim Interpretation
Examiner notes that claims 2-15 all rely on a fluidic contact angle of an unspecified fluid in a microfluidic channel of an unspecified material. Further, the fluid within the channel is not a positively recited claim element and therefore does not carry patentable weight in an apparatus claim. Examiner notes because the microfluidic device of Iijima, et. al. (WO 2018147462 A1) teaches the structural elements of claim 1 (described in detail below), it is fully capable of having the dimensions as applied in claims 2-15 that are ultimately based the intended use of the microfluidic device with an unspecified fluid having a fluidic contact angle.
In favor of compact prosecution, examiner has included additional examination of the claims in view of Iijima, et. al. (WO 2018147462 A1) and Iijima, et. al. (WO 2018147462 A1) in view of Chung, et. al. (US 20050133101 A1) in order to arrive that the same structural elements as defined by the intended use of the microfluidic device with an unspecified fluid having a fluidic contact angle.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 2-13 and 15 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 2 recites the limitation "a fluidic contact angle" in line 3 of the claim. Examiner notes fluidic contact angles are determined based on a plurality of factors, and Applicant themselves points in paragraphs 0012-0013 of the specification of the instant application the same fact. Because no specific fluid or specific material is recited or positively claimed, the scope of the claim remains indefinite because there is an indefinite combination of fluids and materials all of which will contribute to a slightly different fluidic contact angle.
Claim 3 is rejected based on its dependence to claim 2.
Claim 4 recites the limitation "a fluidic contact angle" in line 3 of the claim. Examiner notes fluidic contact angles are determined based on a plurality of factors, and Applicant themselves points in paragraph 0021 of the specification of the instant application the same fact. Because no specific fluid or specific material is recited or positively claimed, the scope of the claim remains indefinite because there is an indefinite combination of fluids and materials all of which will contribute to a slightly different fluidic contact angle.
Claims 5-11 are rejected based on their dependence to claim 4.
Claim 9 recites the limitation "a fluidic contact angle" in lines 3-4 and 5-6 of the claim. Examiner notes fluidic contact angles are determined based on a plurality of factors, and Applicant themselves points in paragraph 0021 of the specification of the instant application the same fact. Because no specific fluid or specific material is recited or positively claimed, the scope of the claim remains indefinite because there is an indefinite combination of fluids and materials all of which will contribute to a slightly different fluidic contact angle.
Claim 10 is rejected based on its dependency to claim 9.
Claim 10 recites the limitation "a fluidic contact angle" in lines 2 and 3-4 of the claim. Examiner notes fluidic contact angles are determined based on a plurality of factors, and Applicant themselves points in paragraph 0021 of the specification of the instant application the same fact. Because no specific fluid or specific material is recited or positively claimed, the scope of the claim remains indefinite because there is an indefinite combination of fluids and materials all of which will contribute to a slightly different fluidic contact angle.
Claim 11 recites the limitation "a fluidic contact angle" in lines 3 of the claim. Examiner notes fluidic contact angles are determined based on a plurality of factors, and Applicant themselves points in paragraph 0021 of the specification of the instant application the same fact. Because no specific fluid or specific material is recited or positively claimed, the scope of the claim remains indefinite because there is an indefinite combination of fluids and materials all of which will contribute to a slightly different fluidic contact angle.
Claim 12 recites the limitation "a fluidic contact angle" in lines 7-8 of the claim. Examiner notes fluidic contact angles are determined based on a plurality of factors, and Applicant themselves points in paragraph 0021 of the specification of the instant application the same fact. Because no specific fluid or specific material is recited or positively claimed, the scope of the claim remains indefinite because there is an indefinite combination of fluids and materials all of which will contribute to a slightly different fluidic contact angle.
Claim 13 is rejected based on its dependency to claim 12.
Claim 15 recites the limitation "a fluidic contact angle" in lines 3 of the claim. Examiner notes fluidic contact angles are determined based on a plurality of factors, and Applicant themselves points in paragraph 0021 of the specification of the instant application the same fact. Because no specific fluid or specific material is recited or positively claimed, the scope of the claim remains indefinite because there is an indefinite combination of fluids and materials all of which will contribute to a slightly different fluidic contact angle.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 15 rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends. Claim 15, recites the limitation “the microfluidic device of claim 0” in the first line of the claim. Examiner believes this should read “the microfluidic device of claim 14” based on the context of the claim set up and the specification and will be examined as such.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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 patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3 and 12-13 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Iijima, et. al. (WO 2018147462 A1; citations made with respect to attached English machine translation and original language copy).
Regarding claim 1, Iijima teaches a device that focuses on how microstructures, specifically microchannels, influence flow profile through a microfluidic device [par. 0009]. Iijima teaches a microfluidic device comprising a first channel 16 having a first width, a second channel 110 having a second width greater than the first width, and a transition channel 17 having a first end fluidically connected to the first channel (see side closest to angle 19) and a second end fluidically connected to the second channel (not pictured in detail, but understood because channel 16 leads to channel 110, each with an set width as seen in Fig. 12a, 12b, and channel 16 is directly connected to channel 110 through widening channel 17) [Fig. 11, 12a-c; par. 0027-0028]. Iijima teaches wherein the transition channel 17 expands in width from the first width to the second width as seen by Fig. 12c which depicts the first width of channel 17 connected to the first channel 16. While the second width of channel 17 connected to the second channel 110 is not shown in detail, it is understood by combining the concepts shown in Fig. 12a-c, channel 17 stops expanding and terminates to form second channel 110.
Examiner notes the limitation so as to promote fluid flow from the first channel to the second channels is drawn to a functional limitation of the expanding and branching channel, and because Iijima teaches an expanding channel 17 that expands from a narrower first channel to a wider channel, the expanding channel 17 is functionally capable to promote fluid flow from the first channel to the second channels. Further, Iijima teaches the widening.
Regarding claim 2, Iijima teaches wherein the transition channel 17 linearly expands in width from the width of the first channel to the sum of the widths of the second channels at an angle as seen by the linear, symmetrical extension of the first channel 16 to the second channel 110 through the transition channel [Fig. 12c].
Iijima does teach the channel 17 expands at an angle 24a, 24b at a degree between 90° to 180°. Based on the description of the angle of paragraph 0012-0013 of the specification of the instant application, the corresponding angle in the instant application to the angles 24a, 24b of Iijima corresponds to approximately 170°. Iijima teaches angle 24a, 24b expands in a linear fashion between 90° to 180° [Fig. 11; par. 0083]. Therefore, if an aqueous fluid is used, the angle should expand no greater than 20° (as per the specification of the instant application, par. 0012-0013) making the corresponding angle 24a, 24b of Iijima be around 170° which is between 90° to 180°. Therefore, the transition channel linearly expands in width from the first width to the second width at an angle no greater than two times a difference between 90 degrees and a fluidic contact angle.
Regarding claim 3, as explained above in claim 2, Iijima teaches the channel 17 expands at an angle 24a, 24b at a degree between 90° to 180°. Based on the description of the angle of paragraph 0012-0013 of the specification of the instant application, the corresponding angle in the instant application to the angles 24a, 24b of Iijima corresponds to approximately 170°. Iijima teaches angle 24a, 24b expands in a linear fashion between 90° to 180° [Fig. 11; par. 0083]. Therefore, if an aqueous fluid is used, the angle should expand no greater than 20° (as per the specification of the instant application, par. 0012-0013) making the corresponding angle 24a, 24b of Iijima be around 170° which is between 90° to 180°. Therefore, the angle is no greater than 20 degrees.
Regarding claim 12, Iijima teaches a device that focuses on how microstructures, specifically microchannels, influence flow profile through a microfluidic device [par. 0009]. Iijima teaches a microfluidic device comprising a first channel 16 having a first width, a second channel 110 having a second width greater than the first width, and a transition channel 17 having a first end fluidically connected to the first channel (see side closest to angle 19) and a second end fluidically connected to the second channel (not pictured in detail, but understood because channel 16 leads to channel 110, each with an set width as seen in Fig. 12a, 12b, and channel 16 is directly connected to channel 110 through widening channel 17) [Fig. 11, 12a-c; par. 0027-0028]. Iijima teaches wherein the transition channel 17 expands in width from the first width to the second width as seen by Fig. 12c which depicts the first width of channel 17 connected to the first channel 16. While the second width of channel 17 connected to the second channel 110 is not shown in detail, it is understood by combining the concepts shown in Fig. 12a-c, channel 17 stops expanding and terminates to form second channel 110.
Iijima teaches wherein the transition channel 17 linearly expands in width from the width of the first channel to the sum of the widths of the second channels at an angle as seen by the linear, symmetrical extension of the first channel 16 to the second channel 110 through the transition channel [Fig. 12c].
Iijima does teach the channel 17 expands at an angle 24a, 24b at a degree between 90° to 180°. Based on the description of the angle of paragraph 0012-0013 of the specification of the instant application, the corresponding angle in the instant application to the angles 24a, 24b of Iijima corresponds to approximately 170°. Iijima teaches angle 24a, 24b expands in a linear fashion between 90° to 180° [Fig. 11; par. 0083]. Therefore, if an aqueous fluid is used, the angle should expand no greater than 20° (as per the specification of the instant application, par. 0012-0013) making the corresponding angle 24a, 24b of Iijima be around 170° which is between 90° to 180°. Therefore, the transition channel linearly expands in width from the first width to the second width at an angle no greater than two times a difference between 90 degrees and a fluidic contact angle.
Regarding claim 13, as explained above in claim 12, Iijima teaches the channel 17 expands at an angle 24a, 24b at a degree between 90° to 180°. Based on the description of the angle of paragraph 0012-0013 of the specification of the instant application, the corresponding angle in the instant application to the angles 24a, 24b of Iijima corresponds to approximately 170°. Iijima teaches angle 24a, 24b expands in a linear fashion between 90° to 180° [Fig. 11; par. 0083]. Therefore, if an aqueous fluid is used, the angle should expand no greater than 20° (as per the specification of the instant application, par. 0012-0013) making the corresponding angle 24a, 24b of Iijima be around 170° which is between 90° to 180°. Therefore, the angle is no greater than 20 degrees.
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 4-15 are rejected under 35 U.S.C. 103 as being unpatentable over Iijima, et. al. (WO 2018147462 A1; citations made with respect to attached English machine translation and original language copy) in view of Chung, et. al. (US 20050133101 A1).
Regarding claim 4, Iijima teaches wherein the transition channel 17 non-linearly expands in width from the width of the first channel 16 to the second channel 110 at an angle as seen by the non-linear, asymmetrical extension of the first channel 16 to the second channel 110 through the transition channel wherein one side comprising wall 16a remains linear and the other side comprising wall 16b expands at an angle[Fig. 23a, 23b].
Iijima is silent to wherein the increasing angle is based on a fluidic contact angle.
Chung teaches a fluid control device and method for the control of fluid through microfluidic channels based on capillary forces (Abstract). Chung teaches a device wherein channel 120 expands in width to from reaction chamber 110 solely through the capillary action of the fluid interacting with the surface of the microfluidic channel [Fig. 1A; par. 0036, 0042, 0046]. Chung further teaches the flow is further influenced by the shape of the fluid droplet that creates a contact angle with the solid surface of the microchannel [par. 0048]. Going forward, the contact angle of the droplet with respect to the solid surface will be represented by ϴ. Chung teaches ϴ is influenced by a plurality of factors including but not limited to the material of the surface and geometry of the single or multiple surfaces [Fig. 2A-D; par. 0048-0050]. Chung teaches when a channel expands, as seen in Fig. 3A by an angle of β, there is a change in capillary force [par. 0051-0054]. When turning to Fig. 3C, Chung teaches wherein as the ϴ changes, in order for the capillary force to remain positive and thus move the fluid forward in the microfluidic device the β must be based on a fluidic contact angle [Fig. 3c; par. 0054-0056]. Chung teaches the angle at which the channel expands is in part impacted by the contact angle and in order to keep fluid moving forward under capillary pressure alone, the expansion angle must be determined based on the fluid contact angle [par. 0052-0053].
It would have been obvious for one of ordinary skill in the art before the effective filing date of the invention to modify the angle of the expanded channel of Chun to follow the principles set forth by Chung in order to keep the capillary pressure positive and continue to move the liquid forward in the microfluidic system without applying external pressure. Because both systems use capillary forces to move liquid through an expanding microfluidic channel modifying the angle of expansion as provided by Chung, provides likewise sought functionality with reasonable expectation of success. MPEP 2143(I)(G).
Regarding claim 5, Modified Iijima in view of Chung teaches when a channel expands, as seen in Fig. 3A by an angle of β, there is a change in capillary force [Chung, par. 0051-0054]. When turning to Fig. 3C, Chung teaches wherein the contact angle ϴ changes, the increasing angle (β) maintains a specified positive net capillary fluidic force along a length of the transition channel [Fig. 3c; par. 0054-0056]. Chung teaches the angle at which the channel expands is in part impacted by the contact angle and in order to keep fluid moving forward under capillary pressure alone, the expansion angle must be determined based on the fluid contact angle [par. 0052-0053].
Regarding claim 6, Modified Iijima in view of Chung teaches in addition to expansion angle, the length of the increasing (or decreasing) channel must also be considered and properly combined [Chung, par. 0074].
Modified Iijima is silent to wherein the increasing angle minimizes the length of the transition channel along which the transition channel expands in width.
Chung teaches ultimately what drives fluid forward in a microfluidic channel is based on an overall positive capillary force value as seen in Fig. 3B and 3C [par. 0069]. This means height, width, change of width (increasing or decreasing angle), and length of the channel amongst other variables influence that overall net positive capillary force that drive the fluid forward [par. 0069-0074]. Chung teaches wherein a channel width decreases, the length of the channel must increase [par. 0074].
Therefore, Chung teaches wherein the channel length is a result-effective variable. Specifically, Chung teaches angle at which the channel increases or decreases will ultimately influence the length of the channel [par. 0074]. Since this particular parameter is recognized as a result-effective variable (i.e. a variable which achieves a recognized result), the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See MPEP 2144.05 (II)(A). Therefore, it would have been obvious to one having ordinary skill in the art prior to the effective filing date of the claimed invention to minimizes the length of the transition channel along which the transition channel expands in width.
Regarding claim 7, Modified Iijima in view of Chung teaches when a channel expands, as seen in Fig. 3A by an angle of β, there is a change in capillary force [Chung, par. 0051-0054]. When turning to Fig. 3C [Chung], Chung teaches wherein the contact angle ϴ changes, the increasing angle (β) is determined to maintain a specified positive net capillary fluidic force [Chung, Fig. 3c; par. 0054-0056]. Chung teaches the angle at which the channel expands is in part impacted by the contact angle and in order to keep fluid moving forward under capillary pressure alone, the expansion angle must be determined based on the fluid contact angle as well as height and width of the channel [Chung, par. 0051-0055]. Specifically Chung teaches Equation 1 and Equation 2 for the expansion of the channel along a width (Eqn. 1) while considering and upper and lower surface (Eqn. 2) wherein the specified positive net capillary fluidic force is based on a positive first term contributed by a floor and a ceiling of the transition channel between sidewalls of the transition channel, as seen represented by the term containing W in Eqn. 1 and 2, and negative second term contributed by the sidewalls of the transition channel between the floor and the ceiling of the transition channel, as seen represented by the term containing H in Eqn. 1 and 2 [Chung, par. 0051-0055].
Regarding claim 8, Modified Iijima in view of Chung teaches wherein the positive first term and the negative first term are each further based on fluidic surface tension as seen by both terms in the equation being treated by surface tension coefficient of the fluid, represented by σ [Chung, par. 0051-0055]. As seen in Fig. 3B and 3C of Chung, each individual value is fine tuned to create an overall net positive the influence a forward flow [Chung, par. 0056].
Regarding claim 9, Modified Chun in view of Chung teaches when a channel expands, as seen in Fig. 3A by an angle of β, there is a change in capillary force [Chung, par. 0051-0054]. When turning to Fig. 3C [Chung], Chung teaches wherein the contact angle ϴ changes, the increasing angle (β) is determined to maintain a specified positive net capillary fluidic force [Chung, Fig. 3c; par. 0054-0056]. Chung teaches the angle at which the channel expands is in part impacted by the contact angle and in order to keep fluid moving forward under capillary pressure alone, the expansion angle must be determined based on the fluid contact angle as well as height and width of the channel [Chung, par. 0051-0055]. Specifically Chung teaches Equation 1 and Equation 2 for the expansion of the channel along a width (Eqn. 1) while considering and upper and lower surface (Eqn. 2) wherein the specified positive net capillary fluidic force is based on a positive first term and a negative second term, wherein the positive first term is based on a width of the transition channel and the fluidic contact angle, as seen represented by the term containing W and ϴ (contact angle) in Eqn. 1 and 2, wherein the negative second term is based on a height of the transition channel, the fluidic contact angle, and the increasing angle at which the transition channel non-linearly expands in width, as seen represented by the term containing H and ϴ (contact angle) and β (increasing angle) in Eqn. 1 and 2 [Chung, par. 0051-0055]. Further Chung teaches wherein the positive first term and the negative first term are each further based on fluidic surface tension as seen by both terms in the equation being treated by surface tension coefficient of the fluid, represented by σ [Chung, par. 0051-0055]. As seen in Fig. 3B and 3C of Chung, each individual value is fine tuned to create an overall net positive the influence a forward flow [Chung, par. 0056].
Regarding claim 10, Modified Iijima in view of Chung teaches in addition to expansion angle, the length of the increasing (or decreasing) channel must also be considered and properly combined [Chung, par. 0074]. Chung teaches these additional conditions are described by Equations 1 and 2 that define the capillary forces that influence movement of the fluid through the expanding channel wherein as long as the overall pressure remains positive, there will be a forward fluid flow [Chung, par. 0054]. Chung teaches as seen in the Equations 1 and 2 that surface tension (σ), fluidic contact angle (ϴ), and increasing angle (β) all influence the overall positive pressure along with the channel height (H) and width (W) [Chung, par. 0051-0055]. Chung teaches wherein the positive first term and the negative first term are each further based on fluidic surface tension as seen by both terms in the equation being treated by surface tension coefficient of the fluid, represented by σ [Chung, par. 0051-0055]. As seen in Fig. 3B and 3C of Chung, each individual value is fine tuned to create an overall net positive the influence a forward flow [Chung, par. 0056].
Modified Iijima is silent to wherein the positive first term is based on a cosine of the fluidic contact angle and wherein the negative second term is based on a cosine of a sum of the fluidic contact angle and one half of the increasing angle at which the transition channel non-linearly expands in width from the first width to the second width.
Chung teaches ultimately what drives fluid forward in a microfluidic channel is based on an overall positive capillary force value as seen in Fig. 3B and 3C [par. 0069]. This means height, width, increasing angle, surface tension, and contact angle amongst other variables influence that overall net positive capillary force that drive the fluid forward [par. Fig. 3A-C; 0051-0055]. Further, Equations 1 and 2 of Chung teach a change in the pressure of the capillary forces and not the force of the fluid itself is experiencing. Because force and pressure are related values, an overall positive pressure as taught by Chung to keep the fluid moving forward means and overall positive force is also needed (since an area will always be positive).
Therefore, Chung teaches wherein the pressure and therefore the force is a result-effective variable. Specifically, Chung teaches a pressure, and by relation force, is influenced by height, width, surface tension, contact angle, and increasing angle as per the pressure equations 1 and 2 [par. 0051-0055]. Since this particular parameter is recognized as a result-effective variable (i.e. a variable which achieves a recognized result), the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See MPEP 2144.05 (II)(A). Therefore, it would have been obvious to one having ordinary skill in the art prior to the effective filing date of the claimed invention to take Equations 1 and 2 along with the relevant variables associated with equations 1 and 2 to arrive at the claimed mathematical relationship wherein the positive first term is based on a cosine of the fluidic contact angle and wherein the negative second term is based on a cosine of a sum of the fluidic contact angle and one half of the increasing angle at which the transition channel non-linearly expands in width from the first width to the second width.
Regarding claim 11, Modified Iijima in view of Chung teaches Equations 1 and 2 define the capillary forces that influence movement of the fluid through the expanding channel wherein as long as the overall pressure remains positive, there will be a forward fluid flow [par. 0054]. Chung teaches as seen in the Equations 1 and 2 that surface tension (σ), fluidic contact angle (ϴ), and increasing angle (β) all influence the overall positive pressure along with the channel height (H) and width (W) [Chung, par. 0051-0055].
Modified Iijima in view of Chung is silent to wherein the specified positive net capillary fluidic force is equal to
2
γ
w
cos
θ
+
h
cos
θ
θ
+
ϕ
2
.
Chung teaches ultimately what drives fluid forward in a microfluidic channel is based on an overall positive capillary force value as seen in Fig. 3B and 3C [par. 0069]. This means height, width, increasing angle, surface tension, and contact angle amongst other variables influence that overall net positive capillary force that drive the fluid forward [par. Fig. 3A-C; 0051-0055]. Further, Equations 1 and 2 of Chung teach a change in the pressure of the capillary forces and not the force of the fluid itself is experiencing. Because force and pressure are related values, an overall positive pressure as taught by Chung to keep the fluid moving forward means and overall positive force is also needed (since an area will always be positive).
Therefore, Chung teaches wherein the pressure and therefore the force is a result-effective variable. Specifically, Chung teaches a pressure, and by relation force, is influenced by height, width, surface tension, contact angle, and increasing angle as per the pressure equations 1 and 2 [par. 0051-0055]. Since this particular parameter is recognized as a result-effective variable (i.e. a variable which achieves a recognized result), the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See MPEP 2144.05 (II)(A). Therefore, it would have been obvious to one having ordinary skill in the art prior to the effective filing date of the claimed invention to take Equations 1 and 2 along with the relevant variables associated with equations 1 and 2 to arrive at the claimed equations wherein the specified positive net capillary fluidic force is equal to
2
γ
w
cos
θ
+
h
cos
θ
θ
+
ϕ
2
.
Regarding claim 14, Iijima teaches a device that focuses on how microstructures, specifically microchannels, influence flow profile through a microfluidic device [par. 0009]. Iijima teaches a microfluidic device comprising a first channel 16 having a first width, a second channel 110 having a second width greater than the first width, and a transition channel 17 having a first end fluidically connected to the first channel (see side closest to angle 19) and a second end fluidically connected to the second channel (not pictured in detail, but understood because channel 16 leads to channel 110, each with an set width as seen in Fig. 12a, 12b, and channel 16 is directly connected to channel 110 through widening channel 17) [Fig. 11, 12a-c; par. 0027-0028]. Iijima teaches wherein the transition channel 17 expands in width from the first width to the second width as seen by Fig. 12c which depicts the first width of channel 17 connected to the first channel 16. While the second width of channel 17 connected to the second channel 110 is not shown in detail, it is understood by combining the concepts shown in Fig. 12a-c, channel 17 stops expanding and terminates to form second channel 110.
Iijima teaches wherein the transition channel 17 non-linearly expands in width from the width of the first channel 16 to the second channel 110 at an angle as seen by the non-linear, asymmetrical extension of the first channel 16 to the second channel 110 through the transition channel wherein one side comprising wall 16a remains linear and the other side comprising wall 16b expands at an angle[Fig. 23a, 23b].
Iijima is silent to the increasing angle maintaining a specified positive net capillary fluidic force along a length of the transition channel.
Chung teaches a fluid control device and method for the control of fluid through microfluidic channels based on capillary forces (Abstract). Chung teaches a device wherein channel 120 expands in width to from reaction chamber 110 solely through the capillary action of the fluid interacting with the surface of the microfluidic channel [Fig. 1A; par. 0036, 0042, 0046]. Chung further teaches the flow is further influenced by the shape of the fluid droplet that creates a contact angle with the solid surface of the microchannel [par. 0048]. Going forward, the contact angle of the droplet with respect to the solid surface will be represented by ϴ. Chung teaches ϴ is influenced by a plurality of factors including but not limited to the material of the surface and geometry of the single or multiple surfaces [Fig. 2A-D; par. 0048-0050]. Chung teaches when a channel expands, as seen in Fig. 3A by an angle of β, there is a change in capillary force [par. 0051-0054]. When turning to Fig. 3C, Chung teaches wherein as the ϴ changes, in order for the capillary force to remain positive and thus move the fluid forward in the microfluidic device the β must be based on a fluidic contact angle [Fig. 3c; par. 0054-0056]. Chung teaches the angle at which the channel expands is in part impacted by the contact angle and in order to keep fluid moving forward under capillary pressure alone, the expansion angle must be determined based on the fluid contact angle [par. 0052-0053].
Chung teaches when a channel expands, as seen in Fig. 3A by an angle of β, there is a change in capillary force [Chung, par. 0051-0054]. When turning to Fig. 3C, Chung teaches wherein the contact angle ϴ changes, the increasing angle (β) maintains a specified positive net capillary fluidic force along a length of the transition channel [Fig. 3c; par. 0054-0056]. Chung teaches the angle at which the channel expands is in part impacted by the contact angle and in order to keep fluid moving forward under capillary pressure alone, the expansion angle must be determined based on the fluid contact angle [par. 0052-0053].
It would have been obvious for one of ordinary skill in the art before the effective filing date of the invention to modify the angle of the expanded channel of Chun to follow the principles set forth by Chung to maintain a specified positive net capillary fluidic force in order to keep the capillary pressure positive and continue to move the liquid forward in the microfluidic system without applying external pressure. Because both systems use capillary forces to move liquid through an expanding microfluidic channel modifying the angle of expansion as provided by Chung, provides likewise sought functionality with reasonable expectation of success. MPEP 2143(I)(G).
Regarding claim 15, Modified Iijima in view of Chung teaches Equations 1 and 2 define the capillary forces that influence movement of the fluid through the expanding channel wherein as long as the overall pressure remains positive, there will be a forward fluid flow [par. 0054]. Chung teaches as seen in the Equations 1 and 2 that surface tension (σ), fluidic contact angle (ϴ), and increasing angle (β) all influence the overall positive pressure along with the channel height (H) and width (W) [Chung, par. 0051-0055].
Modified Iijima in view of Chung is silent to wherein the specified positive net capillary fluidic force is equal to
2
γ
w
cos
θ
+
h
cos
θ
θ
+
ϕ
2
.
Chung teaches ultimately what drives fluid forward in a microfluidic channel is based on an overall positive capillary force value as seen in Fig. 3B and 3C [par. 0069]. This means height, width, increasing angle, surface tension, and contact angle amongst other variables influence that overall net positive capillary force that drive the fluid forward [par. Fig. 3A-C; 0051-0055]. Further, Equations 1 and 2 of Chung teach a change in the pressure of the capillary forces and not the force of the fluid itself is experiencing. Because force and pressure are related values, an overall positive pressure as taught by Chung to keep the fluid moving forward means and overall positive force is also needed (since an area will always be positive).
Therefore, Chung teaches wherein the pressure and therefore the force is a result-effective variable. Specifically, Chung teaches a pressure, and by relation force, is influenced by height, width, surface tension, contact angle, and increasing angle as per the pressure equations 1 and 2 [par. 0051-0055]. Since this particular parameter is recognized as a result-effective variable (i.e. a variable which achieves a recognized result), the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See MPEP 2144.05 (II)(A). Therefore, it would have been obvious to one having ordinary skill in the art prior to the effective filing date of the claimed invention to take Equations 1 and 2 along with the relevant variables associated with equations 1 and 2 to arrive at the claimed equations wherein the specified positive net capillary fluidic force is equal to
2
γ
w
cos
θ
+
h
cos
θ
θ
+
ϕ
2
.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Jung, et. al. (KR 20040043897 A) teaches a microfluidic device wherein the fluidic flow through the microchip is controlled through surface-tension [par. 0028] wherein expanding microchannels are analyzed [Fig. 2i, 2k].
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/M.T.H./Examiner, Art Unit 1758
/MARIS R KESSEL/Supervisory Patent Examiner, Art Unit 1758
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