Patent Application 17759070 - METHODS AND SYSTEMS FOR MICROFLUIDIC DEVICE - Rejection

Patent Application 17759070 - METHODS AND SYSTEMS FOR MICROFLUIDIC DEVICE

Title: METHODS AND SYSTEMS FOR MICROFLUIDIC DEVICE MANUFACTURING

Application Information

• Invention Title: METHODS AND SYSTEMS FOR MICROFLUIDIC DEVICE MANUFACTURING
• Application Number: 17759070
• Submission Date: 2025-04-09T00:00:00.000Z
• Effective Filing Date: 2022-07-19T00:00:00.000Z
• Filing Date: 2022-07-19T00:00:00.000Z
• National Class: 156
• National Sub-Class: 272200
• Examiner Employee Number: 92434
• Art Unit: 1745
• Tech Center: 1700

Rejection Summary

• 102 Rejections: 0
• 103 Rejections: 2

Cited Patents

No patents were cited in this rejection.

Office Action Text

    
The arguments and amendments submitted 12/12/2024 have been considered.  The merits of the claims, however, remain unpatentable as set forth below.
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.

Claim 18 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 18 recites an alternative that “said negative pressure being applied for a time period greater than 30 minutes” is recited together with the recitation that “applying said negative pressure comprising applying said negative pressure for at least about 2 hours”.  It is unclear which time period is required for applying negative pressure.  Furthermore, it is unclear whether these are two separate steps of applying negative pressure or not.  For the purpose of examination, claim 1 reads on a single step wherein “applying said negative pressure comprising applying said negative pressure for at least about 2 hours” without any requirement for applying negative pressure for a time period greater than 30 minutes.  
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA  35 U.S.C. 102 and 103 (or as subject to pre-AIA  35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.  
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.

The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
Claims 1 and 3-18 are rejected under 35 U.S.C. 103 as being unpatentable over Roswech (US Patent 8,715,446).
Regarding claim 1, Roswech discloses a method for forming (abstract 'laminate bonding of two non-elastomeric') a microfluidic device (abstract 'solvent-based microfluidic apparatus and method '), comprising: 
a) providing a microfluidic structure and a film (col 7, lines 1-2: 'a polymeric thin film that encloses the microstructures on the first component; see also clm 1, step a); 
b) treating a surface of said microfluidic structure, a surface of said film, or both with a solvent (col 4, lines 49-52 pertain to the application of solvent latency to the bonding of at least two of the same material ...(e.g., Substrate and film); see also col. 8, lines 30-34 and clm 1, step b); 
c) subsequent to (b), pressing said microfluidic structure together with said film (col. 6, line 10) under a first heating condition (col 4, lines 58: 'temperature: equal to or greater than about 30 deg. C' or ‘temperature of about 21 C’ per claim 10; see also col. 6, lines 13-15) to form said microfluidic device comprising said solvent; and 
d) applying a negative pressure to said microfluidic device (col. 5, lines 3-7; col. 6, lines 22-25) under a second heating condition to remove at least a portion of said solvent from b (col 5, lines 3-5: 'a heated platen press may be used in conjunction with a pressure orifice and a vacuum source to suck out excess solvent from open channels or regions'; col. 6, lines 15-17; claims 7 and 10), said negative pressure being applied at a pressure of 0.5 psi to remove at least a portion of said solvent from step b (col 4, lines 62-63: ‘applied pressure: equal to or greater than about 0.5 psi to less than the deformation pressure of the substrate'; see also claim 9), which is equal to 3.45 kPa, and thus within the claimed range, or alternatively ‘between about 1 psi to less than a deformation pressure threshold of the components’ (claim 9), which is equal to 6.89 kPa, and thus also within the claimed range.	
Roswech does not explicitly disclose applying the negative pressure for a time period greater than 30 minutes.
However, Roswech discloses that the second heating step occurs together with the application of negative pressure over a given period of time (col. 6, lines 11-13).  Roswech discloses that this combination of negative pressure and heating applied over a period of time provide the result of removal of excess solvent from regions between the film and substrate which are not intended to be bonded, such as valve seats, reservoirs, or open channels or regions (col 4, line 66 through col 5, line 7), while avoiding deformation of the substrate (col. 5, line 63).  Thus, the upper limit for the negative pressure and the minimum time period for the negative pressure are result-effective variables which prevent undesirable deformation of the substrate or other components within the microfluidic device and provide effective removal of excess solvent.
“[Discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art,” and the presence of such a known result-effective variable would be one … motivation for a person of ordinary skill in the art to experiment to reach another workable product or process.  See In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980), KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007), and also MPEP § 2144.05.II.
In view of Roswech’s disclosure and the above considerations, the selection of a pressure of less than 20 kPa and a time period of greater than 30 minutes for the negative pressure are merely obvious routine optimization of a result-effective variables for one of ordinary skill in the art to prevent undesirable deformation of the substrate while also removing excess solvent from the regions where it is not needed for bonding the film and substrate.

Regarding claim 3, Roswech discloses the method of claim 1. Further, Roswech discloses wherein said treating comprises application of one or more solvents (col 9, Iine 23: 'diluting a solvent and/or blending multiple solvents').

Regarding claim 4, Roswech discloses the method of claim 3. Further, Roswech discloses wherein said one or more solvents include a solvent selected from the group consisting of acetone (col 2, Iine 63 'acetone'), toluene (col 2, Iine 66 'toluene'), and benzene (col 2, Iine 65-66 'aromatic molecules').

Regarding claim 5, Roswech discloses the method of claim 1. Further, Roswech discloses applying a force greater than 0.5 psi (col 4, line 62: 'applied pressure: equal to or greater than about 0.5 psi'), which is equal to 3.45 kilo-Newtons (kN), and thus falls within the claimed range.  

Regarding claim 6, Roswech discloses the method of claim 1. Further, Roswech discloses the use of a temperature greater than 30 deg. C (col 4, line 58: 'temperature: equal to or greater than about 30 deg. C'), thus encompassing the claimed range and rendering it obvious.  A prior art range which encompasses, partially overlaps, or touches the claimed range is sufficient to establish a prima facie case of obviousness, in the absence of any unexpected results.  See MPEP § 2144.05.I and In re Harris, 409 F.3d 1339, 74 USPQ2d 1951 (Fed. Cir. 2005); In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003).

Regarding claim 7, Roswech discloses the method of claim 1. Further, Roswech discloses the use of applied pressure of 0.5 psi (col 4. line 62: 'applied pressure: equal to or greater than about 0.5 psi'), which is equal to 3.45 kPA, and thus falls within the claimed range.

Regarding claim 8, Roswech discloses the method of claim 1. Further, Roswech discloses the use of a temperature of between about 40 to 80 deg. C (claim 7), thus partially overlapping the claimed range and rendering it obvious, as supported by MPEP § 2144.05.I.
 
Regarding claim 9, Roswech discloses the method of claim 8, including the use of temperatures between 70 and 80 deg C (claim 7). However, Roswech does not explicitly disclose removing at least about 75% of said solvent from said microfluidic device. Roswech discloses that heating applied over a period of time provides the result of removal of excess solvent from regions between the film and substrate which are not intended to be bonded, such as valve seats, reservoirs, or open channels or regions (col 4, line 66 through col 5, line 7).  In view of Roswech’s disclosure and the above considerations, the selection of a temperature of at least about 70 deg C to remove at least 75% of the solvent from the device is merely obvious routine optimization of result-effective variables for one of ordinary skill in the art to achieve the result of removing excess solvent from the regions where it is not needed for bonding the film and substrate.

Regarding claim 10, Roswech discloses the method of claim 1. Roswech does not explicitly disclose applying the negative pressure for a time period of at least about 2 hours.  However, Roswech discloses that the second heating step occurs together with the application of negative pressure over a given period of time (col. 6, lines 11-13).  Roswech discloses that this combination of negative pressure and heating applied over a period of time provide the result of removal of excess solvent from regions between the film and substrate which are not intended to be bonded, such as valve seats, reservoirs, or open channels or regions (col 4, line 66 through col 5, line 7), while avoiding deformation of the substrate (col. 5, line 63).  Thus, the minimum time period for the negative pressure is merely obvious routine optimization of a result-effective variable for one of ordinary skill in the art to achieve the result of removing excess solvent from the regions where it is not needed for bonding the film and substrate.
Regarding claim 11, Roswech discloses the method of claim 1. Roswech does not explicitly disclose that applying negative pressure removes at least about 50% of said solvent from said microfluidic device. Roswech discloses that negative pressure applied over a period of time provides the result of removal of excess solvent from regions between the film and substrate which are not intended to be bonded, such as valve seats, reservoirs, or open channels or regions (col 4, line 66 through col 5, line 7), while avoiding deformation of the substrate (col. 5, line 63).  In view of Roswech’s disclosure and the above considerations, applying negative pressure to remove at least about 50% of said solvent from the device is merely obvious routine optimization of a result-effective variable for one of ordinary skill in the art to achieve the result of removing excess solvent from the regions where it is not needed for bonding the film and substrate.

Regarding claim 12, Roswech discloses the method of claim 1. Further, Roswech discloses said applying said negative pressure under said second heating condition reduces separation between said microfluidic structure and said film (col. 6, lines 23-25).
 
Regarding claim 13, Roswech discloses the method of claim 1. Further, Roswech discloses the  microfluidic structure comprises a channel or chamber with a feature size of 0.1 micrometer to about 1000 micrometers (col 7, line 34: '0.1 micrometer to about 1000 micrometers'), thus partially overlapping the claimed range and rendering it obvious, as supported by MPEP § 2144.05.I.

Regarding claim 14, Roswech discloses the method of claim 1.  Further, Roswech discloses that improved bonding can provide the result of increased production yield (col 3, lines 48-50: 'bonding material fills this relief structure, completing the bond. This method allegedly can increase the manufacturing yield of adhesive bonded microfluidic devices'). While Roswech does not disclose removing said solvent increases a yield of a microfluidic device generation process by at least about 25%, it would have been obvious to one of ordinary skill in the art, based on the disclosure of Roswech that reducing the amount of solvent and in turn improving the bond can be used to increase the device generation yields.  In view of Roswech’s disclosure and the above considerations, increasing a yield of the microfluidic device generation process by at least about 25% by removing the solvent is merely obvious routine optimization of a result-effective variable for one of ordinary skill in order to achieve a desired yield level for a particular application.

Regarding claim 15, Roswech discloses the method of claim 1. Further, Roswech discloses that the device includes one or more features (col. 1, lines 39-45; col 7, lines 34-36: 'These features may be, but are not limited to, microchannels, microfluidic pathways, microreservoirs, microreactors'). While Roswech does not explicitly disclose said microfluidic device has a usable feature fraction of at least about 0.5, Roswech does disclose that these microfluidic features can be integrated to a high degree on a microfluidic chip and combined for use in a lab on a chip (col. 1, lines 45-46). In view of Roswech’s disclosure and the above considerations, the claimed usable feature fraction range is merely obvious routine optimization of a result-effective variable for one of ordinary skill in the art in order to have a suitable number of usable features for a particular lab on a chip application. 

Regarding claim 16, Roswech discloses the method of claim 1. Further, Roswech discloses further comprising applying an increased pressure to said microfluidic device, wherein said increased pressure is sufficient to expel at least a portion of said solvent (col 5, lines 3-5: 'press may be used in conjunction with a pressure orifice’; claim 15).

Regarding claim 17, Roswech discloses a method for forming (abstract 'laminate bonding of two non-elastomeric') a microfluidic device (abstract 'solvent-based microfluidic apparatus and method '), comprising: 
a) providing a microfluidic structure and a film (col 7, lines 1-2: 'a polymeric thin film that encloses the microstructures on the first component; see also clm 1, step a); 
b) treating a surface of said microfluidic structure, a surface of said film, or both with a solvent (col 4, lines 49-52 pertain to the application of solvent latency to the bonding of at least two of the same material ...(e.g., Substrate and film); see also col. 8, lines 30-34 and clm 1, step b); 
c) subsequent to (b), pressing said microfluidic structure together with said film (col. 6, line 10) under a first heating condition (col 4, lines 58 'temperature: equal to or greater than about 30 deg. C' or ‘temperature of about 21 C’ per claim 10; see also col. 6, lines 13-15) to form said microfluidic device comprising said solvent, wherein said first heating condition comprises heating to a temperature of at least 30 deg C (col. 4, line 58), thus encompassing the claimed range and rendering it obvious, as supported by MPEP § 2144.05.I; and 
d) applying a negative pressure to said microfluidic device (col. 5, lines 3-7; col. 6, lines 22-25) under a second heating condition to remove at least a portion of said solvent from b (col 5, lines 3-5: 'a heated platen press may be used in conjunction with a pressure orifice and a vacuum source to suck out excess solvent from open channels or regions'; col. 6, lines 15-17; claims 7 and 10), said negative pressure being applied at a pressure of 0.5 psi to remove at least a portion of said solvent from step b (col 4, lines 62-63: ‘applied pressure: equal to or greater than about 0.5 psi to less than the deformation pressure of the substrate'; see also claim 9), which is equal to 3.45 kPa, and thus within the claimed range, or alternatively ‘between about 1 psi to less than a deformation pressure threshold of the components’ (claim 9), which is equal to 6.89 kPa, and thus also within the claimed range, and
said second heating condition comprises heating said microfluidic device to a temperature of between about 40 to 80 deg. C (claim 7), thus partially overlapping the claimed range and rendering it obvious, as supported by MPEP § 2144.05.I.

Regarding claim 18, Roswech discloses a method for forming (abstract 'laminate bonding of two non-elastomeric') a microfluidic device (abstract 'solvent-based microfluidic apparatus and method '), comprising: 
a) providing a microfluidic structure and a film (col 7, lines 1-2: 'a polymeric thin film that encloses the microstructures on the first component; see also clm 1, step a); 
b) treating a surface of said microfluidic structure, a surface of said film, or both with a solvent (col 4, lines 49-52 pertain to the application of solvent latency to the bonding of at least two of the same material ...(e.g., Substrate and film); see also col. 8, lines 30-34 and clm 1, step b); 
c) subsequent to (b), pressing said microfluidic structure together with said film (col. 6, line 10) under a first heating condition (col 4, lines 58: 'temperature: equal to or greater than about 30 deg. C' or ‘temperature of about 21 C’ per claim 10; see also col. 6, lines 13-15) to form said microfluidic device comprising said solvent; and 
d) applying a negative pressure to said microfluidic device (col. 5, lines 3-7; col. 6, lines 22-25) under a second heating condition to remove at least a portion of said solvent from b (col 5, lines 3-5: 'a heated platen press may be used in conjunction with a pressure orifice and a vacuum source to suck out excess solvent from open channels or regions'; col. 6, lines 15-17; claims 7 and 10), said negative pressure being applied at a pressure of 0.5 psi to remove at least a portion of said solvent from step b (col 4, lines 62-63: ‘applied pressure: equal to or greater than about 0.5 psi to less than the deformation pressure of the substrate'; see also claim 9), which is equal to 3.45 kPa, and thus within the claimed range, or alternatively ‘between about 1 psi to less than a deformation pressure threshold of the components’ (claim 9), which is equal to 6.89 kPa, and thus also within the claimed range.
Roswech does not explicitly disclose applying the negative pressure for at least about 2 hours.
However, Roswech discloses that the second heating step occurs together with the application of negative pressure over a given period of time (col. 6, lines 11-13).  Roswech discloses that this combination of negative pressure and heating applied over a period of time provide the result of removal of excess solvent from regions between the film and substrate which are not intended to be bonded, such as valve seats, reservoirs, or open channels or regions (col 4, line 66 through col 5, line 7), while avoiding deformation of the substrate (col. 5, line 63).  Thus, the minimum time period for the negative pressure is a result-effective variable which provides effective removal of excess solvent.
“[Discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art,” and the presence of such a known result-effective variable would be one … motivation for a person of ordinary skill in the art to experiment to reach another workable product or process.  See In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980), KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007), and also MPEP § 2144.05.II.
In view of Roswech’s disclosure and the above considerations, the selection of a time period of at least about 2 hours for the negative pressure is merely obvious routine optimization of a result-effective variable for one of ordinary skill in the art in order to remove excess solvent from the regions where it is not needed for bonding the film and substrate.

Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Roswech, as applied to claim 1 above, in view of Hung (US Patent 9,845,499).

Regarding claim 2, Roswech discloses the method of claim 1.  Further, Roswech discloses wherein said microfluidic structure comprises a microchannel, a plurality of microchambers, or a combination thereof (col 7, lines 34-36). However, Roswech does not disclose a plurality of siphon apertures. 
Hung discloses microfluidic device with siphon apertures (abstract: 'A microfluidic device can have a plurality of microchambers connected to a microchannel via siphon apertures'). In view of the fact that both Roswech and Hung relate to microfluidic devices, it would have been obvious to one of ordinary skill in the art to modify the disclosure of Roswech with the disclosure of Hung and use siphon apertures in order to better control the flow of fluid through the microfluidic device.
Response to Arguments
Applicant's arguments with respect to the prior art rejections of the claims have been fully considered, are primarily drawn toward the claims as amended with the new combination of features in claim 1, and have been addressed in the rejection of claim 1 above.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/JRS/
Examiner
Art Unit 1745



/PHILIP C TUCKER/Supervisory Patent Examiner, Art Unit 1745