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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 07/08/2025 has been entered.
Remarks
This office action fully acknowledges Applicant’s arguments and amendments filed 8 July 2025.
Claims 1, 3-4, and 6-10 are pending.
Claims 2, 5, and 11-15 are cancelled.
No claims are withdrawn.
No new claims are added.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1, 3-4, and 6-10 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 1 is amended to recite “the microfluidic chip is configured and arranged such that the sequential liquid flow from the first liquid storage tank through the first flow channel and from the second liquid storage tank through the second flow channel to the detection area each occurs in the absence of external centrifugal force or an applied air pressure”.
Applicant’s alleged support for this amendment is the specification describing the device as controlling flow under the action of gravity and “without additional power equipment such as a micropump, an injection pump, an extrusion device, a centrifugal force device, etc.” as in paras. [0010] and [0064] of Applicant’s instant pre-grant publication US 2022/0226813 A1.
However, Applicant’s positive assertion that the device may be used to cause flow under force of gravity does not provide basis for the exclusion of other forces. Further Applicant’s instant specification merely excludes equipment such as pumps and centrifugal devices, wherein air pressure may be introduced through a means other than a pump, such as a compressed gas cylinder, and a centrifugal force may be caused by a means other than a centrifugal device, such as spinning the chip by hand.
Thus, Applicant’s instant specification does not provided basis for the amendment to Claim 1 filed 07/08/2025 requiring that “the microfluidic chip is configured and arranged such that the sequential liquid flow from the first liquid storage tank through the first flow channel and from the second liquid storage tank through the second flow channel to the detection area each occurs in the absence of external centrifugal force or an applied air pressure”, and Claim 1 is thereby rejected under 35 USC 112a.
Claim Rejections - 35 USC § 102
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 3, and 9-10 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Lin et al. (US 2016/0144363 A1), hereinafter “Lin”.
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Regarding Claim 1, Lin teaches a microfluidic chip ([0009]: “microfluidic device”), comprising a substantially flat, disk-shaped substrate (Fig. 1A) having an upper side and a lower side and comprising:
a detection area 450 (Fig. 3C and [0048]: “detection chambers 450”),
a first liquid storage tank 50 and a second liquid storage tank 420 (Fig. 3C),
a first flow channel 440, wherein the first liquid storage tank 50 and the second liquid storage tank 420 are respectively in liquid communication with the detection area 450 through the first flow channel (Fig. 3C shows the overflow channel 440 as in liquid communication with the detection area 450.),
a second flow channel (See Figs. 6A-C which show second flow channels connecting subsidiary chambers such as 510A to the overflow channel 440.), wherein the second liquid storage tank is in liquid communication with the detection area through the second flow channel (Fig. 3C shows the detection area 450 as in liquid communication with the channel of subsidiary element 50, containing the second liquid storage tank.),
a first opening in the first liquid storage tank providing direct liquid communication between the first liquid storage tank and a first end of the first flow channel (Fig. 6A shows an embodiment wherein a single port connects a single member of a second storage tank 510A to the first channel which connects to the overflow channel 440.),
a second opening in the second liquid storage tank providing direct liquid communication between the second liquid storage tank and a first end of the second flow channel (Fig. 3C shows the chamber 420 as having an opening directly connected to a first end of the overflow channel 440.);
wherein the first opening and the second opening are configured and arranged in the substrate such that a first direction of liquid flow from the first liquid storage tank through the first opening and into the first flow channel is opposite to a second direction of liquid flow from the second liquid storage tank through the second opening and into the second flow channel (Fig. 3C shows the ports to the second tank 11 and the first tank 50 most closely connected to the chamber 470 as being opposite one another.),
such that liquid flow from the first liquid storage tank and from the second liquid storage tank to the detection area occurs sequentially as the substrate rotates about the central axis of the substrate (Para. [0058] discussed how activation of the drive unit immediately causes reagents contained in subsidiary elements 50 to flow into the detection chambers 450. Further, para. [0074] discusses delayed actuation of the fluid contained in second storage tank 420 via compression and decompression of air in the air chamber 430. Thus, Lin teaches a device capable of sequential fluid flow commensurately as claimed.),
as in Claim 1.
Further regarding Claim 1, given the commensurate arrangement of channels and chambers of Lin as in the instant Claim 1, Lin inherently teaches the microfluidic chip discussed above configured and arranged such that sequential liquid flow from the first liquid storage tank through the first flow channel and from the second liquid storage tank through the second flow channel to the detection area each occurs in the absence of external centrifugal force or an applied air pressure, as in Claim 1. Therein, it is noted that the device of Lin may be operated to cause flow via gravity by orienting the chip on its side and rotating the chip. Further, while centrifugal force is discussed by Lin as necessary to overcome certain capillary restrictions, the use of the device with non-polar solvents having minimal surface tension would not require significant centrifugal force to overcome such constrictions optimized for aqueous samples having significant surface tension ([0064-0065]). Additionally, even if particular forces are maintained as necessary for overcoming constrictions in Lin, said forces need not be centrifugal in nature and may arise from manipulation in the hands of a user.
Regarding Claim 3, the prior art meets the limitations of Claim 1 as discussed above. Further, Lin teaches the microfluidic chip discussed above further comprising a waste liquid tank 470, wherein the detection area 450 is in liquid communication with the waste liquid tank 470 (Fig. 3C and [0055]: “The waste chamber 470…is configured to accept excess fluid such as the first test solution.”), as in Claim 3.
Regarding Claim 9, the prior art meets the limitations of Claim 1 as discussed above. Further, Lin teaches the microfluidic chip discussed above wherein the detection area comprises a detection element therein ([0048]: “The detection chamber 450…is used to contain a test material, such as a…test strip.”), as in Claim 9.
Regarding Claim 10, the prior art meets the limitations of Claim 9 as discussed above. Further, Lin teaches the microfluidic chip discussed above wherein the detection element is selected from an electrochemical sensor or an optical test paper ([0048]: “The detection chamber 450…is used to contain a test material, such as a…test strip.”), as in Claim 10.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 4 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Lin, as applied to Claims 1, 3 and 9-10 above, in view of Ukita et al. (Ukita, Yoshiaki; et al., “Stacked centrifugal microfluidic device with three-dimensional microchannel networks and multifunctional capillary bundle structures for immunoassay,” 20 May 2012, Sensors and Actuators B: Chemical, Vol. 166-167, pages 898-906.), referred to hereinafter as “Ukita.”
Regarding Claim 4, the prior art meets the limitations of Claim 1 as discussed above. Further, Lin teaches the microfluidic chip discussed above wherein:
The first flow channel is in liquid communication with a third flow channel and the third flow channel is in liquid communication with the detection area wherein liquid communication between the first liquid storage tank and the detection area occurs through the first flow channel and the third flow channel (See the annotated Fig. 3C in the 35 USC 102 section above.),
the second flow channel is in liquid communication with the third flow channel wherein liquid communication between the second liquid storage tank and the detection area occurs through the second flow channel and the third flow channel (See the annotated Fig. 3C in the 35 USC 102 section above.),
as in Claim 4.
Further regarding Claim 4, Lin does not specifically teach the detection area as in liquid communication with the waste liquid tank through a fourth flow channel and a fifth flow channel, as in Claim 4.
However, Applicant’s instant claimed fourth and fifth channels comprise a singular flow path, wherein said channels connect end-to-end (as seen through the instant filed drawings Fig. 2). Mere duplication of parts has no patentable significance unless a new and unexpected result is produced – see MPEP 2144.04(VI)(B). Herein, the two connected channels of the instant claimed invention and the singular flow channel of Lin commonly form a singular flow path connecting the detection area to the waste tank. By this, the prior art device would not function differently than the claimed device. Thus, one of ordinary skill in the art would find it obvious that the two claimed channels of the instant invention are equivalent to the one channel of Lin (See the annotated Fig. 3C above.).
Further, Ukita teaches a respective microfluidic chip wherein the flow path to the waste reservoir comprises two flow channels connected by a through hole to form a singular flow path (See the annotated Fig. 1 below.).
Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to modify the microfluidic chip taught by Lin with a fourth and fifth flow channel leading to the waste reservoir, such as taught by Ukita, so as to provide a sufficient structure to form a flow path to the waste reservoir.
Additionally regarding Claim 4, Lin does not specifically teach the first flow channel, the second flow channel and the fifth flow channel as located the first side of the substrate, and the third flow channel, the fourth flow channel and the detection flow channel as located on the second side of the substrate, as in Claim 4.
However, mere change in orientation or position of elements absent any criticality or unexpected result is an obvious matter of design choice – see MPEP 2144.04(VI)(C). Herein, the device having the claimed relative arrangement of parts would not perform differently than the prior art device, absent evidence of criticality, non-obviousness, or unexpected results associated with the positions of said flow channels.
By this, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it an obvious design choice to fabricate the microfluidic chip of Lin wherein the first flow channel, the second flow channel and the fifth flow channel are located on one side of the substrate, and the third flow channel, the fourth flow channel and the detection flow channel are located on the other side of the substrate (see also the 35 USC 112 section above).
Regarding Claim 8, the prior art meets the limitations of Claim 4 as discussed above. Further, Lin does not specifically teach the microfluidic chip discussed above wherein the first flow channel and the second flow channel are connected with the third flow channel via through holes, and the fourth flow channel is connected with the fifth flow channel through a through hole, as in Claim 8.
However, Ukita teaches a respective microfluidic chip wherein:
a first flow channel and a second flow channel are connected with a third flow channel via through holes (See the annotated Fig. 1 below.),
and a fourth flow channel is connected with a fifth flow channel through a through hole (See the annotated Fig. 1 below.).
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Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to modify the microfluidic chip of Lin with through holes for connecting the respective channels discussed so as to provide a suitable structure for forming a flow path between reagent storage tanks, a detection zone, and a waste reservoir, as similarly contemplated by Lin.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Lin in view of Ukita, as applied to Claims 4 and 8 above, and in further view of Rogers et al. (US 2018/0064377 A1), referred to hereinafter as “Rogers.”
Regarding Claim 6, the prior art meets the limitations of Claim 4 as discussed above. Further, Lin/Ukita does not specifically teach the microfluidic chip discussed above wherein the first flow channel, the second flow channel and the fifth flow channel are hydrophobic flow channels; and the third flow channel, the fourth flow channel and the detection flow channel are hydrophilic flow channels, as in Claim 6.
However, Rogers discloses a respective microfluidic device wherein the flow of a liquid sample is controlled by the respective hydrophobicity and hydrophilicity of the channels contained therein, discussed in further detail above regarding Claim 5.
Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious through routine engineering and design to modify the microfluidic chip taught by Lin with flow channels wherein the first flow channel, the second flow channel and the fifth flow channel are hydrophobic flow channels; and the third flow channel, the fourth flow channel and the detection flow channel are hydrophilic flow channels, such as suggested by Rogers teaching of flow channels having opposite hydrophilicity and hydrophobicity to control flow, so as to prevent flow through the first and second channels before a user intends to begin the assay (such as before the chip is spun by the centrifuge), to promote flow in the third and fourth channels to allow the sample to be wicked into and held in the detection area, and to prevent unintended flow through the fifth channel to the waste until detection is performed in the detection area, and would have a reasonable expectation of success in Lin.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Lin, as applied to Claims 1, 3 and 9-10 above, in view of Chen et al. (US 2013/0078711 A1), referred to hereinafter as “Chen.”
Regarding Claim 7, the prior art meets the limitations of Claim 1 as discussed above. Further, Lin does not specifically teach the microfluidic chip discussed above as further comprising an upper cover plate in contact with, and providing a water-tight cover over the first side of the substrate and a lower cover plate in contact with, and providing a water-tight cover over the second side of the substrate; wherein a portion of the upper cover plate in contact with the substrate is hydrophobic, a portion of the lower cover plate in contact with the substrate is hydrophilic, as in Claim 7.
However, Chen teaches a respective microfluidic device wherein a central channel-containing substrate layer 3 is flanked by an upper cover plate 2 and a lower cover plate 4 which provide a water-tight seal around the microfluidic channel/chamber layer. Further, the upper cover plate 2 is at least partially hydrophobic given that said upper cover plate 2 comprises hydrophobic regions 250; and the lower cover plate 4 is at least partially hydrophilic given that said lower cover plate 4 comprises hydrophilic regions 248 (Fig. 17a and [0061]: “…first layer 182 and a second layer 184 separated by a tape that includes multiple discs and apertures, including a hydrophilic disc and a hydrophobic disc…”) -- Further, said tape layers 2 and 4 provide a water-tight seal as discussed in para. [0100]: “double-sided and impermeable tape.” Chen describes the benefit of this arrangement as promoting the preferred directional wicking of the fluid sample ([0055]).
Thus, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to modify the microfluidic chip taught by Lin with an upper cover plate in contact with, and providing a water-tight cover over the first side of the substrate and a lower cover plate in contact with, and providing a water-tight cover over the second side of the substrate; wherein a portion of the upper cover plate in contact with the substrate is hydrophobic, a portion of the lower cover plate in contact with the substrate is hydrophilic, such as suggested by Chen, so as to provide a liquid-tight seal around the fluid-handling channels, and to promote the wicking of the fluid sample through the chip in the preferred and desired direction so as to enable the directional flow-dependent functionality of the chip.
Response to Arguments
35 USC 102
Applicant’s arguments are on the grounds that Lin does not teach or suggest a microfluidic chip wherein fluid flow does not rely on centrifugal force or air pressure force, as in Applicant’s amendments to Claim 1.
Applicant’s arguments are not persuasive because, as discussed above in the body of the action, the commensurate arrangement of channels and chambers of Lin as in the instant claims inherently provides for the limitations of being capable of use without centrifugal force and/or air pressure, given its commensurate arrangement as in the instant claims. Further, one may achieve the forces necessary in Lin for overcoming capillary constrictions through means other than centrifugal force or air pressure, such as by hand. This is further seen as the claims are drawn to a device and Applicant has failed to structurally distinguish the claimed device from that of the prior art of Lin.
Thus, Examiner respectfully maintains the rejection of Claims 1, 3, and 9-10 under 35 USC 102 as anticipated by Lin. Further note the 35 USC 112(a) section above discussing Applicant’s amendment requiring those negative limitations against centrifugal force and air pressure as being interpreted as new matter herein.
35 USC 103
Regarding Ukita, Applicant argues that the additional reference of Ukita does not cure the alleged deficiencies of Lin as in the amendments to Claim 1.
Applicant’s arguments are not persuasive because, as discussed above, no such deficiencies exist in Lin given its commensurate arrangement of channels and chambers, wherein one skilled in the art could manipulate the chip by hand to achieve a desired flow under force of gravity.
Regarding Ukita and Rogers, Applicant argues that the additional reference of Rogers is non-analogous to that of Lin and Ukita as Rogers does not rely on centrifugation, and that the rationale to modify Lin/Ukita so as to prevent unwanted flow and promote desired flow is allegedly a product of hindsight as Lin/Ukita rely on precise centrifugation speed control for controlling fluid flow.
Regarding Rogers as analogous to Lin/Ukita, Applicant’s argument is not persuasive because Rogers teaches use of the device with a centrifuge to cause flow from storage chambers to corresponding extraction chambers ([0173]). Further, even if Rogers did not utilize centrifugation, Rogers remains drawn to the field of microfluidics wherein merely causing flow through means not including centrifugation would not sway one skilled in the art away from recognizing the benefits of the specific microfluidic structures of Rogers wherein flow is merely caused by a separate force.
Regarding Applicant’s hindsight assertion, Applicant’s argument is not persuasive because Lin discusses the problem of precise sequential delivery of flow within the device for time-dependent processes and modification/tuning thereof ([0068-0069]: “delivery timings and sequence of the second test solution, the third test solution, and the fourth test solution”). Thus, one skilled in the art would recognize the hydrophobic/hydrophilic channels of Rogers as a solution for further controlling (additional to centrifugation speed) the precise sequential delivery of flow within the device for time-dependent processes within the device, and modification/tuning thereof, thereby reducing unwanted flow and promoting desired flow within the device.
Thus, Examiner respectfully maintains the rejection of Claim 6 under 35 USC 103 as unpatentable over Lin in view of Ukita and Rogers.
Regarding Ukita and Chen, Applicant argues that the additional reference of Chen is non-analogous to that of Lin and Ukita as Chan does not rely on centrifugation, and that the rationale to modify Lin/Ukita to provide a liquid-tight seal and promote the flow of fluid through the chip in a preferred direction is allegedly a product of hindsight as Lin/Ukita rely on precise centrifugation speed control for controlling fluid flow.
Regarding Chen as analogous to Lin/Ukita, Applicant’s argument is not persuasive because Chan discusses prospective use of centrifugation in para. [0065] for removing contaminating or obstructing material. Further, even if Chan did not utilize centrifugation, Chen remains drawn to the field of microfluidics wherein merely causing flow through means not including centrifugation would not sway one skilled in the art away from recognizing the benefits of the specific microfluidic structures of Chen wherein flow is merely caused by a separate force.
Regarding Applicant’s hindsight assertion, Applicant’s argument is not persuasive because Lin discusses the problem of precise sequential delivery of flow within the device for time-dependent processes and modification/tuning thereof ([0068-0069]: “delivery timings and sequence of the second test solution, the third test solution, and the fourth test solution”). Thus, one skilled in the art would recognize the hydrophobic/hydrophilic arrangement of Chen as a solution for further controlling (additional to centrifugation speed) the precise sequential delivery of flow within the device for time-dependent processes within the device, and modification/tuning thereof, thereby reducing unwanted flow and promoting desired flow within the device.
Conclusion
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/B.J.K./Examiner, Art Unit 1798
/NEIL N TURK/Primary Examiner, Art Unit 1798