Background

[0001] Digital microfluidic (DMF) devices enable manipulation of small droplets to facilitate handling and testing various liquid solution on a very small scale. Among other uses, DMF devices have begun to revolutionize field testing, mobile laboratory work, and the like.

Brief Description of the Drawings

[0002] FIG. 1 is a diagram including a side view schematically representing an example input/output interface device.

[0003] FIGS. 2 and 3 each are a diagram including a side view schematically representing an example input/output interface device including a sensor(s). [0004] FIG. 4 is a diagram including a side view schematically representing an example input/output interface device connected to an output port and an input port of a digital microfluidic (DMF) device.

[0005] FIG. 5A is a diagram including a series of side views schematically representing an example pump assembly.

[0006] Figure 5B is a block diagram schematically representing an array of valve types.

[0007] FIG. 6A is a diagram including a side view schematically representing an example input/output interface device including a series of pumps.

[0008] FIG. 6B is a diagram including a side view schematically representing an example input/output interface device connected to an output port of a DMF device.

[0009] FIGS. 7 and 8 are diagrams including a side view and a top view, respectively, schematically representing an example input/output interface device connected to an input port of a DMF device and including multiple conduit portions arranged to form droplets. [0010] FIG. 9 is a diagram including a top view schematically representing example droplet formation within an example input/output interface device. [0011] FIGS. 10 and 11 are diagrams including a side view and a top view, respectively, schematically representing an example input/output interface device connected to an input port of a DMF device and including multiple conduit portions arranged to form droplets.

[0012] FIG. 12 is a diagram including a top view schematically representing example droplet formation within an example input/output interface device. [0013] FIGS. 13 is a diagram including a top view schematically representing an example input/output interface device connected to an input port of a DMF device and including multiple conduit portions arranged to form droplets.

[0014] FIG. 14 is a diagram including a top view schematically representing example droplet formation within an example input/output interface device. [0015] FIG. 15A is a block diagram schematically representing an example operations engine.

[0016] FIG. 15B is a block diagram schematically representing an example control portion.

[0017] FIG. 15C is a block diagram schematically representing an example user interface.

[0018] FIG. 16 is a flow diagram schematically representing an example method of manufacturing.

Detailed Description

[0019] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense. It is to be understood that features of the various examples described herein may be combined, in part or whole, with each other, unless specifically noted otherwise.

[0020] At least some examples of the present disclosure are directed to an interface device for moving at least one liquid droplet of a sample liquid relative to a digital microfluidic (DMF) device, such as moving the at least one liquid droplet into and/or out of the DMF device. Accordingly, in some examples, the interface device may sometimes be referred to as an input/output interface device. In some examples, the sample liquid may comprise an aqueous solution including an analyte(s) of interest. It will be understood that in at least some examples, the sample liquid is carried within and through the conduit of the interface device via a carrier liquid, such as an inert liquid filler which may comprise an oil or other inert liquid. Accordingly, individual droplets of the sample liquid may be separate from each other, with the carrier liquid being interposed between, and/or generally surrounding, the different discrete droplets of the sample liquid. With this in mind, even if not mentioned expressly, it will be understood that movement of an at least one droplet of the sample liquid within and through a conduit of the interface device may generally be accompanied by, and/or supported via, similar movement of the carrier liquid unless otherwise noted.

[0021] In some examples, the interface device may comprise a housing defining a first conduit between an inlet and an outlet, wherein at least one of the inlet and the outlet is connectable to at least one port of a digital microfluidic device. A first pump is supported by the housing and coupled relative to the first conduit to move at least one liquid droplet through the conduit, on a one-way basis, from the inlet to the outlet.

[0022] In some examples, the interface device may be used to receive the sample liquid from an external source and direct the liquid, as at least one droplet, into a DMF device. In some examples, the interface device may be used to receive at least one droplet of the sample liquid from a DMF device and direct the at least one droplet to an external receiver. In some examples, the interface device may receive at least one droplet of the sample liquid from a DMF device and direct the at least one droplet back into the DMF device. In some examples, the interface device may perform sensing and/or other operations relative to the at least one droplet of the sample liquid as the at least one droplet is passing through the interface device.

[0023] In some examples, the first pump is constructed to be operable independent of properties (e.g. thermal) of the at least one liquid droplet, which stands in contrast to some pumps such as thermal pumps (e.g. thermal ink jet, etc.). Via such arrangements, the first pump permits more robust operation of the interface device for a wider variety of liquids. In some such examples, the first pump may comprise a piezoelectric-based pump.

[0024] In some examples, the first pump may comprise a pump assembly comprising a piezoelectric element coupled relative to a fluid chamber, with one way valves secured to opposite sides of the chamber to promote flow of the at least one liquid droplet in a single direction through the pump assembly and through the first conduit to which the pump assembly is connected (e.g. in fluid communication with).

[0025] In some examples, the conduit and the pump are sized and shaped to operate the interface device to maintain movement of the at least one droplet through the conduit. Stated differently, the conduit and the pump may sometimes be referred to as being operable on a non-storage basis, i.e. without storing the at least one liquid droplet within the conduit and the pump. Accordingly, the input/output interface device is distinguishable from devices, containers, and the like which may store liquids either before, or after, being present within a digital microfluidic (DMF) device.

[0026] Moreover, in some examples of the present disclosure, the pump may be paused to permit or enhance sensing a class (e.g. aqueous solution or filler) of a property of the at least one liquid droplet within the conduit. However, the period of time for which the pump may be paused is of a small, finite time period, which is temporary and not on a time scale corresponding to a time period associated with storage.

[0027] These examples, and additional examples, are described below in association with at least FIGS. 1A-16. [0028] FIG. 1A is a diagram schematically representing an example arrangement 20 including an example input/output interface device 30. As shown in FIG. 1 , the interface device 30 comprises a housing 32 defining a conduit 40, which includes an inlet 42A, intermediate portion 43, and an outlet 42B. The housing 32 supports a pump P1 , which is positioned along and exposed to the intermediate portion 43 of the conduit 40 in some examples. In some examples, the pump P1 is at least partially contained within housing 32.

[0029] As further shown in FIG. 1 A, in the example arrangement 20, the inlet 42A of the conduit 40 of the interface device 30 may be in fluid communication with an output 52 of an external source 50 to receive a sample liquid volume from the external source 50, wherein the sample liquid volume may comprise at least one sample liquid droplet or a liquid stream, depending on the type of external source 50 (e.g. DMF device, other). Meanwhile, the outlet 42B of the conduit 40 of the interface device 30 may be in fluid communication with an input 62 of an external receiver 60 to direct a liquid volume (e.g. at least one droplet) into the external receiver 60. In some examples, the at least one sample liquid droplet may comprise, and/or may sometimes be referred to as, a fluid packet, which comprises a finite number of separate droplets which may be moved together within and through the conduit of the housing of an interface device.

[0030] In some examples, the external source 50 may comprise a digital microfluidic (DMF) device (e.g. 220 in FIG. 4), such as further described later in association with at least FIGS. 4 and 6 with the output 52 of the external source 50 corresponding to at least one port (e.g. 236A in FIG. 4) of the DMF device 220. In some such examples, at least one sample liquid droplet is withdrawn from the DMF device via the first pump P1 for movement within and through the conduit 40 of interface device 30 and then directed via outlet 42B into the external receiver 60. The external receiver 60 may comprise a port (e.g. 236B in FIG. 4) of the DMF device or may comprise a non-integrated device, such as later described in FIG. 6.

[0031] In contrast, in some examples, the external source 50 may comprise a device from which the inlet 42A of the conduit 40 of the interface device 30 may receive a liquid volume. In some such examples, as further described later in association with at least FIGS. 7-14, the liquid volume may comprise a liquid stream or other liquid form which is not in a discrete form, such as droplets. However, the above-noted at least one sample liquid droplet to be moved within and through conduit 40 may comprise at least a portion of the liquid volume received from the external source 50. In some such examples, the external receiver 60 may comprise a port (e.g. 236B in FIG. 4) of the DMF device. In such examples, the external source 50 may comprise a device other than the DMF device acting as the external receiver 60.

[0032] In some examples, the first pump P1 may comprise a piezoelectric-based pump, such later shown in at least FIGS. 5A-5B. In some such examples, the piezoelectric-based pump may comprise a pump assembly comprising a piezoelectric element combined with a pair of one-way valves to promote one way directional flow through the pump and conduit to which the pump is in fluid communication, as further described in association with at least FIGS. 5A-14. [0033] In some examples and with general applicability to the various examples of the present disclosure, upon activation the first pump P1 withdraws liquid from external source 50 into inlet 42A of conduit 40 and moves the liquid volume within and through the conduit 40 for output, via outlet 42B, into the external receiver 60. In some such examples, the conduit 40 is sized, shaped, and oriented for moving fluid (e.g. a fluid droplet) within and through the conduit 40 without storing the fluid droplet. Stated differently, the conduit 40 may sometimes be referred to as a non-storage conduit or the interface device 30 may sometimes be referred to as a non-storage device, at least with regard to the fluid received from the external source 50. In a related aspect, in cooperation with the size, shape, and/or orientation of the conduit 40, in some examples the first pump P1 is sized, positioned, and controllable to move the fluid (e.g. droplet 45) within and through the conduit 40 without storing the fluid within the interface device 30. In some examples, the conduit 40 may comprise the sole conduit through which a liquid volume (e.g. at least one liquid droplet) of aqueous solution may be moved within and through the interface device 30.

[0034] However, it will be understood that the first pump P1 may be controlled in order to pause movement of liquid droplet(s) within and through the conduit 40 for a period of time sufficient to allow some operation (e.g. sensing) to performed relative to the liquid droplet(s). Upon completion of the pertinent operation, the pumping action is resumed to continue moving the at least one liquid droplet within and through the conduit 40 for passage, via outlet 42B, out of the interface device 30. In some examples, some operations (e.g. sensing/other) may be performed within a housing 32 of the interface device 30 without pausing the pumping action of pump P1 such that the liquid volume (e.g. liquid droplet) is continuously (or substantially continuously) moved into, moved through, and out of the conduit 40 of the interface device 30.

[0035] FIG. 1 A is a block diagram of an example control portion 70 which may direct operation of the interface device 30, including first pump P1 , to receive liquid into and/or direct liquid out of the interface device 30, among other operations described below. In some examples, the control portion 70 may comprise one example implementation of, and/or comprise at least some of substantially the same features and attributes as, the control portion 1000 in FIGS. 15A-15C. Accordingly, the control portion 70 may be supported by or within housing 32 of interface device 30 or may be in communication with the interface device 30, among other example implementations described in association with at least FIGS. 15A-15C.

[0036] FIG. 2 is a diagram schematically representing an example arrangement 80 including an example input/output interface device 90, which may comprise at least some of substantially the same features and attributes as input/output interface device 30 (FIG. 1A) except further comprising a first sensor S1. As shown in FIG. 2, in some examples the first sensor S1 may be positioned along, and exposed to, the conduit 40 upstream from first pump P1 such that the first sensor S1 is interposed (along the conduit 40) between the first pump P1 and the inlet 42A of the conduit 40. In some examples, first sensor S1 is to sense incoming liquid to determine which class of fluids the liquid volume (e.g. at least one droplet or liquid stream) belongs, which in turn may be used to control operation of the first pump P1 . For instance, the first sensor S1 may be used to determine (e.g. discriminate) whether the incoming liquid is an inert filler (e.g. oil) or is an aqueous solution which comprises analytes of interest within at least one sample liquid droplet. In some examples, the first sensor S1 may comprise a thermal sensor which may send a thermal pulse into the incoming liquid and measure the time for the pulse to propagate through the liquid, and measure a temperature some distance away (e.g. at the sensor) to thereby determine a thermal conductivity of the fluid. An inert liquid filler (e.g. oil) and aqueous solution (e.g. including an analyte) forming the at least one sample liquid droplet exhibit different thermal conductivity properties. Accordingly, when embodied as a thermal sensor, the first sensor S1 may determine whether the incoming liquid is an inert filler (e.g. oil) or an aqueous solution. In some examples, the sensed thermal information may be used to control at least some pump operations, such as (but not limited to) pausing the first pump P1 , maintaining pumping action of the first pump P1 , etc.

[0037] FIG. 3 is a diagram schematically representing an example arrangement 120 including an example input/output interface device 130, which may comprise at least some of substantially the same features and attributes as input/output interface device 30 of FIG. 1A, except further comprising a second sensor S2. As shown in FIG. 3, in some examples the second sensor S2 may be positioned along, and exposed to, the conduit 40 downstream from first pump P1 such that the second sensor S2 is interposed (along the conduit 40) between the first pump P1 and the outlet 42B of the conduit 40. In some examples, second sensor S2 is to sense selectable parameters of the at least one liquid droplet 45. Among many other possible examples, in some examples at least some example parameters which may be sensed (via second sensor S2) may comprise impedance sensing, electrochemical sensing, plasmonic sensing, chemically-sensitive field-effect transistor (ChemFET) sensing, and the like.

[0038] In some examples, a control portion (e.g. 70 in FIG. 1 B) may direct the sensed information to be communicated to an external source 50, an external receiver 60, a DMF device (e.g. 220 in FIG. 4), or other device.

[0039] In some examples, an example interface device may comprise both first sensor S1 and second sensor S2. The example arrangement 200 in FIG. 4 provides one example implementation in which an example input/output interface device 210 comprises both of the respective first and second sensors S1 , S2. It will be understood that either or both of the first and second sensors may comprise part of any one of the various examples described in association with at least FIGS. 4-14.

[0040] FIG. 4 is a diagram schematically representing an example arrangement 200 including an example input/output interface device 210, which may comprise at least some of substantially the same features and attributes as input/output interface devices of FIGS. 1 A-3, except further comprising an inlet and an outlet which are particularly arranged for fluid communication with a digital microfluidic (DMF) device 220. As shown in FIG. 4, the interface device 210 comprises a first leg 250A and a second leg 250B spaced apart from the first leg 250A. The first leg 250A defines an inlet portion 251 A of conduit 40 and comprises a structure for establishing mechanical connection with the DMF device 220 so that inlet portion 251 A of conduit 40 will be in fluid communication with first port 236A of the DMF device 220 and the inlet portion 251 A can received at least one liquid droplet from the DMF device 220.

[0041] The second leg 250B defines an outlet portion 251 B of the conduit 40 of interface device 210, and comprises a structure for establishing mechanical connection with the DMF device 220 so that outlet portion 251 B of conduit 40 may be in fluid communication with second port 236B of the DMF device 220 so that outlet portion 251 B can direct the at least one liquid droplet into the DMF device 220.

[0042] As further shown in FIG. 4, in some examples the DMF device 220 may comprise arrays 230A, 230B of electrodes 232 for moving a liquid droplet within and through selected portions of the DMF device 220 according to desired operations (e.g. moving, splitting, merging, sensing, etc.). In some such examples, the liquid droplet(s) are moved within and through the DMF device 220 via principles of electrowetting movement, such as but not limited to electrowetting-on-dielectric (EWOD) movement. As part of operation of DMF device 220, it may be desired to perform, via input/output interface device 210, a sensing operation (or other operation) on at least one sample liquid droplet in a location external to the DMF device 220 before, during, or after some microfluidic operations within the DMF device 220. [0043] As further shown in FIG. 4, in some examples at least some of the electrodes 232 within DMF device 220 may be in close proximity to inlet portion 251 A of conduit 40 of the interface device 210 such that, upon activating first pump P1 , at least one sample liquid droplet may be withdrawn, via first port 236A, from the DMF device 220.

[0044] As further shown in FIG. 4, in some examples at least some of the electrodes 232 within DMF device 220 (e.g. at array 230B) may be in close proximity to outlet portion 251 B of conduit 40 of the interface device 210 such that, via the preceding/ongoing activation of first pump P1 , the at least one sample liquid droplet within conduit 40 is directed, via second port 236B, to the DMF device 220.

[0045] Via example arrangement 200, because each of the inlet 251 A and the outlet 251 B of the interface device 210 are connected a respective (e.g. output port, and input port of the DMF device 220) the interface device 210 may sometimes be referred to as being integrated with the DMF device 220. In other words, in some examples, via such integration, the liquid volume (e.g. at least one liquid droplet) passing through interface device 210 may exclusively be received from, and sent to, the same DMF device 220. Accordingly, to the extent that one of the example interface devices of the present disclosure may receive liquid from an external source or direct liquid to an external receiver, either of which are not integrated relative to the DMF device 220, such external devices may sometimes be referred to as a non-integrated device.

[0046] FIG. 5A is a diagram including a series of side views schematically representing an example arrangement 300 comprising an example pump assembly 301 . At least some aspects of the pump assembly 301 (FIGS. 5A-5B) may comprise at least some of substantially the same features and attributes as, or may be an example implementation of, the pumps (e.g. P1 , P2, P3, etc.) described in association with at least FIGS. 1 -4 and 6-16.

[0047] As shown in FIG. 5A, in some examples the pump assembly 301 may comprise a piezoelectric element 302, a chamber 308, first valve 322 with inlet 320, and second valve 324 with outlet 328. In some examples, the piezoelectric element 302 may comprise a piezoelectric membrane 304 and a copper membrane 306. The piezoelectric element 302 is mounted on one side (e.g. top) of the chamber 308 so that the piezoelectric element 302 (and particularly copper membrane 306) will be exposed to a liquid volume within the chamber 308. As further described later, the piezoelectric element 302 acts as a diaphragm deflectable into a concave position (frame b) and a convex position (frame c). [0048] As further shown in FIG. 5A, one end 323A of the first valve 322 is secured to inlet 320 while an opposite second end 323B of the first valve 322 is secured to a first side 309A of the chamber 308. Meanwhile, one end 325B of second valve 324 is secured to opposite second side 309B of the chamber 308 while an opposite end 325A of the second valve 324 is secured to outlet 328. [0049] In general terms, this configuration defines a flow direction which proceeds from left to right along directional arrow F1 .

[0050] In some examples, each valve 322, 324 comprises a passive one-way valve, which sometimes may be referred to as a passive check valve. In some examples, each valve 322, 324 may comprise a fixed-geometry valve which comprises no moving parts to perform their valve functions. Stated differently, the size, shape, and/or orientation of the static walls of the structure (defining the valve) which generally define a cone comprise the sole parts of the fixed- geometry valve. As further described later in association with at least FIG. 5B, the valve 322, 324 may comprise a type of one-way valve other than a fixed- geometry valve (e.g. 342 in FIG. 5B).

[0051] In operation, upon activation of pump assembly 301 , as shown in frame b of FIG. 5A, the piezoelectric element 302 initially exhibits a concave position (relative to the interior of the chamber 308), which creates a negative pressure to draw any liquid within the cones (which define the fixed geometry valves 322, 324) into the chamber 308, and then, as shown in frame c of FIG. 5A, the piezoelectric element 302 exhibits a convex position (relative to the interior of the chamber 308) which pushes liquid within the chamber 308 back out into the respective cone-shaped valves 322, 324.

[0052] At least because the first cone-shaped valve 322 has a first end 323A which is substantially narrower than its second end 323B, and the second cone- shaped valve 324 has a first end 325A which is substantially wider than its second end 325B, more fluid tends to flow out of chamber 308 into the second cone- shaped valve 324 than into first cone-shaped valve 322 such that fluid generally moves out of inlet 320 and into outlet 328, thereby moving fluid along the general flow direction F1 .

[0053] FIG. 5B is a block diagram schematically representing example array 340 of different kinds of valves, which may be placed on opposite sides of the piezoelectric element 302 (FIG. 5A) in order to form a pump assembly 301 which can operate in substantially the same manner as described in association with FIG. 5A, at least to the extent the valves 322, 324 in array 340 provide a one way valve function or substantially one-way function. As shown in FIG. 5B, array 340 may comprise a fixed-geometry valve 342, with the cone-shaped valves 322, 324 in FIG. 5A providing one example implementation of such valves. In some examples, array 340 may comprise a check valve 344 such as but not limited to a reed valve 346 or a tesla valve 348. In a manner similar to that shown in FIG. 5A, the respective check valves 344 are arranged on opposite sides of the chamber 308 to ensure that any fluid entering the pump assembly 301 from the inlet 320 passes into and through chamber and out through outlet 328 without returning to/through inlet 320.

[0054] FIG. 6A is a diagram including a side view schematically representing an example arrangement 300 including an example input/output interface device 310. In some examples, the interface device 310 may comprise an example implementation of, or comprise at least some of substantially the same features and attributes as, any one of the various example of the present disclosure as described in association with at least FIGS. 1 -5B, except with the pump P2 comprising a series of spaced apart units 352A, 352B, 352C along the conduit 40 of the interface device 310 in which each respective unit comprises an actuator (e.g. A1 , A2, A3) and a membrane (M). While FIG. 6A depicts three such units, it will be understood that a fewer number or a greater number of units may be present in interface device 310. The units 352A, 352B, 352C of pump P2 may be spaced apart by a distance D1 , which is selected to enhance movement of a fluid droplet within and through conduit 40 via a peristaltic-type pumping action in which the units 352A, 352B, 352C of pump P2 are actuated in sequence to push a liquid volume (e.g. droplets) within and through conduit 40 with a series of “pushes” separated by distance (D1 ) and a selectable time interval. It will be understood that each unit 352A, 352B, 352C may operate according to at least some of substantially the same features and attributes as described in association with the chamber 308, piezoelectric element 302 (e.g. including or defining an actuator), etc. in FIGS. 5A-5C with the series of units 352A, 352B, 352c functioning together as a single pump (as represented by indicator P2 in FIG. 6A) to move at least one liquid droplet within and through the conduit 40.

[0055] While FIG. 6A shows a second sensor S2, it will be understood that in some examples, the second sensor S2 may be omitted. In some such examples, a first sensor S1 may be incorporated into the interface device 310 or the interface device 310 may omit both a first sensor S1 and a second sensor S2. In some examples, the interface device 310 may retain the second sensor S2, and additionally comprise a first sensor S1. Moreover, the interface device 310 (including a series of pumps P1 , P2, P3) may be deployed at least in the type of example arrangement shown in FIG. 4.

[0056] FIG. 6B is a diagram including a side view schematically representing an example arrangement 400 including an example input/output interface device 410. In some examples, the interface device 410 may comprise an example implementation of, or comprise at least some of substantially the same features and attributes as, any one of the various example of the present disclosure as described in association with at least FIGS. 1 -6A, except with outlet 42B of conduit 40 of the interface device 410 connectable to an external receiver 60, which is not part of a DMF device such as DMF device 220 in FIG. 4. As further shown in FIG. 6B, via this arrangement, an inlet 215A of the interface device 410 may receive a liquid volume (e.g. at least one droplet 45) from a DMF device (e.g. 220 in FIG. 4) and transport the liquid volume (e.g. at least one liquid droplet 45), via conduit 40 to the external receiver 60 for use in other devices without providing a return path to the DMF device (e.g. 220 in FIG. 4) from which the liquid volume (e.g. droplet 45) was withdrawn.

[0057] FIGS. 7-9 are diagrams schematically representing example arrangements 500, 560, 580 relating to, and including, various aspects of an example input/output interface device 510. In general terms, the input/output interface device 510 is to receive an incoming aqueous solution from an external source 50 to be transported via a conduit 540 into a DMF device (e.g. 220 in FIG. 4). In some such examples, the incoming aqueous solution may comprise a liquid stream or other liquid volume not in droplet form. Accordingly, the input/output interface device 510 may convert the incoming liquid stream (or other non-droplet form) into discrete volumes, such as separate droplets.

[0058] In some examples, the input/output interface device 510 may comprise an example implementation of, or comprise at least some of substantially the same features and attributes as, any one of the various examples of the present disclosure as described in association with at least FIGS. 1 -6B. As shown in at least FIG. 8, the input/output interface device 510 comprises an inlet 542A (of conduit 540) being connectable to an external source 50 to receive a liquid volume from the external source 50. As shown in FIGS. 7-8, an outlet 551 A of a conduit 540 of the interface device 510 is connected to (and in fluid communication with) a second port (e.g. 236B) of a DMF device (e.g. 220 in FIG. 4). Flowever, as shown in at least FIG. 8, the external source 50 does not form part of the DMF device 220 to which the outlet 551 A of the conduit is connected (FIG. 7) and hence the external source 50 may sometimes be referred to as a non-integrated device.

[0059] Accordingly, the example input/output interface device 510 receives a fluid from an external source 50 for transport into a DMF device.

[0060] As further shown in the side view of FIG. 7 and the top view of FIG. 8, the interface device 510 may comprise a first conduit portion 541 within housing 32, which has a first orientation (G1 ) to receive and transport the above-noted incoming liquid stream from the external source 50 within and through conduit 540. In some examples, the first conduit portion 541 may sometimes be referred to as a first fluid pathway. The input/output interface device 510 also may comprise a second conduit portion 570 within housing 32 to receive a stream of a liquid filler, with the second conduit portion 570 having a second orientation (G2) to intersect with the first conduit portion 541 at an intersection 557 (e.g. junction). In some examples, the second conduit portion 541 may sometimes be referred to as a second fluid pathway. The second orientation G2 is generally perpendicular to the first orientation G1 such that the intersection 557 may sometimes be referred to a T-shaped intersection, at least from the perspective of the incoming stream 862 of aqueous solution. From the intersection 557, the conduit 540 further comprises a third conduit portion 549 which extends from the intersection 557 of the first and second conduit portions 541 , 570 and proceeds to outlet 551 A to direct a pertinent liquid volume into the port 263B of a DMF device.

[0061] As further shown in FIGS. 7-8, the first conduit portion 541 may comprise a first pump P1 and supporting valves 322, 324 positioned to cause movement of the liquid volume (e.g. stream) from inlet 542A to the intersection 557 and through a third conduit portion 549 (e.g. main portion) of conduit 540. Meanwhile, the second conduit portion 570 may comprise a second pump P4 and supporting valves 322, 324 positioned to cause movement of the liquid filler from inlet 561 to the intersection 557 and through the third conduit portion 549 of conduit 540. [0062] As shown in FIGS. 7-9, via the first conduit portion 541 (including pump P1 and valves 322, 324), a regular flow (e.g. stream) of aqueous solution 582 flows into intersection 557 at which a regular flow of liquid filler (as represented by dashed arrow 562) from second conduit portion 570 (including pump P4 and valves 322, 324) is used to interrupt the stream of incoming aqueous solution (582) at regular time intervals to cause the formation of separate droplets 545 flowing within and through the third conduit portion 549, as shown in FIGS. 7-9. [0063] FIG. 9 provides a more detailed view of how the force of the incoming flow of liquid filler, as represented by dashed arrow 562, separates the incoming stream of aqueous solution (solid arrow 582) into separate, discrete droplets 545 with filler 533 interposed between and around the respective droplets 545, as also shown in FIGS. 7-8. In particular, as shown in FIG. 9, a partially formed droplet 584 extending from the fluid stream (solid arrow 582) is being formed due to the pressing, flow of the liquid filler (dashed arrow 562). After the inflow of a volume of incoming aqueous solution from external source 50 is completed and formed into droplets 545 within third conduit portion 549, then the pump P4 along second conduit portion 570 is deactivated to suspend inflow of the liquid filler. [0064] As further shown in FIGS. 7-8, upon separation of the incoming liquid stream (of aqueous solution) into discrete droplets 545, via the continued pumping action of pump P1 and/or pump P4, the third conduit portion 549 of conduit 540 directs the droplets to outlet 551 A for passage into port 236B of a DMF device 220. Once received within the DMF device (e.g. 220 in FIG. 4), the droplets may be moved, split, merged, sense, and otherwise manipulated to achieve the purposes and operations of the DMF device.

[0065] While not shown explicitly, it will be understood that the input/output interface device 510 may comprise the first sensor (S1 ) and/or the second sensor(s) (S2) along the conduit 540, in some examples.

[0066] FIGS. 10-12 are diagrams schematically representing example arrangements 700, 750, 780 relating to, and including, various aspects of an example input/output interface device 710. In a manner similar to the examples in FIGS. 7-9, and in general terms, the input/output interface device 710 of FIGS. 10-12 is to receive an incoming aqueous solution from an external source 50 to be transported via a conduit 740 into a DMF device (e.g. 220 in FIG. 4) with the input/output interface device 710 converting the incoming liquid volume (e.g. stream) into discrete liquid volumes, such as discrete, spaced apart droplets. Flowever, in the example arrangements in FIGS. 10-12, the interface device 710 employs a pair of interruptive streams (777A, 777B in FIGS. 11 -12) of liquid filler (e.g. oil) which flow parallel to the incoming stream (781 in FIGS. 11 -12) of aqueous solution, instead of a single stream of liquid filler (e.g. 562 in FIG. 9) flowing perpendicular to the incoming stream of aqueous fluid (e.g. 582 in FIG. 9) as in the example of FIGS. 7-9.

[0067] In some examples, the input/output interface device 710 of FIGS. 10-12 may comprise an example implementation of, or comprise at least some of substantially the same features and attributes as, any one of the various example of the present disclosure as described in association with at least FIGS. 1 -9. As shown in FIG. 10, the input/output interface device 710 comprises an inlet 742A (of conduit 740) being connectable to an external source 50 to receive the incoming stream of aqueous solution. An outlet 551 A of a conduit 740 of the interface device 710 is connected to (and in fluid communication with) the second port (e.g. 236B) of a DMF device (e.g. 220 in FIG. 4). In one aspect, the external source 50 is not part of the DMF device 220 to which the outlet 551 A of the conduit is connected. Accordingly, the input/output interface device 710 receives a fluid from an external source 50 for transport into a DMF device 220.

[0068] As further shown in the side view of FIG. 10 and the top view of FIG. 11 , the interface device 710 may comprise a first conduit portion 741 within housing 32, which has a first orientation (G1 ) to receive and transport the above-noted incoming fluid stream from the external source 50 within and through conduit 740. The first conduit portion 741 includes first pump P1 (and associate valves 322, 324). Meanwhile, the interface device 710 comprises additional second and third conduit portions 748A, 748B which also extend along (or parallel to) the second orientation (G2) with the second and third conduit portions 748A, 748B positioned alongside, and on opposite sides of, the first conduit portion 741 . Each of the second and third conduit portions 748A, 748B comprise a pump (e.g. P5, P6, respectively and associated valves 322, 324) as well as respective lateral portions 746A, 746B which serve as transitions to respective end portions 747A, 747B of the second and third conduit portions 748A, 748B.

[0069] As shown in the side view of FIG. 10 and the top view of FIG. 11 , per at least the pumping action of the first pump P1 , inlet 742A of first conduit portion 741 of input/output interface device 710 receives the incoming volume (e.g. stream of) of aqueous solution from external source 50 with the output flowing downstream from pump P1 within and through first conduit portion 741 to produce stream 781 within end portion 782 of first conduit portion 741 . Meanwhile, per at least the pumping action of pump P5, second conduit portion 748A receives an incoming flow of liquid filler material from filler source 55 with the output flowing downstream from pump P5 within and through second conduit portion 748A to form a first directed flow (dashed arrow 777A) of liquid filler parallel to, and immediately adjacent, the directed flow (solid arrow 781 ) of the aqueous solution from first conduit portion 741 . In a similar manner, per at least the pumping action of pump P6, the third conduit portion 748B receives an incoming flow of liquid filler material from a filler source 55 with the output flowing downstream from pump P6) within and through end portion 747A of third conduit portion 748B to form a second directed flow (dashed arrow 777B) of liquid filler parallel to, and immediately adjacent to, the directed flow (solid arrow 781 ) of the aqueous solution from first conduit portion 741 .

[0070] As further shown in FIGS. 11 -12, the second and third conduit portions 748A, 748B terminate within a common portion 749 of the conduit 740 at a point co-located with a termination of an outlet portion 782 of the first conduit portion 741 , such that the spaced apart, directed flows (dashed arrows 777A) of liquid filler and the more centrally located, directed flow (solid arrow 781 ) of aqueous solution all simultaneously enter the common portion 749 at a transition portion 739. As further shown in FIG. 12, at the transition portion 739 pressure from the directed flows (dashed arrows 777A, 777B) of liquid filler on opposite sides of the central flow (solid arrow 781 ) of aqueous solution causes separation of the flow of aqueous solution into discrete droplets 745 spaced apart (e.g. FIG. 10-11 ) from each other and flowing within and through common portion 749. In particular, as shown in FIG. 12, the pressure from the surrounding directed flows (dashed lines 777A, 777B) of liquid filler cause formation of a necked segment 782 of the aqueous solution with a partially formed droplet 783 extending from, and forming a terminal portion, of the directed flow (solid line 781 ) of the aqueous solution. With continued narrowing of the necked segment 782, the partially formed droplet 783 ultimately separates to become a discrete droplet 745 like the others shown in the common portion 749.

[0071] As further shown in FIGS. 10-11 , upon the separation of the incoming fluid stream of aqueous fluid into discrete droplets 745, via the ongoing pumping action of pumps P1 , P5, and/or P6, the common portion 749 of conduit directs the droplets 745, via outlet portion 551 A, into port 236B of a DMF device (e.g. 220 in FIG. 4). Once received within the DMF device (e.g. 220 in FIG. 4), the droplets 745 may be moved, split, merged, sense, and otherwise manipulated to achieve the purposes and operations of the DMF device.

[0072] FIGS. 13-14 are diagrams schematically representing example arrangements 800, 850 relating to, and including, various aspects of an example input/output interface device 810. In a manner similar to the examples in FIGS. 10-12, and in general terms, the input/output interface device 810 of FIGS. 13-14 is to receive an incoming aqueous solution from an external source to be transported via a conduit 840 into a DMF device (e.g. 220 in FIG. 4) with the input/output interface device 810 converting the incoming liquid volume/stream into discrete portions of liquid, such as individual, discrete droplets. Flowever, in the example arrangements in FIGS. 13-14, the interface device 810 employs a pair of interruptive streams 877A, 877B (dashed arrows) of liquid filler material which are oriented toward each other with both streams 877A, 877B being perpendicular to the directed flow 871 of incoming aqueous fluid.

[0073] In some examples, the interface device 810 may comprise an example implementation of, or comprise at least some of substantially the same features and attributes as, any one of the various example of the present disclosure as described in association with at least FIGS. 1 -12. In a manner similar to the example in FIGS. 10-12, and as shown in the top view of FIG. 13, the input/output interface device 810 comprises an inlet 742A (of conduit 740) being connectable to an external source 50. Like the example shown in FIGS. 10-11 , FIG. 13 shows that an outlet 551 A of the conduit 840 of the interface device 810 is provided for connection to (and in fluid communication with) the second port (e.g. 236B) of a DMF device (e.g. 220 in FIG. 4). Accordingly, the input/output interface device 810 receives a fluid from an external source for transport into a DMF device. [0074] As further shown in the top view of FIG. 13, the interface device 810 may comprise a first conduit portion 841 within housing 32 (like in FIGS. 10-12), which has a second orientation (G2) to receive and transport the above-noted incoming fluid stream from the external source 50 within and through conduit 840. Meanwhile, the interface device 810 comprises additional second and third conduit portions 848A, 848B which also extend in a first orientation (G1 ) with the second and third conduit portions 848A, 848B to be perpendicular to the first conduit portion 741. Except for their perpendicular orientation, each of the second and third conduit portions 848A, 848B are substantially similar to the second and third conduit portions 748A, 748B of the examples of FIGS. 10-12, with the second and third conduit portions 848A, 848B each comprising a respective pump assembly (e.g. P7, P8, respectively and associated valves 322, 324). As shown in FIGS. 13-14, an end of each respective second and third conduit portion 848A, 848B (including by their respective pump assemblies) join with end portion of first conduit portion 841 to form an intersection (e.g. junction) 857 at which the directed flows (871 , 877A, 877B) from each of the respective first, second, and third conduit portions 848A, 841 , 848B meet each other. Accordingly, the directed flows from each of the orthogonally-arranged, respective first, second, and third conduit portions 841 , 848A, 848B all simultaneously enter the intersection 857.

[0075] As shown in the top view of FIG. 13, per at least the pumping action of pump assembly (including pump P1 ), inlet 842A of first conduit portion 841 of input/output interface device 810 receives the incoming volume (e.g. stream of) of aqueous solution from external source 50 with the output flowing downstream to form directed flow 871 (solid arrow). Meanwhile, per at least the pumping action of pump P7, an inlet of second conduit portion 848A receives an incoming flow of liquid filler from filler source 55 with the output flowing within and through second conduit portion 848A to form a directed flow 877A of liquid filler, which is perpendicular to the directed flow 871 of the aqueous solution from first conduit portion 841 . In a similar manner, per at least the pumping action of pump P8, an inlet of third conduit portion 848B receives an incoming flow of liquid filler from filler source 55 with the output flowing downstream within and through third conduit portion 848B to form a second directed flow of liquid filler perpendicular to the directed flow of the aqueous solution from first conduit portion 741 .

[0076] FIG. 14 illustrates one example implementation of the interaction of these respective flows in intersection 857. As shown in FIG. 14, the pressure from the directed flows (dashed arrows 877A, 877B) of liquid filler effectively pinch the directed flow of aqueous solution exiting an end portion of the first conduit portion 841 to form a necked segment 856 of the aqueous solution, which with the aid of restriction portion 842 in conduit portion 841 , causes formation of droplets 845. FIG. 14 illustrates a partially formed droplet 853 at an end of the neck segment 856, downstream from the restriction portion 842, with partially formed droplet 853 about to break free to become a separated droplet 845. As noted elsewhere, while not shown in every instance, it will be understood that the liquid filler 533 generally surrounds the droplets 845 of aqueous solution within the pertinent portions of the conduit 840.

[0077] As further shown in FIG. 13, per the ongoing pumping action of the pump (e.g. P1 , P7, and/or P8, respectively) the droplets 845 flow through portion 849 of conduit 840 before exiting, via outlet portion 551 A, into port 236B of a DMF device (e.g. 220 in FIG. 4).

[0078] FIG. 15A is a block diagram schematically representing an example interface operations engine 900. In some examples, the interface operations engine 900 may form part of a control portion 1000, as later described in association with at least FIG. 15B, such as but not limited to comprising at least part of the instructions 1011. In some examples, the interface operations engine 900 may be used to implement at least some of the various example devices and/or example methods of the present disclosure as previously described in association with FIGS. 1A-14 and/or as later described in association with FIGS. 15B-16. In some examples, the interface operations engine 900 (FIG. 15A) and/or control portion 1000 (FIG. 15B) may form part of, and/or be in communication with, an input/output interface device or digital microfluidic (DMF) device, etc. such as the devices and methods described in association with at least FIGS. 1A-14 and 15C-16.

[0079] As shown in FIG. 15A, in some examples the interface operations engine 900 may comprise a sensing engine 910, a pumping engine 920, and a digital microfluidic engine 930. The sensing engine 910 may track and/or control sensing operations by an input/output interface device, and may do so per parameters relating to class 912 and/or type 914, or other parameters. Via the class parameter 912, the sensing engine may track and/or control sensing, such as via first sensor S1 (e.g. FIGS. 2, 4, 6B, etc.) to which class an incoming fluid droplet (or other volume) belongs, such as but not limited to whether the incoming fluid droplet is an aqueous solution or a filler (e.g. inert oil). Among other uses, such sensed information may be used to control pump operations such as activation, deactivation, speed, mode, etc. of a pump (e.g. P1 , etc.) of the input/output interface device. As previously noted, in some examples the first sensor S1 may comprise a thermal sensor to implement such sensing per class parameter 912.

[0080] Via the sensing type parameter 914, the sensing engine 910 may track and/or control sensing, such as via second sensor S2 (e.g. FIGS. 3, 4, 6A, etc.) of some examples of the present disclosure. Among other uses, the type of sensing performed may depend on or relate to the particular properties of an incoming fluid droplet (or other volume) to be sensed. In some such examples, the various types of sensing which may be tracked and/or controlled (per type parameter 914) may comprise impedance sensing, electrochemical sensing, plasmonic sensing, chemically-sensitive field-effect transistor (ChemFET) sensing, and the like. Via at least these types of sensing per type parameter 914, sensing engine 910 may sense chemical concentrations in a solution, such as a presence, absence, state, relative proportion, etc. of an analyte within a solution, such as (but not limited to) an aqueous solution. Among other uses, such sensed information may be communicated to a DMF device (e.g. 220 in FIG. 4), external source (e.g. 50), and/or external receiver (e.g. 60).

[0081] In some examples, in general terms the pumping engine 920 of the interface operations engine 900 is to track and/or control operation of a pump(s) (e.g. P1 , P2, etc.) of an input/output interface device. Such operations may comprise activation, deactivation, pause, timing, speed, mode, etc. of one or more pumps of an input/output interface device. Per an internal parameter 922, such pumping operations are tracked and/or controlled with respect to internal operations within the input/output interface device. Per an external parameter 924, the operation (e.g. activation, deactivation, pause, timing, speed, mode, etc.) of one or more pumps of an input/output interface device may be coordinated with fluid operations of a device external to the input/output interface device, such as a DMF device, external source, external receiver, etc. to which the input/output interface device is in fluid communication regarding a fluid volume (e.g. droplet, fluid stream, etc.).

[0082] The digital microfluidic (DMF) engine 930 is to coordinate operations of an example input/output interface device with control, by a digital microfluidic (DMF) device, of electrowetting-caused manipulation of droplets within such a DMF device, such as moving, merging, and/or splitting, respectively. Such manipulation may include causing droplets to move along a path within the DMF device to be withdrawn by, and/or received from, an example input/output interface device of the present disclosure.

[0083] It will be understood that various engines and parameters of operations engine 900 may be operated interdependently and/or in coordination with each other, in at least some examples.

[0084] FIG. 15B is a block diagram schematically representing an example control portion 1000. In some examples, control portion 1000 provides one example implementation of a control portion forming a part of, implementing, and/or generally managing the example microfluidic input/output interface devices, as well as the particular portions, components, pumps, sensors, digital microfluidic devices, operations, control portion, instructions, engines, functions, parameters, and/or methods, as described throughout examples of the present disclosure in association with FIGS. 1 -15A and 15C-16. In some examples, control portion 1000 includes a controller 1002 and a memory 1010. In general terms, controller 1002 of control portion 1000 comprises at least one processor 1004 and associated memories. The controller 1002 is electrically couplable to, and in communication with, memory 1010 to generate control signals to direct operation of at least some of the example microfluidic input/output interface devices, as well as the particular portions, components, pumps, sensors, digital microfluidic devices, operations, control portion, instructions, engines, functions, parameters, and/or methods, as described throughout examples of the present disclosure. In some examples, these generated control signals include, but are not limited to, employing instructions 1011 stored in memory 1010 to at least direct and manage microfluidic input/output operations via examples of the present disclosure. In some instances, the controller 1502 or control portion 1500 may sometimes be referred to as being programmed to perform the above- identified actions, functions, etc.

[0085] In response to or based upon commands received via a user interface (e.g. user interface 1020 in FIG. 15C) and/or via machine readable instructions, controller 1002 generates control signals as described above in accordance with at least some of the examples of the present disclosure. In some examples, controller 1002 is embodied in a general purpose computing device while in some examples, controller 1002 is incorporated into or associated with at least some of the example microfluidic input/output interface devices, as well as the particular portions, components, pumps, sensors, digital microfluidic devices, operations, control portion, instructions, engines, functions, parameters, and/or methods, etc. as described throughout examples of the present disclosure.

[0086] For purposes of this application, in reference to the controller 1002, the term “processor” shall mean a presently developed or future developed processor (or processing resources) that executes machine readable instructions contained in a memory or that includes circuitry to perform computations. In some examples, execution of the machine readable instructions, such as those provided via memory 1010 of control portion 1000 cause the processor to perform the above-identified actions, such as operating controller 1502 to implement input/output interface operations via the various example implementations as generally described in (or consistent with) at least some examples of the present disclosure. The machine readable instructions may be loaded in a random access memory (RAM) for execution by the processor from their stored location in a read only memory (ROM), a mass storage device, or some other persistent storage (e.g., non-transitory tangible medium or non-volatile tangible medium), as represented by memory 1010. The machine readable instructions may include a sequence of instructions, a processor-executable machine learning model, or the like. In some examples, memory 1010 comprises a computer readable tangible medium providing non-volatile storage of the machine readable instructions executable by a process of controller 1002. In some examples, the computer readable tangible medium may sometimes be referred to as, and/or comprise at least a portion of, a computer program product. In other examples, hard wired circuitry may be used in place of or in combination with machine readable instructions to implement the functions described. For example, controller 1002 may be embodied as part of at least one application-specific integrated circuit (ASIC), at least one field-programmable gate array (FPGA), and/or the like. In at least some examples, the controller 1002 is not limited to any specific combination of hardware circuitry and machine readable instructions, nor limited to any particular source for the machine readable instructions executed by the controller 1002.

[0087] In some examples, control portion 1000 may be entirely implemented within or by a stand-alone device.

[0088] In some examples, the control portion 1000 may be partially implemented in one of the example microfluidic input/output interface devices and partially implemented in a computing resource separate from, and independent of, the example microfluidic input/output interface devices but in communication with the example microfluidic input/output interface devices. For instance, in some examples control portion 1000 may be implemented via a server accessible via the cloud and/or other network pathways. In some examples, the control portion 1000 may be distributed or apportioned among multiple devices or resources such as among a server, an input/output interface device, digital microfluidic (DMF) device, a user interface, an external source, and/or an external receiver, etc.

[0089] In some examples, control portion 1000 includes, and/or is in communication with, a user interface 1020 as shown in FIG. 15C. In some examples, user interface 1020 comprises a user interface or other display that provides for the simultaneous display, activation, and/or operation of at least some of the example input/output interface devices, as well as the particular portions, components, pumps, sensors, digital microfluidic devices, operations, control portion, instructions, engines, functions, parameters, and/or methods, etc., as described in association with FIGS. 1 -15B and 16. In some examples, at least some portions or aspects of the user interface 1020 are provided via a graphical user interface (GUI), and may comprise a display 1024 and input 1022. [0090] FIG. 16 is a flow diagram of an example method 1100. In some examples, method 1100 may be performed via at least some of the devices, components, example input/output interface devices, as well as the particular portions, components, pumps, sensors, digital microfluidic devices, operations, control portions, engines, functions, parameters, and/or methods, etc. as previously described in association with at least FIGS. 1A-15C. In some examples, method 1600 may be performed via at least some devices, components, input/output interface devices, as well as the particular portions, components, pumps, sensors, digital microfluidic devices, operations, control portions, engines, functions, parameters, and/or methods, etc. other than those previously described in association with at least FIGS. 1 -15C.

[0091] As shown at 1112 in FIG. 16, in some examples method 1600 comprises forming a housing defining a conduit between an inlet and an outlet and to support a pump relative to the conduit to move at least one sample liquid droplet through the conduit from the inlet to the outlet. As further shown at 1114 in FIG. 16, in some examples method 1100 comprises at least one of: connecting the inlet to a first port of a DMF device and forming the outlet to direct the at least one sample liquid droplet to an external receiver; connecting the outlet to a second port of the DMF device and forming the inlet to receive a liquid volume, including the at least one sample liquid droplet, from an external source; and connecting the inlet to the first port of the DMF and connecting the outlet to the second port of the DMF device.

[0092] Although specific examples have been illustrated and described herein, a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein.