WO2023038630A1

WO2023038630A1 - Interface devices with electrodes for digital microfluidics

Info

Publication number: WO2023038630A1
Application number: PCT/US2021/049864
Authority: WO
Inventors: Viktor Shkolnikov; Michael W. Cumbie
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2021-09-10
Filing date: 2021-09-10
Publication date: 2023-03-16

Abstract

An interface device includes a housing that defines a microfluidic path including a conduit, wherein the microfluidic path is connectable to a first port of a digital microfluidic (DMF) device. A plurality of electrodes are supported by the housing and disposed proximal to the microfluidic path to move a sample fluid droplet into and through the microfluidic path.

Description

INTERFACE DEVICES WITH ELECTRODES FOR DIGITAL MICROFLUIDICS

Background

[0001] Digital microfluidic (DMF) devices may be used to perform operations on volumes of fluid, such as the manipulation of fluid droplets to facilitate handling and testing of various fluids on a small scale. Such devices may be used in the medical industry, for example to analyze deoxyribonucleic acid (DNA), detect pathogens, perform clinical diagnostic testing, and/or for synthetic chemistry, among other types of industries and/or for other purposes.

Brief Description of the Drawings

[0002] FIGs. 1 A-1 B illustrate example interface devices, in accordance with examples of the present disclosure.

[0003] FIGs. 2A-2H illustrate an example apparatus including a digital microfluidic (DMF) device and an interface device, in accordance with examples of the present disclosure.

[0004] FIGs. 3A-3F illustrate different example interface devices, in accordance with examples of the present disclosure.

[0005] FIG. 4 illustrates a three-dimensional view of an example apparatus including a DMF device and an interface device, in accordance with examples of the present disclosure.

[0006] FIG. 5 illustrates an example apparatus including a DMF device and a plurality of interface devices, in accordance with examples of the present disclosure.

[0007] FIG. 6 illustrates an example method for flowing a sample fluid droplet within an interface device, in accordance with examples of the present disclosure.

[0008] FIGs. 7-9 illustrate example arrangements that include an interface device including multiple conduit portions arranged to form fluid droplets, in accordance with examples of the present disclosure. Detailed Description

[0009] 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.

[0010] A digital microfluidic (DMF) device may have fluid input thereto and may perform operations thereon. DMF devices may be used to perform large numbers of chemical processing operations on different fluids, such as droplets, in parallel. As an example, a DMF device may be used for library preparation for sequencing, as well as sample preparation for immunoassays and nucleic acid tests. Materials, including a sample fluid, processed by the DMF device may be further processed by another microfluidic device. For example, for sequencing, the nucleic acid material processed with the library preparation material by a DMF device may be subsequently processed for sequencing. In order to perform the additional processing, such as for sequencing, the nucleic acid material may be removed from the DMF device and provided to another microfluidic device, such as via pipetting. Manual removal and transfer of the material may reduce efficiencies in performing the operations and increase risk for errors, such as due to contamination.

[0011] Examples of the present disclosure are directed to an interface device for moving a sample fluid droplet relative to a DMF device, such as moving at least one sample fluid droplet into and/or out of the DMF device. Accordingly, in some examples, the interface device may be referred to as an input/output interface device which provides an active interface for drawing fluid from and/or providing fluid to the DMF device. The interface device is itself a DMF device, which may be referred to as an accessory DMF device. In some examples, the sample fluid may comprise an aqueous solution including an analyte(s) of interest. In some examples, the sample fluid is carried within and through the conduit of the interface device via a carrier fluid. The carrier fluid may be an inert fluid filler, such an oil or other inert fluid. In other examples, the carrier fluid is another type of fluid, such as an aqueous fluid. Individual droplets of the sample fluid may be separate from each other, with the carrier fluid being interposed between, and/or generally surrounding, the different discrete droplets of the sample fluid. As described herein, in some examples and even if not mentioned expressly, the movement of the sample fluid droplet within and through a conduit of the interface device may be accompanied by, and/or supported via, similar movement of the carrier fluid unless otherwise noted.

[0012] In some examples, the interface device may comprise a housing that defines a microfluidic path including a conduit, wherein the microfluidic path is connectable to a first port of a DMF device. The interface device further includes a plurality of electrodes supported by the housing and disposed proximal to the microfluidic path to move a sample fluid droplet into and through the microfluidic path, such as through the conduit.

[0013] In some examples, the interface device may be used to receive the sample fluid droplet from an external source and direct the sample fluid droplet into a DMF device. In some examples, the interface device may be used to receive the sample fluid droplet from a DMF device and direct the sample fluid droplet to an external receiver. In some examples, the interface device may receive the sample fluid droplet from a DMF device and direct the sample fluid droplet back into the DMF device. In some examples, the interface device may perform sensing and/or other operations relative to the sample fluid droplet as the droplet is passing through the interface device.

[0014] The plurality of electrodes may be used to generate electrowetting forces on the sample fluid droplet to cause the movement of the sample fluid droplet. For example, the sample fluid droplet may be moved within and through the interface via principles of electrowetting movement, such as but not limited to electrowetting-on-dielectric (EWOD) movement. The plurality of electrodes provide an electric field within the conduit and/or onto the fluid, and due to a charge of the sample fluid droplet, the sample fluid droplet is directed along the microfluidic path. In some examples, the plurality of electrodes may be sequentially actuated to draw the sample fluid droplet along the microfluidic path. The plurality of electrodes and the conduit may be provided in different arrangements to provide a one-way path or a two-way path into and/or out of the interface device. The plurality of electrodes may be controlled by circuitry integrated with the housing or external circuitry. Driving fluid flow using the electrodes may provide instantaneous or near instantaneous response and may utilize existing control source.

[0015] Turning now to the figures, FIGs. 1A-1 B illustrate example interface devices, in accordance with examples of the present disclosure. The interface device 100, 101 is connectable to a DMF device, as further described herein. [0016] As shown in FIG. 1 A, an example interface device 100 comprises a housing 102 that defines a microfluidic path 115 including a conduit 104. In some examples, the conduit 104 includes a plurality of portions, such as an intermediate portion 111 -1 and at least one vertical portion 111 -2, 111 -3, as further illustrated by FIG. 1 B.

[0017] The housing 102 supports a plurality of electrodes 106-1 , 106-2 which are disposed proximal to the microfluidic path 115. In some examples, the electrodes 106-2, 106-2 are positioned along and exposed to the conduit 104. As further described herein, the plurality of electrodes 106-1 , 106-2 are to move a sample fluid droplet 112 into and through the microfluidic path 115. A fluid droplet, as used herein, refers to and/or includes a discrete portion of fluid (e.g., a liquid), which may be surrounded by another fluid. As an example of a fluid droplet, an immiscible fluid, such as an aqueous solution, is surrounded by an oil phase. As another example of a fluid droplet, an aqueous solution is surrounded by a gas, such as air. A sample fluid droplet includes a fluid droplet of a sample fluid. The sample fluid, as further defined below, includes a sample in a fluid or in a fluid form.

[0018] In some examples, the microfluidic path 115 includes a fluidic inlet 108 and/or a fluidic outlet 110. The fluidic inlet 108 and/or fluidic outlet 110 may include apertures which are connected to ports of the DMF device and/or other devices, such as other receivers or fluid sources. For example, the fluidic inlet 108 is connectable to an external source 105 and/or the fluidic outlet 110 is connectable to an external receiver 109. In some examples, the microfluidic path 115 includes the conduit 104 coupled between the fluidic inlet 108 and the fluidic outlet 110. However, examples are not so limited and, in some examples, the single aperture may be used as both a fluidic inlet and a fluidic outlet, as further illustrated by FIG. 3E.

[0019] In examples that include the fluidic inlet 108, the fluidic inlet 108 of the conduit 104 of the interface device 100 may be in fluid communication with an output 103 of an external source 105 to receive a fluid volume from the external source 105. For example, the fluid inlet 108 may be connected to the first port of the DMF device to draw fluid from the DMF device. In some examples, the fluidic inlet 108 may additionally or alternatively be used to direct fluid back to the DMF device. In other examples, the fluidic inlet 108 is connected to a port of another external source, which is external to both the interface device 100 and the DMF device,

[0020] The fluid volume may comprise the sample fluid droplet or a series of a plurality of sample fluid droplets. In some examples, the sample fluid droplet(s) may be carried by a carrier fluid. In some examples, the sample fluid droplet may comprise, and/or may 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 104 of the housing 102 of an interface device 100.

[0021] In examples that include the fluidic outlet 110, the fluidic outlet 110 of the conduit 104 of the interface device 100 may be in fluid communication with an input 107 of an external receiver 109 to direct a fluid volume (e.g., the sample fluid droplet or series of droplets) into the external receiver 109. For example, the fluidic outlet 1 10 may be connected the first port of the DMF device to direct fluid to the DMF device. In other examples, the fluidic outlet 110 is connected to a port of another external receiver, which is external to both the interface device 100 and the DMF device.

[0022] In some examples, the external source 105 may comprise a DMF device (e.g., 230 in FIG. 2A), such as further described in association with at least FIGs. 2A-2H with the output 103 of the external source 105 corresponding to a first port (e.g., 238-1 in FIG. 2A) of the DMF device. In some examples, the sample fluid droplet is withdrawn from the DMF device via the plurality of electrodes 106-1 , 106-2 for movement within and through the conduit 104 of the interface device 100 and then directed via fluidic outlet 1 10 into the external receiver 109. The external receiver 109 may comprise a port (e.g., 238-2 in FIG. 2A) of the DMF device or may comprise a non-integrated device, as further described herein.

[0023] In some examples, the external source 105 may comprise a device from which the fluidic inlet 108 of the conduit 104 of the interface device 100 may receive a fluid volume. In some such examples, as further described later in association with at least FIGs. 7-10, the external source 105 may convert the fluid volume, such as a liquid stream or other fluid form which is not in a discrete form, such as droplets, to the discrete form. In some such examples, the external receiver 109 may comprise a port of the DMF device. In some such examples, the external source 105 may comprise a device other than the DMF device acting as the external receiver 109.

[0024] In some examples, the plurality of electrodes 106-1 , 106-2 are disposed within the conduit 104. For example, as further illustrated by FIG. 1 B, the plurality of electrodes 106-1 , 106-2 may be disposed within the conduit 104 and proximal to the fluidic inlet 108 and/or the fluidic outlet 110. In some examples, at least a subset of the plurality of electrodes 106-1 , 106-2 may be disposed within at least one vertical portion of the conduit 104, and may be proximal to the fluidic inlet 108 and/or fluidic outlet 110.

[0025] The plurality of electrodes 106-1 , 106-2 may be actuated to provide electrowetting forces on fluids within or proximal to the microfluidic path 115 and to draw the fluids along the microfluidic path 115. For example, circuitry, such as circuitry 118 illustrated by FIG. 1 B, may be communicatively coupled to the plurality of electrodes 106-1 , 106-2 to actuate the plurality of electrodes 106-1 , 106-2 and, in response, cause application of electrowetting forces on the sample fluid droplet 112 and drive and/or draw flow of fluid including the sample fluid droplet 112 along the microfluidic path 115. In some examples, the circuitry is supported by the housing 102. However examples are not so limited, and the circuitry may take a variety of forms and/or be external to the housing 102.

[0026] In some examples, upon activation, the plurality of electrodes 106-1 , 106- 2 withdraw a fluid volume from the external source 105 into the fluidic inlet 108 of the conduit 104 and move the fluid volume within and through the conduit 104 for output, via fluidic outlet 1 10, into the external receiver 109. In some examples, the conduit 104 is sized, shaped, and oriented for moving fluid (e.g., a sample fluid droplet) within and through the conduit 104 without storing the fluid. Stated differently, the conduit 104 may be referred to as a non-storage conduit or the interface device 100 may be referred to as a non-storage device, at least with regard to the fluid received from the external source 105. In some examples, in cooperation with the size, shape, and/or orientation of the conduit 104, the plurality of electrodes 106-1 , 106-2 are sized, positioned, and controllable to move the fluid (e.g., sample fluid droplet 112) within and through the conduit 104 without storing the fluid within the interface device 100. In some examples, the conduit 104 may comprise the sole conduit through which a fluid volume may be moved within and through the interface device 100. In some examples, the conduit 104 may include or be coupled to an arrangement of chamber(s) and/or channel(s), among other features, such as sensors and actuators.

[0027] In some examples, the plurality of electrodes 106-1 , 106-2 may be controlled to pause movement of the sample fluid droplet 112 within and through the conduit 104 for a period of time sufficient to allow some operation (e.g., sensing) to be performed relative to the sample fluid droplet 112. Upon completion of the operation, the electric field (e.g., electrowetting) action is resumed to continue moving the sample fluid droplet 1 12 within and through the conduit 104 for passage, via the fluidic outlet 110, out of the interface device 100. In some examples, operations (e.g., sensing/other) may be performed within a housing 102 of the interface device 100 without pausing the activation of the electrodes 106-1 , 106-2, such that the fluid volume (e.g., sample fluid droplet 1 12) is continuously (or substantially continuously) moved into, moved through, and out of the conduit 104 of the interface device 100. [0028] FIG. 1 B illustrates another example interface device 101 which may comprise at least some of substantially the same features and attributes as interface device 100 of FIG. 1 A, with the addition of the circuitry 118 and sensor 120 supported by the housing 102. The common features and attributes are not repeated. The interface device 101 illustrates additional electrodes 106-1 , 106- 2, 106-3, 106-4, 106-5, 106-6, 106-7, 106-8, 106-9, 106-10, 106-N (herein generally referred to as “the electrodes 106” for ease of reference) as compared to the interface device 100; however, examples are not limited to the number of electrodes illustrated by the interfaces device 100, 101 and may include more or less electrodes.

[0029] The circuitry 1 18 may direct operation of the interface device 101 , including the plurality of electrodes 106, to receive fluid into and/or direct fluid out of the interface device 101 , among other operations described below. In some examples, the circuitry 118 is supported by or within the housing 102 of interface device 101 or may be in communication with the interface device 101 . [0030] As noted above, the conduit 104 may include a plurality of portions 1 1 1 - 1 , 1 1 1 -2, 1 1 1 -3. In some examples, the conduit 104 may include an intermediate portion 1 11 -1 and at least one vertical portion 1 11 -2, 111 -3. The intermediate portion 1 11 -1 may be coupled to the at least one vertical portion 1 11 -2, 1 11 -3. Although the intermediate portion 1 1 1 -1 is illustrated as a single horizontal channel, examples are not so limited and the intermediate portion 1 11 -1 may be in different arrangements, such as forming a chamber, a plurality of interconnected channels, and/or a plurality of chambers and interconnected channels, among other variations. The at least one vertical portion 1 11 -2, 1 1 1 -3 may form part of or be referred to as a leg which is used to connect to the DMF device or another external device, as further described below. Examples are not limited to two vertical portions 1 1 1-2, 1 1 1 -3, and may include more or less than illustrated by FIG. 1 B.

[0031] As described above, in some examples, the microfluidic path includes a fluidic inlet 108 coupled to conduit 104 and/or a fluidic outlet 110 coupled to the conduit 104. In the example illustrated by FIG. 1 B, the conduit 104 is coupled between the fluidic inlet 108 and the fluidic outlet 110, with the conduit 104 including a first vertical portion 111 -2, the intermediate portion 111 -1 , and a second vertical portion 111-3. In some examples, the fluidic inlet 108 is connectable to a first port of a DMF device and the fluidic outlet 110 is connectable to an external receiver. In other examples, the fluidic outlet 110 is connected to the first port of the DMF device and the fluidic inlet 108 is connectable to an external source. In some examples, the fluidic inlet 108 is connectable to a first port and the fluidic outlet 110 is connectable to a second port of the DMF device.

[0032] The plurality of electrodes 106 may be disposed within the microfluidic path in a variety of different arrangements and include different types and numbers of electrodes. In some examples, the plurality of electrodes 106 are disposed within the conduit 104, such as within the intermediate portion 111-1 and the at least one vertical portion 111 -2, 111 -2. For example, the plurality of electrodes 106 may include ring electrodes, linear electrodes, almost continuous electrodes, ground electrodes, and actuating electrodes, among others. The plurality of electrodes 106 may be the same size or different sizes. In some examples, the plurality of electrodes 106 or a portion thereof may include a plurality of ring electrodes disposed along the microfluidic path.

[0033] In some examples, a first subset of the plurality of electrodes 106 may be disposed along the first vertical portion 11 1-2 of the conduit 104, which are represented by the electrodes 106-1 , 106-2, 106-7, 106-8. A second subset of the plurality of electrodes 106 may be disposed along the second vertical portion 1 12-3 of the conduit 104, which are represented by the electrodes 106- 5, 106-10, 106-N. A third subset of the plurality of electrodes 106 may be disposed along the intermediate portions 11 1 -1 of the conduit 104, which are represented by the electrodes 106-3, 106-4, 106-9. In some examples, the first subset and second subset of electrodes, e.g., represented by 106-1 , 106-2, 106-7, 106-8 and 106-5, 106-10, 106-N respectively, may be ring electrodes which encircle the legs formed by the first and second vertical portions 111 -2, 112-3. In other examples, the first subset and second subset of electrode are linear electrodes. The third subset of electrodes may similarly be ring electrodes or linear electrodes. [0034] In some examples, the plurality of electrodes 106 include a first plurality of actuating electrodes and a second plurality of ground electrodes disposed along the microfluidic path. The circuitry 118 may select which respective electrodes are the actuating electrodes and ground electrodes. For example, portions of the first subset of the electrodes 106 disposed along the first vertical portion 1 11 -2, the second subset of the electrodes disposed along the second vertical portion 111 -3, and the third subset of electrodes disposed along the intermediate portion 111 -1 may be selected and/or used as ground electrodes, and the remaining portions may be used as actuating electrodes. As a specific example, electrodes on the outside of the conduit 104, e.g., 106-7, 106-8, 106- 9, 106-10, 106-N, may be used as ground electrodes, and electrodes on the inside of the conduit 104, e.g., 106-1 , 106-2, 106-3, 106-4, 106-5, may be used as actuating electrodes. In other examples, all electrodes are actuating, and no ground electrodes are used. In some examples, at different points in time, respective electrodes of the plurality 106 may be floating or set at ground, such as when the respective electrodes are not being used to draw the sample fluid droplet 1 12 along the microfluidic path.

[0035] As shown in FIG. 1 B, in some examples, the interface device 101 includes a sensor 120 supported by the housing 102. The sensor 120 may be positioned along, and exposed to, the conduit 104 downstream from at least a subset of the plurality of electrodes 106. Example sensors include, but are not limited to, an electrochemical sensor, a sensor to sense oxidation or reduction of oxidation, a resistance sensor, a capacitance sensor, an impedance sensor, a chemically-sensitive field-effect transistor (ChemFET) sensor, a plasmonic sensors, such as surface enhanced Raman spectroscopy (SERS) and surface plasmon resonance (SPR), among other types of sensors. The sensor 120 may be coupled to circuitry 118 and/or include communication circuitry to communicate to the circuitry 1 18.

[0036] The sensor 120 may determine a parameter of the sample fluid droplet 112. Example parameters which may be sensed include oxidation, impedance and/or other electrical properties, optical wavelengths and/or other properties, pH, temperature, electromagnetic fields, magnetic fields, among other types of parameters sensed through electrochemical sensing, plasmonic sensing, ChemFET sensing, among others.

[0037] In some examples, the sensor 120 is to sense incoming fluid to determine which class of fluids a fluid volume (e.g., includes a sample liquid droplet or not) belongs, which in turn may be used to control operation of the electrodes 106. For instance, the sensor 120 may be used to determine (e.g., discriminate) whether the incoming fluid is a carrier fluid (e.g., an inert filler fluid, such as oil) or is an aqueous solution which comprises analytes of interest within at least one sample fluid droplet. In some examples, the sensor 120 may comprise a thermal sensor which may send a thermal pulse into the incoming fluid and measure the time for the pulse to propagate through the fluid, and measure a temperature some distance away (e.g., at the sensor) to thereby determine a thermal conductivity of the fluid. An inert fluid filler (e.g., oil) and aqueous solution (e.g., including an analyte) forming the at least one sample fluid droplet exhibit different thermal conductivity properties. Accordingly, the sensor 120 may determine whether the incoming fluid is the inert fluid filler (e.g., oil) or an aqueous solution.

[0038] The circuitry 1 18 may track and/or control sensing operations by the interface device 101 , and may do so per parameters relating to class and/or type of sample and/or fluid, or other parameters. Using the parameter, the circuitry 118 may track and/or control sensing, such as via sensor signals from the sensor 120. As an example, the circuitry 119 may determine whether the incoming fluid droplet is an aqueous solution or an inert fluid, among other uses, and such sensed information may be used to control electrode operations such as actuating, setting to ground, or floating of an electrode of interface device. [0039] Examples are not so limited and the circuitry 118 may track and/or control sensing via the sensor 120 for other uses. Among example 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. Via the example types of sensing, the circuitry 1 18 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., 230 in FIG. 2A), an external source (e.g., 105 in FIG. 1A), and/or external receiver (e.g., 109 in Fig. 1A).

[0040] In some examples, the circuitry 118 may track and/or control operation of the plurality of electrodes 106 of the interface device 101. Such operations may comprise activation or actuation, deactivation, and other settings, such as setting to ground or floating and timings associated with the same. Such operations may be tracked and/or controlled with respect to internal operations within the interface device 101 . For example, the operation of an electrode of the interface device 101 may be coordinated with fluid operations of a device external to the interface device 101 , such as a DMF device, external source, external receiver, etc. to which the interface device is in fluid communication regarding a fluid volume (e.g., droplet, fluid stream, etc.).

[0041] The circuitry 118 may coordinate operations of the interface device 101 with control by the DMF device (e.g., 230 illustrated by FIG. 2A) or other external 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, the interface device 101 . [0042] The various examples operations of the circuitry 118 may be operated interdependently and/or in coordination with each other, in at least some examples.

[0043] FIGs. 2A-2H illustrate an example apparatus including a DMF device and an interface device, in accordance with examples of the present disclosure. The interface device 101 may include the interface device 101 of FIG. 1 B, with the fluidic inlet 108 and the fluidic outlet 110 being respectively coupled to a first port 238-1 and second port 238-2 of a DMF device 230.

[0044] The DMF device 230 may include a housing 234 that defines a conduit 232 and which provides a microfluidic path 239 for fluids. The first port 238-1 of the DMF device 230 may be in fluidic communication with the conduit 232 of the DMF device 230. The DMF device 230 may perform a variety of different operations on the fluid by driving the fluid along the microfluidic path 239. The DMF device 230 may further include a second (or more) port 238-2, as further described herein. In various examples, the DMF device 230 includes a lid and the first port 238-1 and/or second port 238-2 are disposed in and through the lid. [0045] In some examples, the DMF device 230 may comprise a plurality of electrodes 236 to move the sample fluid droplet 112 and other fluids within and through selected portions of the DMF device 230 according to target operations (e.g., moving, splitting, merging, sensing, etc.). In some examples, the sample fluid droplet 1 12 may be moved within and through the DMF device 230 via principles of electrowetting movement, as previously described. As part of operation of DMF device 230, via the interface device 101 , a sensing operation (or other operation) may be performed on the sample fluid droplet 112 in a location external to the DMF device 230 before, during, or after some microfluidic operations within the DMF device 230, as further described below. [0046] In some examples, the DMF device 230 may include a consumable microfluidic receptacle that includes the conduit 232 and the ports 238-1 , 238-2, and an electrode control element. The electrode control element includes the plurality of electrodes 236 supported on a substrate that are individually controllable, a chamber, and a plurality of apertures. The plurality of apertures extend through the substrate with the apertures being in communication with the chamber. A support may align the consumable microfluidic receptacle with the electrodes 236 to receive charges on an anisotropic conductivity portion of the receptacle to induce electrowetting movement of fluid droplet 1 12 within the conduit 232. Upon application of negative pressure through the chamber and the apertures, the electrodes 236 become releasably secured against the receptacle. Upon release of the negative pressure, the electrode control element may be released from the consumable microfluidic receptacle, and reused with another consumable microfluidic receptacle. Accordingly, the consumable microfluidic receptacle may be a single use microfluidic receptacle, such as disposable microfluidic receptacle.

[0047] In some examples, the control the flow of fluid within conduit 232 of the DMF device 230 may be provided via ion emitters of the consumable microfluidic receptacle, instead of and/or by the electrodes 236 of the electrode control element. In some examples, a charge applicator may be brought into charging relation to a plate of the consumable microfluidic receptacle, whereby the charge applicator is to apply (e.g., deposit) charges onto the plate to cause an electric field which induces electrowetting movement of a droplet within and through the consumable microfluidic receptacle. In some examples, the charge applicator is an addressable airborne charge depositing unit which may be brought into charging relation to the plate of the receptacle to deposit airborne charges onto the plate. In some examples, the charge applicator is the electrode control element which is brought into releasable contact with, and charging relation to, the plate. The charge applicator may generate and apply the charges having a first polarity and/or an opposite second polarity, depending on whether the charge applicator is to build charges on anisotropic conductivity portion of the consumable microfluidic receptacle or is to neutralize charges. The first polarity may be positive or negative depending on the particular goals, while the second polarity is the opposite of the first polarity. Via such example arrangements and in some examples, the consumable microfluidic receptacle may omit the electrodes 236, which would otherwise be used to cause microfluidic operations such as moving, merging, and/or splitting droplets within the DMF device 230. “Charges”, as used herein, refers to and/or ions (+/-) or free electrons.

[0048] As illustrated by FIG. 2A, the interface device 101 includes the housing 102 that defines a microfluidic path including the conduit 104 coupled to a fluidic inlet 108, and the plurality of electrodes, as previously described by FIG. 1 B. The fluidic inlet 108 is connected to the first port 238-1 of the DMF device 230. The microfluidic path of interface device 101 may further include a fluidic outlet 1 10 with the conduit 104 being coupled between the fluidic inlet 108 and the fluidic outlet 1 10. As described above, the fluidic inlet 108 may be connected to the first port 238-1 to withdraw fluid, including the sample fluid droplet 112, from the DMF device 230. In some examples, the fluidic outlet 110 is connected to the second port 238-2 of the DMF device 230 to direct the fluid to the DMF device 230. The plurality of electrodes are supported by the housing 102 and disposed proximal to the conduit 104 and the fluidic inlet 108 to move the sample fluid droplet 112 into the fluidic inlet 108 from the DMF device 230 and through the conduit 104. The electrodes, as represented by the labelled electrode 106, may be disposed within the conduit 104, and in some examples, may be exposed to fluid flowing through the conduit 104.

[0049] As shown by FIG. 2A, the interface device 101 may include a first leg 1 16-1 and a second leg 116-2 spaced apart from the first leg 1 16-1 . A leg, as used herein, refers to or includes a structure for establishing mechanical connection with another device. In some examples, the legs 1 16-1 ,1 16-2 may define portions of the conduit 104 and include tapered connectors for connecting to the other device, such as to ports in a lid of the other device. For example, the conduit 104 may include a first vertical portion 1 1 1 -2 defined by the first leg 116-1 , an intermediate portion 1 1 1 -1 , and a second vertical portion 1 1 1 -3 defined by the second leg 116-2. As previously described, the intermediate portion 1 11 -1 may include a main body with a chamber and/or a channel. The legs 116-1 ,1 16-2 may contain a subset of the plurality of electrodes. The housing 102 proximal to the first and second vertical portions 1 1 1 -2, 1 11 -3, which may form part of the legs 1 16-1 ,1 16-2, may define the fluidic inlet 108, the fluidic outlet 110, and the vertical portions 11 1 -2, 11 1 -3 of the conduit 104 of the microfluidic path.

[0050] For example, the first leg 1 16-1 defines the fluidic inlet 108 and comprises a structure to establish mechanical connection with the DMF device 230 so that the fluidic inlet 108 is in fluid communication with the first port 238-1 of the DMF device 230 and the fluidic inlet 108 may receive the sample fluid droplet 1 12 from the DMF device 230. The second leg 1 16-2 defines the fluidic outlet 1 10 of interface device 101 and comprises a structure to establish mechanical connection with the DMF device 230 so that fluidic outlet 110 is in fluid communication with the second port 238-2 of the DMF device 230 and the fluidic outlet 1 10 may direct the sample fluid droplet 112 into the DMF device 230.

[0051] The interface device 101 may further include circuitry 118 coupled to the plurality of electrodes, as previously described. In some examples, the circuitry 1 18 may sequentially actuate the plurality of electrodes, and in response to the sequential actuation, draw the sample fluid droplet 1 12 along the microfluidic path of the interface device 101 . An example operation of the apparatus 225 is further illustrated by FIGs. 2A-2H.

[0052] As shown by FIG. 2A, the interface device 101 may include a sensor 120, which may be disposed within the intermediate portion 11 1-1 of the conduit 104. In some examples, the sensor 120 is to sense selectable parameters of the sample fluid droplet 112. In other examples or in addition, the interface device 101 may include an actuator, which may be disposed within the intermediate portion 1 11 -1 of the conduit 104. The actuator may be used to mix fluids and/or other material, such as for mixing the sample fluid droplet 112 with other fluids and/or for collecting beads.

[0053] In some examples, the circuitry 118 may communicate the information sensed by the sensor 120 to other devices, such as an external source 105 of FIG. 1A, an external receiver 109 of FIG. 1A, and/or the DMF device 230, among or other devices. In some examples, the interface device 101 may comprise a plurality of sensors and/or actuators, among other features.

[0054] As further shown in FIG. 2A, in some examples, at least some of the electrodes of the interface device 101 may be disposed proximal to the fluidic inlet 108 of conduit 104 of the interface device 101 such that, upon actuating the at least some electrodes, the sample fluid droplet 1 12 may be withdrawn, via the first port 238-1 , from the DMF device 230. The electrodes may be disposed within the first leg 116-1 of the interface device 101 .

[0055] In some examples, at least some of the electrodes of the interface device 101 may be disposed proximal to fluidic outlet 110 of conduit 104 of the interface device 101 such that, upon actuating the at least some electrodes, the sample fluid droplet 112 is directed, via the second port 238-2, to the DMF device 230.

[0056] In some examples, because each of the fluidic inlet 108 and the fluidic outlet 110 of the interface device 101 are connected to a respective port 238-1 , 238-2 of the DMF device 230, the interface device 101 may be referred to as being integrated with the DMF device 230. In some examples, via the integration, a fluid volume passing through interface device 101 may be received from, and sent to, the same DMF device 230. In some examples, example interface devices of the present disclosure may receive fluid from an external source or direct liquid to an external receiver, either of which are not integrated relative to the DMF device 230, and such external devices may be referred to as a non-integrated device.

[0057] As previously described, the plurality of electrodes of the interface device 101 may have a variety of different arrangements and sizes. In some example, the electrodes of the interface device 101 are smaller, larger, and/or the same size as the plurality of electrodes 236 of the DMF device. The electrodes may be arranged in linear arrays, two dimensional (2D) arrays, and/or may include ring electrodes, and interface devices may include more or less electrodes than illustrated.

[0058] FIGs. 2A-2H illustrate an example operation of the apparatus 225 of FIG. 2A. Starting at FIG. 2A, the sample fluid droplet 112 may travel along the conduit 232 of the DMF device 230. The fluid flow may be provided by a variety of sources, such as via electrowetting, pumps, magnetic sources, and gravity, among other sources. Upon the sample fluid droplet 112 being proximal to the first port 238-1 , circuitry of the DMF device 230 provides a message to the circuitry 118 of the interface device 101 to actuate at least one electrode. For example, the interface device 101 actuates an electrode in the first leg 116-1 to draw the sample fluid droplet 112 into the fluidic inlet 108 and along the first vertical portion 111 -2 of the conduit 104 of the interface device 101 , as shown by FIG. 2B. The sample fluid droplet 112 may be pulled upward into the first leg 116-1 and against gravity.

[0059] As further illustrated herein by FIG. 3B, in some examples, the first and second legs 116-1 , 116-2 each respectively include a single electrode which respectively extend the length of the first and second legs 1 16-1 , 116-2. In other examples, the first and second legs 116-1 , 116-2 include subsets of electrodes. [0060] In some examples, a first subset of electrodes along the first vertical portion 1 11 -2 are sequentially actuated to draw the sample fluid droplet 112 into and along the first vertical portion 111-2 of the conduit 104, as shown by FIG. 2B and FIG. 2C. In other examples, the first vertical portion 111 -2 includes the single electrode that draws the sample fluid droplet 1 12 into the conduit 104 and/or each of the first subset of electrodes are actuated at the same time. [0061] In some examples, the intermediate portion 1 11 -1 (e.g., the body) includes a single linear array of electrodes along a side, and in other examples, includes a 2D array of electrodes along more than a side of the conduit 104. For example, a third subset of electrodes may be sequentially actuated, at the same time and/or sequentially to draw the sample fluid droplet 112 along the intermediate portion 111 -1 of the conduit 104, as shown by FIG. 2D and 2E. [0062] While the sample fluid droplet 112 is proximal to the sensor 120, the sensor 120 may detect properties of the sample fluid droplet 112. In some examples, the sensor 120 may protrude into the intermediate portion 111 -1 of the conduit 104 and the sample fluid droplet 112 may contact a surface of the sensor 120 to interact therewith. For example, the sensor 120 may pierce the sample fluid droplet 112 and sense a parameter of the droplet 112. However, examples are not so limited and other operations may be performed on the sample fluid droplet 112.

[0063] In some examples, the second subset of electrodes along the second vertical portion 111 -3 may be sequentially actuated to draw the sample fluid droplet 1 12 into and along the second vertical portion 111 -3 (e.g., along the second leg 116-2 of FIG. 2A), as shown by FIG. 2F and FIG. 2G. In other examples, the third vertical portion 111 -3 includes the single electrode that draws the sample fluid droplet 112 out of the conduit 104 through the fluidic outlet 110 and/or each of the second subset of electrodes are actuated at the same time.

[0064] The fluidic outlet 110, as shown by FIG. 2A, may be coupled to the second port 238-2 of the DMF device 230. As shown by FIG. 2H, the sample fluid droplet 112 may be directed back to the DMF device 230 and along the conduit 232 of the DMF device 230 via electrodes in the conduit 232 of the DMF device 230, as previously described.

[0065] In some examples, after the sample fluid droplet 112 is processed by the interface device 101 , a wash fluid may be passed through the conduit 104. The wash fluid may be provided as a fluid droplet or as another fluid volume. In some examples, the wash fluid may be input to the interface device 101 from the DMF device 230 and through the fluidic inlet 108. In other examples, the interface device 101 may include an additional fluidic inlet that is connected to an external source of wash fluid, and optionally, may include an additional fluidic outlet to provide the wash fluid to a waste receiver. After providing the wash fluid along the conduit 104 and while the waste fluid is being moved to another location, an additional sample fluid droplet may be provided at the fluidic inlet 108. In some examples, the sensor 120 and/or the interface device 101 may be a single use device and subsequent sample fluid droplets may be processed by a different part of the interface device 101 and/or another interface device coupled to the DMF device 230.

[0066] The interface device 101 and DMF device 230 may be formed of a variety of material formed in a stack. For example, the housings 102, 234 may formed of a plurality of different materials which are in layers, e.g., layers of substrates, in stack. The different material layers may include a first (transparent) substrate material (e.g., top) layer and a second substrate material (e.g., bottom) layer, with the conduit between. At least one of the substrate layers may have electrodes formed thereon. In some examples, the first (transparent) substrate material and the second substrate layer may have a low energy coating (e.g., Teflon, fluorosilane, Kapton FN, fluoroalkylsilane, 1 H, 1 H,2H,2H-Perfluorodecyltriethoxysilane, Trichloro( 1 H, 1 H,2H,2H- perfluorooctyl)silane)) proximal to and/or in contact with the conduit 104, 232 and the electrodes, and/or a dielectric coating (e.g., Kapton, ETFE, paralyne, alumina, silica, aluminum nitride, aluminum oxide) proximal and/or in contact with the electrodes and/or the low energy coating. The stack may additionally include a planarization layer that is a thickness that is proportional to the electrodes, which may be formed of SU-8, paralyne, PDMS, acrylates, among other materials. A carrier fluid (e.g., an inert filler fluid) may be filled in the conduits, such as an oil. The conduits may be a height in the range of 10 to 300 pm. The various electrodes may be a length of 40 pm to 3 mm.

[0067] Example interface devices and/or apparatuses device may include variations from that illustrated by FIGs. 1 B and 2A-2H. As noted above, such variations may include but are not limited to the connection of the interface device to the DMF or other devices, the number of fluidic inlets and/or outlets, the number of electrodes and/or arrangement of electrodes, among others. [0068] FIGs. 3A-3F illustrate different example interface devices, in accordance with examples of the present disclosure. Each of the example interface devices 350, 352, 358, 360, 362, 365 of FIGs. 3A-3F comprise an example implementation of, or comprise at least some of substantially the same features and attributes as, any one of the examples as described in association with at least FIGs. 1 A-2H, with example variations described herein. The details of the common features and attributes are not repeated for ease of reference.

[0069] As shown by FIG. 3A, in some examples, an interface device 350 may include at least one electrode that is an almost continuous electrode 351 . The almost continuous electrode 351 may be used as a ground electrode, with the remaining electrodes of the plurality being used as actuating electrodes.

[0070] In some examples, as shown by interface device 352 of FIG. 3B, a continuous electrode 353, 355 may be disposed within each of the two vertical portions 111 -2, 111 -3 of the conduit. The electrodes 353, 355 may be referred to as single leg electrodes. The example interface device 352 includes an almost continuous electrode 351 used as a ground electrode; however examples are not so limited. In some examples, the single leg electrodes 353, 355 and vertical portions 1 11-2, 111 -3 of the conduit 104 may be the same length as the length of the electrodes within the conduit 232 of the DMF device 230. However, examples are not so limited.

[0071] As shown by FIG. 3C, in some examples, an interface device 358 may include a continuous ground electrode 359 disposed along an inside of the intermediate portion 111 -1 of the conduit 104, with the remaining plurality of electrodes disposed on the outside of the conduit 104 along each of the intermediate portion 111 -1 and the vertical portions 11 1-2, 111 -3 being used as the actuating electrodes.

[0072] In some examples and as shown by FIG. 3D, an interface device 360 may include a continuous ground electrode 359 disposed along an inside of the intermediate portion 111 -1 of the conduit 104, with the remaining plurality of electrodes disposed on the outside of the intermediate portion 11 1-1 of the conduit 104 being used as actuating electrodes.

[0073] As shown by FIG. 3E and in various examples, the sample fluid droplet is pulled into and push out of an interface device 362 from the DMF device 230 via a fluidic inlet/outlet 364. In such examples, the microfluidic path through the conduit 104 is a two-way path. While examples are not so limited, the particular interface device 362 includes an almost continuous ground electrode 351 and a single leg electrode 353 along the vertical portion 111 of the conduit 104.

[0074] In other examples and as shown by FIG. 3F, an interface device 365 has a fluidic outlet 368 that connects to an external receiver that is not part of the DMF 230. The sample fluidic droplet may be flown from the DMF device 230 through conduit 104 of the interface device 365 to the external receiver through the fluidic outlet 368. Via this arrangement, a fluidic inlet 108 of the interface device 365 may receive a fluid volume (e.g., a fluid droplet) from a DMF device 230 and transport the fluid volume, via the conduit 104, to the external receiver for use in other devices without providing a return path to the DMF device 230 from which the fluid volume was withdrawn.

[0075] Although not illustrated, in some examples, the interface device 365 may be used with the fluidic outlet 368 operating as a fluidic inlet, where the sample fluid droplet is input to the conduit 104 of the interface device 365 from an external source that is not the DMF device 230 and flown to the DMF device 230. In some such examples, the interface device 365 may receive a fluid volume from the external source and transport the fluid volume, via the conduit 104, to the from a DMF device 230 without providing a return path to the external source from which the fluid volume was withdrawn.

[0076] Examples interface devices and apparatuses including an interface device and DMF device are not limited to the variations illustrated by FIGs. 3A- 3F. In various examples, the different variations and features illustrated by the devices 350, 352, 358, 360, 362, 365 may be combined in different combinations.

[0077] FIG. 4 illustrates a three-dimensional view of an example apparatus including a DMF device and an interface device, in accordance with examples of the present disclosure. The example apparatus comprises an example implementation of, or comprises at least some of substantially the same features and attributes as the apparatus 225 of FIG. 2A, but in a three- dimensional view 475. The common features and attributes are not repeated. In some examples, the vertical portions 111-2, 111 -3 of the conduit 104 may extend past the main portion of the housing 102, thereby forming leg portions 476-1 , 476-2 of the interface device 101 which may be connectable to the DMF device 230. The leg portions 476-1 , 476-2 may include or form the fluidic inlet 108 and/or fluidic outlet 110 which connect to the port(s) 238-1 , 238-2 of the DMF device 230. As previously described, in some examples, the conduit 104 may include ring electrodes which are disposed with the vertical portions of the conduit, as represented by the particular electrode 106.

[0078] FIG. 5 illustrates an example apparatus including a DMF device and a plurality of interface devices, in accordance with examples of the present disclosure. In some examples, the apparatus 580 includes a DMF device 582 including a plurality of portions, as represented by particular labelled portion 584. Each of the plurality of portions may include at least substantially the same features and attributes of the DMF device 230 described by FIG. 2A.

[0079] In some examples, a plurality of interface devices 586-1 , 586-2 may be connected to the DMF device 230. Each of the plurality of interface devices 586- 1 , 586-2 may include substantially the same features and attributes as described by any of the interface devices of FIGs. 1A-1 B, 2A, and 3A-3F. For example, each of the plurality of interface devices 586-1 , 586-2 include a housing defining a conduit and including at least one leg 588-1 , 588-2, 588-3, 588-4, 588-5, 588-6, 588-7, 588-8 and at least one sensor 120-1 , 120-2, 120-3. The legs 588-1 , 588-2, 588-3, 588-4, 588-5, 588-6, 588-7, 588-8 may include part of the conduit and/or may extend from the housing. Although FIG. 5 illustrates four legs per interface device 586-1 , 586-2, examples are not so limited and may include more or less legs. Additionally, the interface devices 586-1 , 586-2 may include more or less sensors, among other variations.

[0080] FIG. 6 illustrates an example method for flowing a sample fluid droplet within an interface device, in accordance with examples of the present disclosure. The method 690 may be implemented using any of the abovedescribed interface devices and apparatuses described above.

[0081] At 691 , the method 690 includes flowing a fluid including a sample fluid droplet along a first microfluidic path of a DMF device. At 693, the method 690 includes sequentially actuating a plurality of electrodes disposed proximal to a second microfluidic path of an interface device coupled to the DMF device. And, at 695, the method 690 includes, in response to the sequential actuating, drawing the sample fluid droplet into a fluidic inlet of the interface device via the actuation of an electrode of the plurality of electrodes disposed proximal to the fluidic inlet, and flowing the sample fluid droplet along the second microfluidic path of the interface device.

[0082] In some examples, sequentially actuating the plurality of electrodes includes introducing electrowetting forces on the fluid including the sample fluid droplet by actuating the electrode of the plurality of electrodes to draw the sample fluid into the fluidic inlet, the electrode being disposed proximal to the fluidic inlet, and sequentially actuating at least a subset of the remaining plurality of electrodes to move the sample fluid droplet along the second microfluidic path of the interface device. Actuating the electrode disposed proximal to the fluidic inlet may cause the sample fluid droplet to draw into the fluidic inlet and up a vertical portion of the conduit. That is, the electrowetting forces may be greater than gravitation forces acting on the sample fluid droplet. [0083] As described and illustrated herein, the second microfluidic path of the interface device may include a conduit formed in a housing of the interface device, the conduit being connected to the fluidic inlet. In some examples, the housing may further support a sensor. In some examples, the method 690 may further includes determining a parameter of the sample fluid droplet using the sensor supported by the housing and disposed with the conduit.

[0084] In some examples, other methods may be directed to forming or manufacturing an interface device and/or an apparatus as described herein. An example method of manufacturing may include forming a housing defining a microfluidic path including a conduit coupled to a fluidic inlet and to support a plurality of electrodes disposed along the microfluidic path to move a sample fluid droplet through the conduit and disposing the plurality of electrodes along the microfluidic path. In some examples, the method may further include connecting the microfluidic path (e.g., the inlet or outlet) to a first port of a DMF device. In some examples, the method may further include including positioning circuitry and/or a sensor along the conduit for support by the housing to expose the sensor to the conduit for determining a parameter of the sample fluid droplet and actuating the plurality of electrodes.

[0085] FIGs. 7-9 illustrate example arrangements that include an interface device including multiple conduit portions arranged to form fluid droplets, in accordance with examples of the present disclosure. The interface device 710 is to receive an aqueous solution from an external source 752 to be transported via a conduit 740 into a DMF device (e.g., 230 in FIG. 2A) or into another interface device (e.g., 101 in FIG. 2A). In some examples, the incoming aqueous solution may comprise a fluid stream or other fluid volume not in droplet form. The interface device 710 may convert the incoming fluid stream into discrete volumes, such as separate droplets. In some examples, the interface device 710 may be the external source 105 illustrated by FIG. 1A. [0086] In some examples, the interface device 710 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 as described in association with at least FIGs. 1 A-5, but with pumps P1 , P2 being located within the conduit 740 instead of or in addition to electrodes. As shown in at least FIG. 8, the interface device 710 comprises a fluidic inlet 742A (of conduit 740) being connectable to an external source 752 to receive a fluid volume from the external source 752. As shown in FIGs. 7-8, a fluidic outlet 751 A of a conduit 740 of the interface device 710 is connected to (and in fluid communication with) a port 738 of another device, such as a second port (e.g., 238-2) of a DMF device (e.g., 230 in FIG. 2A) or a fluidic inlet of another interface device (e.g., 368 of FIG. 3F). In some examples, as shown in at least FIG. 8, the external source 752 does not form part of the DMF device and/or the other interface device to which the outlet 751 A is connected (FIG. 7) and the external source 752 may sometimes be referred to as a non-integrated device. [0087] Accordingly, the example interface device 710 receives a fluid from an external source 752 for transport into a DMF device or into another interface device.

[0088] In some examples, the pumps P1 , P2 may comprise a piezoelectricbased pump. A piezoelectric-based pump may include 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. In some examples, the pumps P1 , P2 include thermal inkjet (Tl J) resistors. Activation of the TIJ resistor may create the flow of fluid by firing drops of fluid from the conduit 740 and/or creating a vapor bubble. [0089] As shown in the side view of FIG. 7 and the top view of FIG. 8, the interface device 710 may comprise a first conduit portion 741 within the housing 732, which has a first orientation (G1 ) to receive and transport the above-noted incoming fluid stream from the external source 752 within and through conduit 740. In some examples, the first conduit portion 741 may be referred to as a first microfluidic pathway. The interface device 710 also may comprise a second conduit portion 770 within the housing 732 to receive a stream of a carrier fluid 733 from a second source 755, with the second conduit portion 770 having a second orientation (G2) to intersect with the first conduit portion 741 at an intersection 757 (e.g., junction). The second source 755 may be internal or external to the interface device 710. In some examples, the second conduit portion 741 may be referred to as a second microfluidic pathway. The second orientation G2 is generally perpendicular to the first orientation G1 such that the intersection 757 may be referred to a T-shaped intersection, at least from the perspective of the incoming stream 782 of aqueous solution. From the intersection 757, the conduit 740 further comprises a third conduit portion 749 which extends from the intersection 757 of the first and second conduit portions 741 , 770 and proceeds to outlet 751 A to direct a pertinent fluid volume into the port 738 of the other device, such as the DMF device.

[0090] As shown in FIGs. 7-8, the first conduit portion 741 may comprise a first pump P1 and supporting valves 722, 724 positioned to cause movement of the fluid volume (e.g., stream) from inlet 742A to the intersection 757 and through a third conduit portion 749 (e.g., main portion) of conduit 740. The second conduit portion 770 may comprise a second pump P2 and supporting valves 722, 724 positioned to cause movement of the carrier fluid 733 from inlet 761 to the intersection 757 and through the third conduit portion 749 of conduit 740.

[0091] As shown in FIGs. 7-9, via the first conduit portion 741 (including pump P1 and valves 722, 724), a regular flow (e.g., stream 782) of aqueous solution flows into the intersection 757 at which a regular flow of carrier fluid (as represented by dashed arrow 762) from the second conduit portion 770 (including pump P2 and valves 722, 724) is used to interrupt the stream (782) of incoming aqueous solution at regular time intervals to cause the formation of separate droplets 112 flowing within and through the third conduit portion 749, as shown in FIGs. 7-9.

[0092] FIG. 9 provides a more detailed view of how the force of the incoming flow of carrier fluid, as represented by dashed arrow 762, separates the incoming stream of aqueous solution (solid arrow 782) into separate, discrete droplets 112 with carrier fluid 733 interposed between and around the respective droplets 112, as also shown in FIGs. 7-8. In particular, as shown in FIG. 9, a partially formed droplet 784 extending from the fluid stream (solid arrow 782) is being formed due to the pressing, flow of the carrier fluid (dashed arrow 762). After the inflow of a volume of incoming aqueous solution from external source 752 is completed and formed into droplets 112 within the third conduit portion 749, then the pump P2 along the second conduit portion 770 is deactivated to suspend inflow of the carrier fluid.

[0093] As further shown in FIGs. 7-8, upon separation of the incoming fluid stream (of aqueous solution) into discrete droplets 112, via the continued pumping action of pump P1 and/or pump P2, the third conduit portion 749 of conduit 740 directs the droplets 112 to outlet 751 A for passage into the port 738 of the other device. Once received within the DMF device (e.g., 230 in FIG. 2A) or the other interface device (e.g., 101 in FIG. 2A) the droplets 112 may be moved, split, merged, sense, and otherwise manipulated to achieve the purposes and operations of the DMF device or other interface device. [0094] Examples are not limited to the particular schematic of the interface device 710 used to generate sample fluid droplets. In some examples, the DMF device may generate the fluid droplets. In other examples, the interface device 710 may include variations, such as additional pumps, additional sources of carrier fluid, additional sensors, among other various. In some examples, the interface device 710 may employ a pair of interruptive streams of carrier fluid which flow parallel to the incoming stream of aqueous solution, instead of a single stream of carrier fluid flowing perpendicular to the incoming stream of aqueous fluid (e.g., 782 in FIG. 9) as in the example of FIGs. 7-9. In some examples, the interface device 710 comprises additional second and third conduit portions which also extend along (or parallel to) the second orientation (G2) with the second and third conduit portions positioned alongside, and on opposite sides of, the first conduit portion 741 . Each of the second and third conduit portions comprise a pump (e.g., similar to P1 and associated valves 722, 724) as well as respective lateral portions which serve as transitions to respective end portions of the second and third conduit portions.

[0095] As another example variation, the interface device 710 may employ a pair of interruptive streams of carrier fluid which are oriented toward each other with the streams being perpendicular to the flow of incoming aqueous fluid.

[0096] In some examples, an interface device 100 of FIG. 1 A or interface device 101 of FIG.1 B may be used in addition to or alternatively to the interface device 710 of FIGs. 7-9 to generate fluid droplets. For example and referring back to FIGs. 1A-1 B, the electrowetting forces generated by the electrodes 106-1 , 106-2 of the interface device 100 or the plurality of electrodes 106 of the interface device 101 may be used to split a fluid droplet into smaller fluid droplets. For example, using interface device 101 of FIG. 1 B as an example, at least two of the electrodes 106 may provide electrowetting forces on the fluid droplet 112 and split the fluid droplet 112 into at least two fluid droplets that are smaller than the fluid droplet 1 12. As another example, the interface device 101 may include a first electrode next to a second electrode, where the first electrode is larger than the second electrode (e.g., electrode 106-3 in FIG. 1 B and an electrode in the leg), which may be used to pull off a smaller droplet from the fluid droplet 112 using electrowetting forces. The fluid droplet 1 12 may be input to the interface devices 100, 101 by the interface device 710 of FIGs. 7-9 or by the DMF device (e.g., 230 of FIG. 2A).

[0097] As used herein, circuitry, such as the circuitry 118 of the interface device 101 of FIG. 1 B and/or the circuitry of the DMF device 230, may include a processor and a memory. In general terms, circuitry comprises a processor and associated memories, and may comprise communication circuitry. The circuitry may include a processor that is electrically couplable to, and in communication with, memory to generate control signals to direct operation of example interface devices and/or DMF devices, as well as the particular portions, components, electrodes, sensors, operations, instructions, parameters, and/or methods, as described herein. In some examples, the control signals include, but are not limited to, employing instructions stored in memory to at least direct and manage microfluidic operations. The circuitry may sometimes be referred to as being programmed to perform the above-identified actions, functions, etc.

[0098] In response to or based upon commands received and/or via machine readable instructions, the circuitry generates control signals as described above. In some examples, circuitry may be embodied in a general purpose computing device, while in some examples, circuitry may be incorporated into or associated with at least some of the example interface devices, as well as the particular portions, components, electrodes, sensors, DMF device, operations, instructions, parameters, and/or methods, etc. as described herein.

[0099] The term “processor” includes and/or refers to 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 of the circuitry cause the processor to perform the above-identified actions, such as circuitry to implement interface operations via the various example implementations. 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. The machine readable instructions may include a sequence of instructions, a processor-executable machine learning model, or the like. In some examples, memory comprises a computer readable tangible medium providing non-volatile storage of the machine readable instructions executable by a processor of circuitry. In some examples, the machine readable tangible medium may 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, circuitry 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 some examples, the circuitry 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 circuitry.

[00100] In some examples, the circuitry may be implemented within or by a stand-alone device, such as a microprocessor. In some examples, the circuitry may be partially implemented in interface devices and partially implemented in a computing resource separate from, and independent of, the example interface devices but in communication with the example interface devices. For instance, the circuitry may be implemented via a server accessible via the cloud and/or other network pathways. In some examples, the circuitry may be distributed or apportioned among multiple devices or resources

[00101] A sample and/or fluid sample as used herein, refers to and/or any material, collected from a subject, such as biologic material. Example samples include, but are not limited to, whole blood, blood plasma, and other body fluids, as well as tissue cell cultures obtained from humans, plants, or animals. Such samples may contain any viral or cellular material, including all prokaryotic or eukaryotic cells, viruses, bacteriophages, mycoplasmas, protoplasts, and organelles. Such biological material may comprise all types of mammalian and non-mammalian animal cells, plant cells, algae including blue-green algae, fungi, bacteria, protozoa, etc. Non-limiting examples of samples include whole blood and blood-derived products such as plasma, serum and buffy coat, urine, feces, cerebrospinal fluid or any other body fluids, tissues, cell cultures, cell suspensions, etc. Other example samples include fluids containing functionalized beads to which a portion of a biologic sample or other particles are attached

[00102] 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.

Claims

1 . An interface device comprising: a housing that defines a microfluidic path including a conduit, wherein the microfluidic path is connectable to a first port of a digital microfluidic (DMF) device; and a plurality of electrodes supported by the housing and disposed proximal to the microfluidic path to move a sample fluid droplet into and through the microfluidic path.

2. The interface device of claim 1 , wherein the microfluidic path further includes a fluidic inlet coupled to the conduit and the conduit includes at least one vertical portion, the fluidic inlet being proximal to a vertical portion and connectable to the first port of the DMF device to withdraw fluid from the DMF device, wherein the plurality of electrodes are disposed within the conduit including the vertical portion.

3. The interface device of claim 2, wherein the microfluidic path further includes a fluidic outlet connectable to an external receiver.

4. The interface device of claim 1 , wherein the microfluidic path further includes a fluidic outlet coupled to the conduit, the fluidic outlet being connectable to the first port of the DMF device to direct fluid to the DMF device, wherein the plurality of electrodes are disposed within the conduit and proximal to the fluidic outlet.

5. The interface device of claim 1 , wherein the microfluidic path includes the conduit coupled between a fluidic inlet and a fluidic outlet, the fluidic inlet being connectable to the first port of the DMF device and the fluidic outlet being connectable to a second port of the DMF device, wherein the plurality of electrodes are disposed within the conduit, the fluidic inlet, and the fluidic outlet.

6. The interface device of claim 1 , wherein the plurality of electrodes include a plurality of ring electrodes disposed along the microfluidic path.

7. The interface device of claim 1 , wherein the plurality of electrodes include a first plurality of actuating electrodes and a second plurality of ground electrodes disposed along the microfluidic path.

8. The interface device of claim 1 , further including a sensor supported by the housing and exposed to the conduit downstream from a subset of the plurality of electrodes to determine a parameter of the sample fluid droplet.

9. The interface device of claim 1 , further including circuitry supported by the housing and communicatively coupled to the plurality of electrodes to actuate the plurality of electrodes and, in response, cause application of electrowetting forces on the sample fluid droplet and drive flow of fluid including the sample fluid droplet along the microfluidic path.

10. An apparatus comprising: a digital microfluidic (DMF) device including a first port; and an interface device including: a housing that defines a microfluidic path including a conduit coupled to a fluidic inlet, wherein the fluidic inlet is connected to the first port of the DMF device; and a plurality of electrodes supported by the housing and disposed proximal to the conduit and the fluidic inlet to move a sample fluid droplet into the fluidic inlet from the DMF device and through the conduit.

11 . The apparatus of claim 10, wherein: the fluidic inlet is connected to the first port to withdraw fluid, including the sample fluid droplet, from the DMF device; and the m icrof luidic path further includes a fluidic outlet, wherein the conduit is coupled between the fluidic inlet and the fluidic outlet, and at least one of: the fluidic outlet is connected to a second port of the DMF device to direct the fluid to the DMF device; and the fluidic outlet is connectable to an external receiver; and the DMF device includes a lid, the first port and second port being disposed in the lid.

12. The apparatus of claim 10, wherein the plurality of electrodes are disposed within the conduit, and the apparatus further includes: circuitry coupled to the plurality of electrodes to sequentially actuate the plurality of electrodes, and in response to the sequential actuation, draw the sample fluid droplet along the microfluidic path.

13. A method comprising: flowing a fluid including a sample fluid droplet along a first microfluidic path of a digital microfluidic (DMF) device; sequentially actuating a plurality of electrodes disposed proximal to a second microfluidic path of an interface device coupled to the DMF device; and in response to the sequential actuating, drawing the sample fluid droplet into a fluidic inlet of the interface device via the actuation of an electrode of the plurality of electrodes disposed proximal to the fluidic inlet; and flowing the sample fluid droplet along the second microfluidic path of the interface device.

14. The method of claim 13, wherein sequentially actuating the plurality of electrodes includes introducing electrowetting forces on the fluid including the sample fluid droplet by: actuating the electrode of the plurality of electrodes to draw the sample fluid into the fluidic inlet, the electrode being disposed proximal to the fluidic inlet; and sequentially actuating at least a subset of the remaining plurality of electrodes to move the sample fluid droplet along the second microfluidic path of the interface device.

15. The method of claim 13, where the second microfluidic path includes a conduit formed in a housing of the interface device, the conduit coupled to the fluidic inlet, and the method further includes: determining a parameter of the sample fluid droplet using a sensor supported by the housing and disposed with the conduit.