Method and device for volume partitioning in a digital microfluidic system

Abstract

According to an aspect, there is provided a device and method for manipulating a sample droplet. The method comprises disposing a sample droplet onto a movement grid, moving the sample droplet along a path by electrowetting-on-dielectric forces. The path includes a divider that divides the sample droplet into at least a retained volume to be held in a retaining area and a remainder volume to be moved along the path. The movement grid includes a top layer and a bottom layer, the bottom layer comprising a dielectric layer coated with a bottom hydrophobic layer, the top layer comprising a conductive top plate coated with a top hydrophobic layer, the top layer and the bottom layer defining a cavity, and selectively actuatable regions of the dielectric layer for moving a sample droplet within the cavity via electrowetting-on-dielectric forces.

Description

METHOD AND DEVICE FOR VOLUME PARTITIONING IN A DIGITAL MICROFLUIDIC SYSTEMCROSS-REFERENCE

[0001] This application claims all benefit including priority to U.S. Provisional Patent Application 63 / 652,844, filed 29 May 2024, and entitled “METHOD AND DEVICE FOR VOLUME PARTITIONING IN A DIGITAL MICROFLUIDIC SYSTEM”, the entire contents of which are hereby incorporated by reference herein.TECHNICAL FIELD

[0002] The disclosure relates generally to biological analytics, and more particularly to systems and methods for blood plasma analysis.BACKGROUND

[0003] Blood tests are an invaluable tool in the field of healthcare and research. They can be instrumental in determining physiological and biological states. For example they can be used to detect specific components of blood (e.g., glucose, cholesterol, etc.). These blood tests often necessitate blood collection and subsequent processing (if needed) to render quantitative or qualitative analytes.

[0004] Despite the ubiquity of blood tests, they can still prove to be challenging to implement in, for example, an at-home setting without a healthcare practitioner. Furthermore, current methods of conducting complex blood tests (e.g., ones with specific methodologies to produce the relevant analyte) may still leave room for human error. High volumes of sample may make it more challenging to conduct the necessary analysis because the subject may not have sufficient blood to give or may not want to give that much blood. Such considerations can limit the accuracy and / or types of blood tests that can be conducted off of a single collection sample.

[0005] Improvements in the field of blood tests are desirable.SUMMARY

[0006] According to an aspect, there is provided a device for sample analysis. The device includes a movement grid and a divider disposed in a cavity of the movement grid. The movementgrid includes a top layer and a bottom layer. The bottom layer includes a dielectric layer coated with a bottom hydrophobic layer. The top layer includes a conductive top plate coated with a top hydrophobic layer. The top layer and the bottom layer define the cavity. A plurality of digital microfluidic (DMF) electrodes are configured to selectively actuate regions of the dielectric layer to move a sample droplet within the cavity between regions corresponding to each of the plurality of DMF electrodes via electrowetting-on-dielectric forces. The divider includes a path for the sample droplet to be moved along by the electrowetting-on-dielectric forces. The divider is configured to divide the sample droplet into at least a retained volume to be held in a retaining area and a remainder volume to be moved along the path.

[0007] In some embodiments, the device further includes a magnetic field generator configured to selectively apply a magnetic field within at least a portion of the path to manipulate magnetic particles within the sample droplet.

[0008] In some embodiments, the magnetic particles are functionalized magnetic beads.

[0009] In some embodiments, the device is configured to recover and wash the magnetic particles with a wash droplet.

[0010] In some embodiments, the magnetic field is oriented to move the magnetic particles into the retained volume.

[0011] In some embodiments, the magnetic field is applied to be substantially aligned with an outlet of the path and substantially perpendicular to an inlet of the path.

[0012] In some embodiments, the magnetic field holds the magnetic particles in the retained volume and the divider includes one or more separated DMF electrodes that are configured to hold the retained volume in place in part by electrowetting-on-dielectric forces applied by the one or more separated DMF electrodes.

[0013] In some embodiments, the divider includes a dividing surface configured to constrain the path to divide the sample droplet into at least the retained volume and the remainder volume.

[0014] In some embodiments, the dividing surface includes a hydrophobic surface positioned in a gap between two of the plurality of DMF electrodes.

[0015] In some embodiments, the divider is configured to separate a liquid phase of the sample droplet from a substantially solid phase of the sample droplet.

[0016] In some embodiments, the path is defined by an edge of one or more switched off DMF electrodes. In such embodiments, the switched off DMF electrodes provide a magnetic barrier to the droplet (not a physical one).

[0017] In some embodiments, the size and shape of the retaining area and an applied magnetic field define a magnitude of the retained volume for a given fluid.

[0018] According to another aspect, there is provided a method of manipulating a sample droplet. The method includes disposing a sample droplet onto a movement grid and moving the sample droplet along a path by the electrowetting-on-dielectric forces. The path includes a divider that divides the sample droplet into at least a retained volume to be held in a retaining area and a remainder volume to be moved along the path. The movement grid includes a top layer and a bottom layer. The bottom layer includes a dielectric layer coated with a bottom hydrophobic layer. The top layer includes a conductive top plate coated with a top hydrophobic layer. The top layer and the bottom layer define a cavity and selectively actuatable regions of the dielectric layer for moving a sample droplet within the cavity via electrowetting-on-dielectric forces.

[0019] In some embodiments, the method includes applying a magnetic field with at least a portion of the path to manipulate magnetic particles within the sample droplet.

[0020] In some embodiments, the magnetic particles are functionalized magnetic beads.

[0021] In some embodiments, the method further comprises recovering and washing the magnetic particles with a wash droplet.

[0022] In some embodiments, the magnetic field is applied to be substantially aligned with an outlet of the path and substantially perpendicular to an inlet of the path.

[0023] In some embodiments, the magnetic field is oriented to move the magnetic particles into the retained volume.

[0024] In some embodiments, the magnetic field holds the magnetic particles in the retained volume and the divider includes one or more separated DMF electrodes that are configured tohold the retained volume in place in part by electrowetting-on-dielectric forces applied by the one or more separated DMF electrodes.

[0025] In some embodiments, the divider includes a dividing surface configured to constrain the path to divide the sample droplet into at least the retained volume and the remainder volume.

[0026] In some embodiments, the dividing surface comprises a hydrophobic surface positioned in a gap between at least two of the plurality of DMF electrodes.

[0027] In some embodiments, the method includes recovering the retained volume from the divider.

[0028] In some embodiments, the divider is configured to separate a liquid phase of the sample droplet from a substantially solid phase of the sample droplet.

[0029] In some embodiments, the path comprises an edge of one or more switched off DMF electrodes.

[0030] In some embodiments, the size and shape of the retaining area and an applied magnetic field define a magnitude of the retained volume for a given fluid.

[0031] In some embodiments, the method includes moving the retained volume away from the divider.

[0032] In some embodiments, the method includes moving an additional droplet into the divider to join the retained volume and moving at least a portion of the joined additional droplet and retained volume towards an electrochemical sensor.

[0033] In some embodiments, the method includes moving at least a portion of the remainder volume towards an electrochemical sensor.

[0034] Further details of these and other aspects of the subject matter of this application will be apparent from the detailed description included below and the drawings.DESCRIPTION OF THE DRAWINGS

[0035] Reference is now made to the accompanying drawings, in which:

[0036] FIG. 1 is a system diagram of an at-home health monitor system, according to some embodiments.

[0037] FIG. 2 is a system diagram of an embodiment analyzer system, according to some embodiments.

[0038] FIG. 3A is a top view of an embodiment analyzer system, according to some embodiments.

[0039] FIG. 3B is a perspective view of an embodiment analyzer system, according to some embodiments.

[0040] FIG. 3C is a side view of an embodiment analyzer system, according to some embodiments.

[0041] FIG. 4 is a perspective view of a chip with digital microfluidic components, according to some embodiments.

[0042] FIG. 5A is a plan view of a chip, according to some embodiments.

[0043] FIG. 5B is a plan view of a chip with a virtual bulk fluid reservoir, according to some embodiments.

[0044] FIG. 6 is a top view of digital microfluidic electrodes with droplets contained thereon, according to some embodiments.

[0045] FIG. 7A is a cross-sectional elevation view of a chip, according to some embodiments.

[0046] FIG. 7B is a cross-sectional elevation view of a chip, according to some embodiments.

[0047] FIG. 8 is a plan view of a chip with reagents provided thereon, according to some embodiments.

[0048] FIG. 9A is a cross-sectional elevation view of a single electrochemical sensor, according to some embodiments.

[0049] FIG. 9B is a cross-sectional elevation view of a multilayer electrochemical sensor, according to some embodiments.

[0050] FIG. 9C is a perspective view of an electrochemical sensor with reagents provided thereon, according to some embodiments.

[0051] FIG. 10A is a plan view of an electrochemical sensor, according to some embodiments.

[0052] FIG. 10B is a plan view of an electrochemical sensor with carbon nano-tubes, according to some embodiments.

[0053] FIG. 11A illustrates a droplet moving from the movement grid to an electrochemical sensor, according to some embodiments.

[0054] FIG. 11B illustrates the movement grid and an electrochemical sensor, according to some embodiments.

[0055] FIG. 12 illustrates a blood plasma separator locking mechanism, according to some embodiments.

[0056] FIG. 13A is a plan view of a movement grid with a divider included thereon, according to some embodiments.

[0057] FIG. 13B and FIG. 13C are plan views of movement grids with an alternative divider included thereon, according to some embodiments.

[0058] FIG. 14A-14F show a series of plan views of the movement grid with the divider included thereon of FIG. 13A showing sample droplet cleavage and magnetic particle recovery, according to some embodiments.

[0059] FIG. 14G-FIG. 141 show a series of plan views of a movement grid showing the retention of magnetic particles using subdivided DMF electrodes, according to some embodiments.

[0060] FIG. 15 is a flowchart of example droplet manipulation operations performed by the system of FIG. 2 on the movement grid of FIG. 13A, according to some embodiments.

[0061] FIG. 16 is a schematic diagram of a computing device, according to some embodiments.DETAILED DESCRIPTION

[0062] Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways.

[0063] The improvements described herein are generally directed to systems and methods for improved health monitoring hardware and software. The improvements described herein can be used to make at-home health monitoring and blood tests more reliable and robust. In particular, the improvements described herein can be used in systems designed for chip- or cartridge-based analyte tests (e.g., blood or blood plasma) carried out using a testing platform such as an analyzer system.

[0064] Such chip-based testing systems can comprise a sample collection system, an (optionally disposable) chip, and an analyzer system. The sample collection system can be used to collect a sample (e.g., blood plasma) from the subject. The sample may then be provided to the chip housed in the system analyzer. The chip may be configured with various components to analyze the sample which may be operated by the system analyzer. Separation of chip and system analyzer may permit the use of multiple chips (e.g., to carry out different analyses or to minimize contamination between samples). The system may further involve the use of general and / or specialty software embedded within the analyzer, on an app, and / or carried out by cloud computing. When operated, the chip-based system may be capable of carrying out analyses on the sample. Such analysis may be used to diagnose a subject of a condition, monitor various biological metrics or other metrics, or carry out other objectives.

[0065] The sample collection system can be configured to collect a sample (e.g., blood) from the subject. The sample collection system can be configured to carry out specific operations with the sample prior to providing the sample to the chip. For example, the sample collection system may be configured to filter the sample. As a further example, the sample collection system may be configured to carry out plasma separation for blood samples. The sample collection system may further be configured with an adaptor to aid in the provision of the sample to the chip after collection. Such adaptors can ensure a consistent delivery of sample to the chip, which may limitcontamination of the sample by external contaminants or ensure that the sample is delivered in a manner to ensure it will be usable by the chip.

[0066] Aspects of various embodiments are described through reference to the drawings.

[0067] FIG. 1 is a system diagram of an at-home health monitor system 10, according to some embodiments.

[0068] The system 10 can include a chip 100, a user device 200, and an analyzer system 300. The system components can work together to execute a test on a sample collected using the sample collection system described above. For example, a user may be able to detect the type of the chip 100 (e.g., the type of test executable by the chip or the configuration of the tests on the chip 100). The user may be able to detect this from the chip 100, for example, by scanning a barcode, QR code, RFID tag (e.g., NFC), or EEPROM on the chip using the user device 200. Alternatively, the user may be asked to input a code on the chip 100 into the user device 200. The user may then place the chip 100 or otherwise insert the chip 100 into the analyzer system 300. The user device 200 may then select or otherwise determine the microfluidic operations sequences from the chip type of chip 100 and transmit the microfluidic operations sequence to the analyzer system 300 to carry out the testing on a sample. The analyzer system 300 may be configured to transmit the test results back to the user device 200.

[0069] In some embodiments, the user device 200 may include a processor 202, a memory 204, an I / O interface 206, and a network interface 208. The user device may be configured to detect or receive a chip type (e.g., a chip ID) from the chip 100 by, for example, scanning with the user device 200 or input by the user (e.g., by the I / O interface 206). In alternative embodiments, the chip type may be detected by the analyzer system 300 when the chip 100 is therein inserted and this information may be transmitted to the user device 200 using the network interface 208. The user device 200 determines the microfluidic operations sequence based on the chip type. The user device 200 may pull the operations from the memory 204 or it may communicate with an external server (not shown) to pull the operations. The user device 200 may transmit these instructions to the analyzer system 300 using the network interface 208. While or after carrying out the microfluidic operations sequence, the analyzer system 300 may transmit per-channel raw electrochemical data (or error data as the case may be) to the user device 200. The user device 200 may be configured to process the data received from the analyzer system 300 and provide the user (or another third party) with results of the test.

[0070] In some embodiments, the analyzer system 300 may be configured to carry out instructions received by the user device 200 and provide results from the sensors to the user device 200. In some embodiments, the analyzer system 300 may be configured to carry out some processing operations onboard its own system (e.g., microfluidic operations sequence processing, basic fault-tolerance operations, some analytical processing, etc.). It is to be understood that the processes described herein as occurring on the user device 200 or the analyzer system 300 may equally be carried out by or in conjunction with the opposite component.

[0071] In some embodiments, the user device 200 may be configured to transmit and receive information from an external server (not shown). This may be used to upload test results data from the user device 200 or download software updates onto the user device 200. In some embodiments, the user device 200 may be configured to transmit software updates to the analyzer system 300. In some embodiments, the analyzer system 300 may be configured to communicate directly with an external server.

[0072] The processor 202 may include an app 210 configured to execute operations related to testing and orchestrating the functionality described herein. The processor 202 may include details and variations as described below with reference to the processor 1602 of FIG. 16 below.

[0073] The app 210 may be configured to receive the chip type (e.g., by scanning the chip 100, by user input, or through information received from the analyzer system 300), instruct the analyzer system 300 to carry out a test by transmitting microfluidic operations sequences, receive information (e.g., per-channel electrochemical data) from the analyzer system 300, and present the results to the user. The app 210 may further be configured to receive updates from an external server and (where appropriate) push those to the analyzer system 300.

[0074] The memory 204 may be configured to store information related to the operation of the system. For example, the memory 204 may store microfluidic operations sequences associated with a plurality of chip types. The memory 204 may further store information related to a user profile which may be used to present data to a user with their preferences therein input, or with historical results presented therein. The memory 204 may include details and variations as described below with reference to the memory 1604 of FIG. 16 below.

[0075] The I / O interface 206 may include interfaces to enable the user device 200 to interface with user inputs (e.g., keyboards, buttons, touchpads, switches, etc.) and outputs (e.g., screens,indicators, etc.). The I / O interface 206 may include details and variations as described below with reference to I / O interface 1606 of FIG. 16 below.

[0076] The network interface 208 may connect the user device 200 to other system components. For example, the user device 200 may be configured to communicate with an external device (e.g., the analyzer system 300) to deliver controls or receive results. As another example, the user device 200 may be configured to receive updates from, for example, a server or transmit data (user results, error reports, etc.) to the server. The network interface 208 may include details and variations as described below with reference to the network interface 1608 of FIG. 16 below.

[0077] FIG. 2 is a system diagram of an embodiment analyzer system 300, according to some embodiments.

[0078] The analyzer system 300 may include a processor 302, a memory 304, and a chip interface 306. The analyzer system 300 may further optionally include one or more of an I / O interface 308 and a network interface 310. The analyzer system 300 may be configured with a housing. The housing may be configured to physically receive a chip 100 (e.g., with the cinching mechanism 316). The chip 100, when received, may communicate with the analyzer system 300 through, for example, the chip interface 306. The chip 100 and the analyzer system 300 may communicate to enable the chip 100 to transmit information about its systems (e.g., type of chip, feedback, signals, etc.) and the analyzer system 300 to transmit instructions to the chip 100.

[0079] The processor 302 may include a digital microfluidics (DMF) controller 312. The processor 302 may be configured to transmit (e.g., send or receive) data using any one or more of the chip interface 306, I / O interface 308, and network interface 310. The processor 302 may be configured to pull instructions from the memory 304 or from another component (e.g., an external device or the cloud). The processor 302 may be configured to pull and execute different instructions and / or modify instructions based on several factors (e.g., the type of chip therein inserted, user instructions, the test panel to be performed, updates from an external device or the cloud, calibration steps, etc.). The processor 302 may include details and variations as described below with reference to the processor 1602 of FIG. 16 below.

[0080] The DMF controller 312 may be used to perform microfluidic operations on the chip 100. The DMF controller 312 may be configured to dispense droplets 110 (e.g., sample droplets) from the reservoir 102, move them between DMF electrodes 106, and conduct mixing operations.The DMF controller 312 may be configured to validate movement of the droplets 110 and provide some error correction.

[0081] The chip 100 (as described in greater detail below) may comprise, for example, a sandwich consisting of an area array of droplet-sized cells on the bottom, a cavity for droplets in the middle, and a continuous backplane which extends over all individual cells on the top. The cells and the backplane may be electrically insulated from the droplets by, for example, a thin coating. Droplets 110 can be induced to move from one cell region to another adjacent cell region through specific application of electrical forces (e.g., application of an alternating high voltage between an individual cell and the backplane). The DMF controller 312 can manipulate droplets 110 (e.g., microdroplets) on a platform by controlling a set of insulated electrodes. The DMF controller 312 can control the electronics in the chip 100 to drive movement of the droplets 110 across the chip 100 as needed.

[0082] In some embodiments, the chip 100 may have different configurations, sizes, and shapes of electrodes which may vary from chip to chip. Furthermore, the chip 100 may include other structures to alter droplet movement. Reagents printed on the chip 100 may be varied. The DMF controller 312 may be configured to manipulate droplets 110 on different chips 100 depending on that chip’s 100 configuration, size, and shape of the electrodes and other factors.

[0083] When a polar liquid (e.g., blood plasma or water) sits atop a hydrophobic surface it will form into a droplet under surface tension. This orientation helps the liquid minimize the surface area with the hydrophobic surface. A drop of polar liquid sitting atop a hydrophilic surface will spread out and attempt to wet the surface.

[0084] The hydrophobicity of the surface can be modulated using electrical fields. For example, by placing a droplet 110 on a surface with an electrode thereunder, the electrode can modulate the electric fields applied to the droplet 110 thereby modulating the effective hydrophobicity / hydrophilicity of the surface. The droplet 110 can be separated from the electrode with a dielectric layer to prevent direct electrical contact between the electrode and the liquid. This process is called electrowetting-on-dielectric (EWOD). By modulating the electric fields of two adjacent cells in an array of cells, the DMF controller 312 can manipulate a droplet 110 to move between these surfaces.

[0085] The DMF controller 312 may further be configured to monitor feedback from a droplet 110 as it moves (or does not move) to validate and correct any deviations in intended movementpatterns. Furthermore, this feedback can be used to verify droplet position and volumes. This may be convenient for fault-tolerant microfluidic operations. Moving droplets 110 may not always succeed and it is beneficial if the system 300 can correct itself rather than necessitating a new sample entirely. Viscous fluids (e.g., diluted plasma) may be especially difficult to control with microfluidics.

[0086] Droplet feedback systems can include, for example, a camera with, for example, computer-vision-aided tracking. These cameras however may be expensive and difficult to clean. This may make other more economical droplet feedback systems preferable for consumer products.

[0087] In one implementation, the DMF controller 312 can be configured to detect the presence of a volume of liquid on a surface. In such implementations, the DMF controller 312 can detect whether a set volume of liquid is present on a goal DMF electrode (which may be one in a series of goal DMF electrodes for complex or long range movement patterns). If the set volume is not detected, then the DMF controller 312 can carry out the operation again until, for example, the droplet 110 moves.

[0088] In another implementation, the DMF controller 312 can be configured to rely on capacitive feedback from a droplet 110 on the DMF electrode. For example, the DMF controller 312 may apply an input voltage pulse (e.g., a transient DC voltage) to each DMF electrode which results in an output pulse with an amplitude roughly proportional to the droplet volume. Using these amplitudes, more precise measurement of volume of the droplet 110 can be obtained on a DMF electrode-by-electrode basis.

[0089] The analyzer system 300 includes a potentiostat 314 configured to control and receive signals from one or more electrochemical sensors on an inserted chip 100. The potentiostat 314 may be configured to perform, for example, assays using electroanalytical methods (e.g., potentiodynamic operations) such as, for example, cyclic- voltammetry (CV) or chronoamperometry (CA). The potentiostat 314 may also be configured to perform other electroanalytical methods.

[0090] The DMF controller 312 may be configured to transport droplets 110 to an electrochemical sensor and the potentiostat 314 may be configured to carry out an electrochemical operation on the droplet 110. For example, the potentiostat 314 may beconfigured to apply specific and / or dynamic voltages to the sample and facilitate measurement of the electrical characteristics (such as current).

[0091] The memory 304 may store instructions executable by the analyzer system 300. For example, the memory 304 may store instructions for a variety of different types of chips 100 and may select which instructions to execute based on, for example, the type of chip 100 inserted, a selection made by the user on the analyzer system 300, a selection made by the user on an external device, or some other method. The memory 304 may include details and variations as described below with reference to the memory 1604 of FIG. 16 below.

[0092] The chip interface 306 may be configured to interface with any chips 100 inserted or otherwise connected to the analyzer system 300. For example, a chip 100 may be seated within the analyzer system 300 and the chip 100 may be connected to the analyzer system 300. In particular, the DMF controller 312 may be connected to the DMF control system on the chip 100 and the potentiostat 314 may be connected to the electrochemical sensors on the chip 100. The chip interface 306 may include a single interface through which all connections are made or it may include a plurality of connections. The connection may be physical (enabling the analyzer system 300 to apply electrical forces through the chip 100) or it may be remote (for example, the analyzer system 300 activates the components in the chip 100 via a remote connection).

[0093] The I / O interface 308 may include interfaces to enable the analyzer system 300 to interface with user inputs (e.g., keyboards, buttons, touchpads, switches, etc.) and outputs (e.g., screens, indicators, etc.). The I / O interface 308 may include details and variations as described below with reference to I / O interface 1606 of FIG. 16 below.

[0094] The network interface 310 may connect the analyzer system 300 to other system components. For example, the analyzer system 300 may be configured to communicate with an external device (e.g., a user's mobile phone running an app) to deliver results or receive controls. As another example, the analyzer system 300 may be configured to receive updates from, for example, a server or transmit data (user results, error reports, etc.) to a server. The network interface 310 may include details and variations as described below with reference to the network interface 1608 of FIG. 16 below.

[0095] The analyzer system 300 may further comprise other optional components. For example, it may be configured with a vibrating component to vibrate the analyzer system 300 or parts thereof, for example, to dislodge a pinned droplet.

[0096] FIG. 3A is a top view of an embodiment analyzer system 300, according to some embodiments. FIG. 3B is a perspective view of an embodiment analyzer system 300 according to some embodiments.

[0097] An example chip 100 is illustrated as being in the analyzer system 300. As described above, the system analyzer 300 may be configured to interface with the chip 100 through a chip interface 306 to drive the digital microfluidic operations and / or to drive and receive information about the electrochemical sensors.

[0098] FIG. 3C is a side view of an embodiment analyzer system 300, according to some embodiments.

[0099] In some embodiments, a cinching mechanism 316 can couple the chip 100 with the analyzer 300 to help ensure electrical contact between the chip 100 and the analyzer 300. The cinching mechanism 316 can include a cinching motor 318, a cinching cam 320, and a moving platform 322. After being inserted into the analyzer 300, the chip 100 can be clamped in place. For example, the cinching motor 318 may actuate the cinching cam 320 and the moving platform 322. The moving platform 322 can push down on the chip 100. The moving platform’s 322 vertical position is set by the rotational position of a cinching cam 320 which can be powered by the cinching motor 318. Once cinched, pins on the bottom of the chip 100 may be in electrical contact with the analyzer's 300 pins. In some embodiments, the pins may be stationary. In some embodiments, the pins may be spring-loaded.

[0100] FIG. 4 is a perspective view of a chip 100 with digital microfluidic components, according to some embodiments.

[0101] The chip 100 (e.g., which may also be referred to herein as a cartridge) can comprise digital microfluidic components enclosed within a sealed cartridge. The digital microfluidic components can be used to manipulate droplets 110 (e.g., of a sample of blood or plasma thereof) within the enclosed space and to maneuver droplets 110 to reagents and sensor cells. The chip 100 may enclose the samples in an enclosed system that can be, for example, sealed from outside air or resist leakage of internal liquids.

[0102] FIG. 5A is a plan view of a chip 100, according to some embodiments.

[0103] The chip 100 includes a reservoir 102, a movement grid 104, and electrochemical sensors 108. As described above, the DMF components may connect or couple with an analyzersystem 300 such that the analyzer system 300 can control the digital microfluidics on the chip 100 and sense and control the electrochemical sensors 108.

[0104] Samples may be provided to the chip 100 at or near the reservoir 102. The reservoir 102 may use electrowetting forces to hold a bulk sample in place and to deliver droplets 110 of the sample to the movement grid 104 for further operations.

[0105] The movement grid 104 includes a plurality of DMF electrodes 106. In some embodiments, the DMF electrodes 106 can be identical in construction or can be designed with specific regional functions. In some embodiments, a DMF controller 312 may be configured to selectively activate one or more of the DMF electrodes 106 to drive movement of a droplet 110 from DMF electrode 106 to DMF electrode 106. The movement grid 104 may also include deposits of any reagents, for example, stored in dry form on a particular DMF electrode 106 (described in greater detail below). During use, the movement grid 104 may receive or take a droplet 110 from the reservoir 102, move it using the DMF electrodes 106, optionally mix the droplet 110 with a reagent stored on a particular DMF electrode 106, and bring the droplet 110 to an electrochemical sensor 108 for analysis.

[0106] The reservoir 102 can include two regions 102a and 102b. The first region 102a may be configured to receive the sample (e.g., a diluted plasma sample). The second region 102b may be configured to aliquot a droplet by pulling it and then pinching it off from the main reservoir bulk (e.g., region 102a). The regions 102a and 102b may include electrodes to carry out their intended purpose. Other configurations for the reservoir 102 are possible.

[0107] The electrochemical sensors 108 may include electrodes capable of monitoring and / or driving electroanalytical processes. There are twelve electrochemical sensors 108 shown on chip 100 (six along the top and six along the bottom). Other configurations are possible. In some embodiments, a potentiostat 314 can control the electrochemical sensors 108. Though described as electrochemical sensors 108, one or all of the sensors 108 may be configured for different sensor modalities.

[0108] Though one particular embodiment of the reservoir 102, movement grid 104, and electrochemical sensors 108 is illustrated, many more configurations are possible without deviating from the teachings of the present disclosure.

[0109] FIG. 5B is a plan view of a chip 100 with a virtual bulk fluid reservoir 142, according to some embodiments.

[0110] In some embodiments, the functionality of bulk fluid reservoir 102 can be replaced with a virtual bulk fluid reservoir 142.

[0111] The virtual reservoir 142 illustrated in FIG. 5B is larger (and specifically longer) than the reservoir 102 as illustrated in FIG. 5A. 5 The larger reservoir 142 can hold a larger volume of sample liquid and it can also enable more dispensing strategies without encroaching on the movement grid 104. The larger reservoir 142 can allow the blood collector geometry (e.g., blood plasma separator 500) to sit outside the analyzer 300. Distancing the blood collector geometry from the analyzer 300 may be beneficial as it may reduce the risk of incompatibility as between the blood collector and the analyzer 300 should the blood collector be updated (e.g., newer versions of the blood collector can be developed without as much risk that it may not be usable with older models of an analyzer 300, for example due to spatial hindrance). While these advantages are described with reference to a virtual reservoir 142, these advantages may also be achieved with a standard reservoir 102 as well.

[0112] FIG. 6 is a top view of digital microfluidic electrodes 106 with droplets contained thereon, according to some embodiments.

[0113] By manipulating the electrical forces surrounding the individual DMF electrodes 106, the droplets 110 may be compelled to move between adjacent DMF electrodes 106 or stay in place.

[0114] FIG. 7A is a cross-sectional elevation view of a chip 100 across line A-A (FIG. 5A), according to some embodiments.

[0115] FIG. 7B is a cross-sectional elevation view of a chip 100 across line A-A (FIG. 5A), according to some embodiments.

[0116] The chip 100 may include a printed circuit board (PCB) 112, a dielectric layer 114, a bottom hydrophobic coating 118, an adhesive 116, a top hydrophobic coating 119, a top plate 120, and an enclosure 122 defining a cavity 126 for a sample droplet 110. An ITO spacer 127 may also define the cavity 126. The chip 100 may also include an EC spacer 124, an ITO spacer 127, and electrochemical sensors 108.

[0117] The PCB 112 may comprise a printed circuit board with or without solder mask. The PCB 112 can be divided into DMF electrodes 106 for droplet movement and microfluidic operations and, for example, electrochemical sensor 108 electrodes for running assays (as seen in FIG. 5A). The electrodes may be coated using an immersion gold process with a protective layer such as palladium beneath to improve electrochemical signal reliability and resist corrosion during storage.

[0118] The dielectric layer 114 may be used to induce electrowetting-on-dielectric, the phenomenon that allows for droplet 110 movement on the grid. In some embodiments, the dielectric layer 114 can be a UV / heat curable liquid with a high dielectric strength. Thickness of the dielectric layer 114 may be controlled by the fabrication process used such as spin coating, dip coating, etc. In some embodiments, the dielectric layer 114 may be 2.5-10 pm thick, or preferable 5-10 pm thick, and made of polyester film, polyester core tape, or polyimide film. Thinner dielectric layers can enable droplet movement at lower actuation voltages. Thicker dielectric layers can better resist dielectric breakdown caused by pinholes. The dielectric layer 114 is bonded to the PCB 112 using an adhesive 116. In some embodiments, the adhesive 116 is an adhesive coating applied to one side of the PCB 112.

[0119] Hydrophobic coatings 118, 119 may be used to coat the dielectric layer 114 and top plate 120 to aid droplet 110 movement and create the contact angle required for movement by electrowetting-on-dielectric. In some embodiments, Cytonix FluoroPei PFC 1101V can be used. After coating the dielectric layer 114, the FluoroPei can be cured. The thickness of the hydrophobic coatings 118, 119 may be less than one micrometer.

[0120] ITO spacer 127 (which may be a spacing adhesive) can be used to hold the top plate 120 in place and provide enough space for the droplets 110 to move underneath. In some embodiments, the spacer 127 height may be between 100 and 300 micrometers. In one specific embodiment, the spacing may be approximately 235pm.

[0121] The top plate 120 can be a conductive top plate to close the circuit through the PCB 112, dielectric layer 114, and droplets 110. In some embodiments, the top plate 120 can be connected to the base PCB 112 using a deformable conductive material (e.g., copper tape). In some embodiments, the top plate 120 may be Indium-Tin-Oxide (ITO)-coated glass. Transparency allows the droplets 110 to be seen during movement. Other conductive rigidmaterials such as materials of another PCB or injection molded conductive parts may be used when direct visual contact with the droplets 110 is not required.

[0122] Enclosure 122 can provide a sealed case to seal any reagents (described in greater detail below) and hydrophobic coatings 118 and 119 inside the chip 100 for safe handling and disposal by consumers.

[0123] On the periphery of the chip 100 are the electrochemical sensors 108. The electrochemical sensors 108 are described in greater detail below. The electrochemical sensors 108 may optionally interoperate with the EC spacer 124 and hydrophilic layers 136 to receive sample. In some embodiments, the electrochemical sensors 108 do not use hydrophilic layers 136 to receive the sample (e.g., the hydrophobic coating 119 and / or 118 may be masked to encourage the sample droplet 110 to enter the sensor 108), as seen in FIG. 7A. In some embodiments, the EC spacer 124 provides a 15 region for the electrochemical reaction to be carried out. In some embodiments, the hydrophilic layers 136 can attract the sample droplet 110 into the sensor 108. In some embodiments, the hydrophilic layers 136 can overlap on the hydrophobic coating 118 (seen in the bottom hydrophilic layer 136 of FIG. 7B). This may advantageously improve the reliability of the sensors 108 by improving droplet transfer.

[0124] FIG. 8 is a plan view of a chip 100 with reagents 128 provided thereon, according to some embodiments.

[0125] In some embodiments, some chips 100 may include deposited reagents 128 (inclusive of reagents 128a, 128b, and 128c). These reagents 128 may be any reagents required to be mixed into plasma / diluent droplets 110 before moving to the electrochemical sensors 108 (inclusive of sensors 108a and 108b). In some embodiments, different reagents 128 may be placed on the grid which may ultimately be tested by different electrochemical sensors 108 testing for different analytes or phenomena. For example, one droplet 110 may be directed to mix with reagent 128a and then analyzed by sensor 108a while another droplet 110 may be directed to mix with reagent 128b, made to wait while a reaction occurs, mixed with reagent 128c, and analyzed by sensor 108b which may be configured differently than sensor 108a. Example reagents sensors 108 can include electrochemical sensors, dilution factor sensors, total cholesterol (TC) sensors, high-density lipoprotein (HDL) sensors, and triglyceride (TRG) sensors. Furthermore, some sensors 108 may be coated with coatings or otherwise configured to carry out a particular analysis.

[0126] FIG. 9A is a cross-sectional elevation view of a single electrochemical sensor 108 across line B-B (FIG. 5A), according to some embodiments.

[0127] The electrochemical sensor 108 may be provided on a PCB 112. The electrochemical sensor 108 may comprise a three-electrode set up with a working electrode 130, a counter electrode 132, and a reference electrode 134. Other electrode set ups are conceived (e.g., a counter electrode 132 split into two halves 132A and 132B). The electrochemical sensor 108 may be situated underneath one or more hydrophilic layers 136. In some embodiments, this may include a multi-layered assembly that creates a cavity with the electrodes exposed to the liquid. The assembly may consist of multiple hydrophilic layers 136, spacer adhesives 124 composed of double and / or single sided tapes (shown in FIG. 9B). The hydrophilic layers 136 could be natively hydrophilic, or made hydrophilic through the addition of different liquids dried on the surface such as sugars, salts, surfactants, hydrogels, etc. The working electrode 130 may, in some embodiments, be coated with a coating 131 comprising a membrane that may be enzyme modified. The droplet reaction mixture 138 (e.g., a plasma reaction mixture) may be situated on the working electrode and be analyzed by the electrochemical sensor 108. The coating 131 may include a porous membrane. This porous membrane may be deposited on the working electrode 130 using a deposition printer. The coating 131 may contain enzymes, antibodies, reagents, etc. as required.

[0128] As described above, the electrochemical sensor 108 may be made to perform, for example, assays using electroanalytical methods (e.g., potentiodynamic operations) such as, for example, cyclic-voltammetry (CV) or chronoamperometry (CA). Other electroanalytical methods are conceived. The electrochemical sensor 108 may be controlled by a potentiostat 314 on an analyzer system 300.

[0129] FIG. 9B is a cross-sectional elevation view of a multilayer electrochemical sensor 108, according to some embodiments.

[0130] Precipitating certain sample components (e.g. cholesterols) on the movement grid 104 can degrade droplet movement (up to and including a complete stop or "pinning") in the vicinity due to accelerated biofouling of the electrowetting surface. Using a hydrophilic layer 136 such as an EC mesh to precipitate e.g. cholesterols instead of carrying the precipitation out on the movement grid 104 can obviate the issue of degraded movement because the droplet 110 is already in its final resting place and there is no need to move it away from that location afterwards.For example, the sample droplet 110 may be drawn into the upper droplet reaction mixture portion 138 by the upper hydrophilic layer 136, react with a reagent doped in the lower hydrophilic layer 136 to precipitate a component of the sample droplet 110, and then be drawn into the lower droplet reaction mixture portion 138 by the lower hydrophilic layer 136 to contact the working electrode 130.

[0131] FIG. 9C is a perspective view of an electrochemical sensor 108 with reagents provided thereon, according to some embodiments.

[0132] In some embodiments, the hydrophilic layers 136 can also be loaded with reagents. This can enable the reagents to be mixed directly above the sensor 108. In some embodiments, a hydrophilic layer 136 may be in contact with the electrochemical sensor 108 (cell A). In some embodiments, the hydrophilic layers 136 may both be above the electrochemical sensor 108 (cell B). In some embodiments, the hydrophilic layers 136 may be above the electrochemical sensor 108 in much closer proximity to it (cell C). The heights may vary.

[0133] FIG. 10A is a plan view of an electrochemical sensor 108, according to some embodiments.

[0134] The electrochemical sensor 108 may be configured with a three-electrode set up. The electrochemical sensor 108 may be configured with a circular central working electrode 130, and a counter electrode 132, and a reference electrode 134.

[0135] The electrochemical sensor 108 may include gold. Standard PCB manufacturing techniques may be used. The electrochemical sensor 108 may have many sizes and shapes / numbers of electrodes while falling within the teachings of this description.

[0136] The electrochemical sensor 108 may include a reservoir made up of a small cut-out in, for example, a hydrophobic layer above the electrodes to allow a microdroplet of fluid to sit on the electrode.

[0137] FIG. 10B is a plan view of an electrochemical sensor 108 with carbon nano-tubes 133, according to some embodiments.

[0138] Providing a carbon nano-tube porous ink 133 to the electrochemical sensor 108 can help entrap active biorecognition elements and other reagents within the vicinity of the working electrode 130 while enhancing the stability of the electrochemical sensor 108. The counterelectrode 132 can be split in two halves 132A and 132B. The porous ink (membrane) 133 can consist of a binder, such as hydroxyethyl cellulose and / or cellulose acetate, to encapsulate the active biorecognition elements such as enzymes, antibodies, aptamers, and / or DNA probes; cofactors such as ATP, magnesium chloride, magnesium sulfate, magnesium acetate, and / or NAD(P)H; stabilizers, such as bovine serum albumin (BSA), lactose, D-mannitol and / or trehalose; electron mediator, such as potassium ferrocyanide, potassium ferricyanide, methylene blue, 1- methoxy-5-methylphenazinium methyl sulfate (MPMS) and / or ruthenium hexamine; functionalized multi-walled carbon nanotubes (MWCNTs), polyaniline (PANI) and / or functionalized gold nanoparticles to enhance the active surface area of the working electrode 130; and non-ionic surfactant, such as Tween20, and / or Triton™ X-100, to facilitate the homogeneous dispersion of reagent on the working electrode 130.

[0139] FIG. 11A illustrates a droplet 110 moving from the movement grid 104 to an electrochemical sensor 108, according to some embodiments.

[0140] Fluid transfer from the DMF grid 104 to the electrochemical sensor 108 may be accomplished by masking the chip before applying the hydrophobic coating during fabrication to create a hydrophilic cut-out that draws droplets 110 onto the electrode surface. In some embodiments, vibrational forces may be applied to move the droplet 110.

[0141] FIG. 11B illustrates the movement grid 104 and electrochemical sensors 108 with a cutout 146, according to some embodiments.

[0142] Adding a cutout 146 can reduce the chances of a bubble forming on top of the electrochemical sensor 108. Bubbles can displace sample fluid 110 which prevents good signal determination and thus preventing bubbles can be beneficial. Bubbles can also pop, for example, mid-measurement and perturb an ongoing reaction.

[0143] In some embodiments, potential advantages of bifurcating the analyzer system 300 and the chip 100 may be that the components required for controlling and carrying sample testing out can be reused while components that contact the sample or that are depleted or contaminated by sample testing can be replaced. This can enable reuse of some components (one analyzer system 300 can be reused). This can further enable compatibility with a plurality of chips 100 (e.g., different chips 100 may be configured for different test panels) that do not require expert set up or cleaning between uses (chips 100 can be manufactured such that users need not apportion reagents or clean the chips 100 during or after use).

[0144] As described above, in some embodiments, a chip 100 and an analyzer system 300 may be integral to one another without deviating from the teachings of this disclosure. For example, a system which is configured to run the provision of sample testing and the specific sample testing components may be carried out in one integral component. Such integral implementations may, for example, be configured for single uses or may be configured to be replenished or otherwise reconfigured and subsequently reused.

[0145] The systems and methods described herein can be accomplished using external devices and servers. For example, an analyzer system 300 may communicate results of testing to an external device once the testing is complete or it may receive updates or instructions from a server. The systems and methods described herein can be compatible within broader healthcare treatment solutions.

[0146] Injecting Collected Sample onto the Reservoir Electrode.

[0147] Injecting or inserting the sample onto the chip 100 can be vital to ensuring that the sample is captured by the reservoir 102 for subsequent dispensation. Furthermore, the sample may be filtered during the injection process. Such features may improve the sample retention (thus enabling reduced sample volume extractions) and enhance filtration (which may be beneficial in some embodiments). Furthermore, sample injection may be impeded by capillary lock.

[0148] FIG. 12 illustrates a blood plasma separator locking mechanism 400, according to some embodiments.

[0149] In some embodiments, a locking mechanism 400 may be used to secure the blood plasma separator 500 to, for example, ensure proper placement and to provide a straightforward means of sample injection. The blood plasma separator 500 may comprise a separation filter 502 to separate plasma from the red blood cells.

[0150] The locking mechanism 400 may include a holder 402 and a filter lock 404. The holder 402 may be fabricated by, for example, 3D printing methods. The filter lock 404 may be, for example, a mechanical filter lock. This can be used to hold the separation filter 502 in place during plasma filtration and / or sample insertion. The filter lock 404 may prevent leakage from the sides of the separation filter.

[0151] As illustrated, the chip 100 can include transfer paper 140 at the insertion point which can be sandwiched between a bottom plate and a top plate. The transfer paper 140 may include, for example, P8 grade filter paper or Whatman Fusion 5 filter paper. The bottom plate can include a hydrophobic layer 118 to repel the sample, a dielectric layer 114 to modulate the electrical forces applied to the sample (e.g., the EWOD forces), a DMF reservoir electrode to act as a reservoir 102 for the sample, and the printed circuit board for DMF 112. The top layer may include a top hydrophobic coating 119 and a conductive top plate for DMF 120.

[0152] The locking mechanism 400 may provide hydrophilic contact with the filter 140 to provide a conduit for the filtered plasma to exit the separation filter 502 using gravity and / or capillary forces. The liquid then comes in contact with a transfer paper 140 that brings the separated plasma in contact with the top hydrophobic layer 119 and bottom hydrophobic layer 118 of the DMF and establishes electrical contact with the DMF system. Following electrical contact, electrowetting can be used to draw the plasma out from the transfer paper 140 and onto the DMF.

[0153] In some embodiments, the blood plasma separator 500 may be integral to the chip 100. This may obviate the need for a locking mechanism 400.

[0154] Microfluidic Volume Partitioning.

[0155] At times it may be beneficial to partition a sample droplet 110. This may be beneficial to aliquot the sample droplet 110 or it may be beneficial to separate the sample droplet 110 (e.g., to perform a solid-liquid extraction or to remove magnetic particles from the sample droplet 110). In some embodiments, a hydrophobic cutter that is generally flat or tapered to a cutting end may be used to segment a sample droplet 110. The hydrophobic cutter may be provided on the movement grid 104 and sample droplets 110 may be controlled to pass through the hydrophobic cutter to be segmented.

[0156] In some embodiments, it may be beneficial to use a dividing apparatus that can divide aliquots precisely. In some embodiments, it may be beneficial to use a dividing apparatus that can divide aliquots smaller than the minimum movement volume of the movement grid 104 or to apply biasing (e.g., a magnetic field) to better separate solids (e.g., magnetic particles) from a liquid. For example, the execution of enzyme-linked immunosorbent assays (ELISA) can include a number of steps that require separation of a liquid phase from a solid phase such as the separation of functionalised beads from a liquid medium during target binding and subsequentwashing steps. In some embodiments, more sophisticated dividing components can be use which may be better equipped to precisely aliquot specific volume (e.g., smaller than the minimum movement volume) and / or to carry out solid-liquid extractions.

[0157] FIG. 13A is a plan view of a movement grid 104 with a divider 160 included thereon, according to some embodiments.

[0158] The divider 160 can be used to aliquot or separate a sample droplet 110. The divider 160 may comprise a dividing surface 164, a retaining area 166, and a path (collectively 162a and 162b) through the divider 160. The sample droplet 110 may be moved along an unobstructed portion of the path 162a to an obstructed portion of the path 162b constrained by the dividing surface 164. As the sample droplet 110 passes the dividing surface 164 the sample droplet 110 is divided by the dividing surface into a retained volume 110a held in the retaining area 166 and a remainder volume 110b that can continue along the obstructed portion of the path 162b. The retained volume 110a may be recoverable using the unobstructed portion of the path 162a after the remainder volume 110b moves away.

[0159] The dividing surface 164 can be a flat geometric object wherein at least a portion of the dividing surface 164 is a hydrophobic surface positioned in the gap between the DMF electrodes 106 on the bottom and a grounded cover plate on the top (or vice versa) creating an impermeable hydrophobic barrier. The divider 160 shape defines an enclosed area with at least an unobstructed portion of the path 162a and an obstructed portion of the path 162b such that a sample droplet 110 can enter or exit the divider 160 through the unobstructed portion of the paths 162a while the passage through the obstructed portion of the path 162b is constrained by a dividing surface 164. The dividing surface 164 is designed to enable cleavage of a volume defined by the retaining area 166 when the sample droplet 110 is moved through it. Importantly, the retained volume 110a can then be recovered from the retaining area 166 through the unobstructed portion of the path 162a.

[0160] FIG. 13B and FIG. 13C are plan views of movement grids 104 with alternative dividers 160 included thereon, according to some embodiments.

[0161] The divider 160 of FIG. 13B includes a retaining area 166 that is defined by a substantially concave right angle in the divider 160. The dividing surface 164 is defined by a substantially convex right angle. The sample droplet 110 will travel along the unobstructed portion of the path 162a into the retaining area 166 and then pass the obstructed portion of the path 162b.

[0162] The divider 160 of FIG. 13C includes a retaining area 166 that is defined by a substantially flared surface of the divider 160 which ends abruptly before the dividing surface 164. The dividing surface 164 is defined by a substantially right angle obstructing a portion of the path 162a that leads into the retaining area 166. The sample droplet 110 will travel along the unobstructed portion of the path 162a into the retaining area 166 and then pass the obstructed portion of the path 162b.

[0163] The above examples dividers 160 and the specific retaining area 166 and dividing surface 164 configuration of each are not limiting. Many more suitable configurations exist to partition the sample droplet 110 as it passes through the obstructed portion of the path 162b.

[0164] Some embodiments of the divider 160 include deliberate positioning of a magnetic field 168 with varying proximity and positioning in relation to the dividing surface 164 and retaining area 166 as to enable separation and subsequent recovery of magnetic particles 172 contained in the liquid phase of the sample droplet 110. The magnetic field 168 is provided by a magnetic field generator. In some embodiments, the magnetic field generator may include a permanent magnet. In some embodiments, the magnetic field generator may include a selectively activable magnet (e.g., an electromagnet). In some embodiments, the magnetic field generator may include a movable magnet. In some embodiments, the magnetic field generator may be configured to selectively move between an on-state and an off-state. In some embodiments, the magnetic field generator may be configured to selectively produce a magnetic field strength along a spectrum within a range of magnetic field strengths. In some embodiments, the magnetic field generator may be a magnet that is configured to rotate to vary the orientation of the magnetic field 168. The magnetic field generator may be a magnet 169 which can be seen in FIG. 13B and FIG. 13C. In some embodiments, the magnetic field generator may be disposed above, below, or within the cavity 126.

[0165] In some embodiments, the shape of the dividing surface 164 and the retaining area 166 are selected based, in part, on the desired volume of the sample droplet 110 to be retained in the retaining area 166. In some embodiments, the EWOD forces from the DMF electrodes 106 may in part determine the volume of the sample droplet 110 retained in the retaining area 166. In some embodiments, the retained volume 110a may be smaller than the minimum volume that can be moved on the movement grid 104.

[0166] T o aid partitioning magnetic particles 172 while allowing for their subsequent recovery in the retained volume 110a, a magnetic field 168 may be positioned in relation to the two portions of the paths 162a and 162b in such a way that the magnetic field 168 is nearly aligned with the obstructed portion of the path 162b constrained by the dividing surface 164 while at the same time is near perpendicular to the unobstructed portion of the path 162a. In this way the magnetic field 168 can act on the magnetic particles 172 to impede their passage through the obstructed portion of the path 162b. In contrast, the magnetic field 168 would have little to no effect on magnetic particle 172 movement through the unobstructed portion of the path 162a. Thus, the magnetic particles 172 can be separated from the liquid phase of the sample droplet 110, and can be recovered by resuspending the magnetic particles 172 in a liquid and transporting the magnetic particles 172 out of the divider 160 through the unobstructed portion of the path 162a.

[0167] In some embodiments, the divider 160 has a magnetic field 168 applied through at least a portion thereof which may also, in part, determine the volume of the sample droplet 110 retained in the retaining area 166. For example, the strength and orientation of the magnetic field 168 may impact the volume of the sample droplet 110 retained in the retaining area 166. The magnetic field 168 may beneficially separate any magnetic particles 172 (e.g., pre-existing magnetic particles, unreacted magnetic reagents, magnetic reaction products, magnetic mixing beads, functionalised magnetic beads (e.g., for ELISA assays), etc.) in the sample droplet 110. In some embodiments, the partitioning may be aided by magnetic particles 172 added to the sample droplet 110.

[0168] In some embodiments, the path 162a and 162b may in part be defined by the edge of one or more switched off DMF electrodes 106a (being one of or a subset of the DMF electrodes 106) which act as hydrophobic cells.

[0169] FIG. 14A is a plan view of the movement grid 104 with the divider 160 included thereon of FIG. 13A with a sample droplet 110 approaching, according to some embodiments.

[0170] The sample droplet 110 may include, for example, magnetic particles 172.

[0171] FIG. 14B is a plan view of the movement grid 104 with the divider 160 included thereon of FIG. 13A with a sample droplet 110 entering the divider 160, according to some embodiments.

[0172] The sample droplet 110 can enter the divider 160 through the unobstructed portion of the path 162a and come into contact with the dividing surface 164. The dividing surface 164 cancleave the sample droplet 110. The magnetic particles 172 can be biased into the retaining area 166, in part, with the magnetic field 168. The specific orientation of the magnetic field 168 relative to the obstructed portion of the path 162b may substantially prevent the magnetic particles 172 from exiting that way. The magnetic field 168 may assist in phase separation by concentrating the magnetic particles 172 and preventing the magnetic particles 172 from departing with the remainder volume 110b. In some embodiments, the dividing surface 164 is used to effectively decant the remainder volume 110b away from the retained volume 110a. In some embodiments, the magnetic particles 172 may require a certain amount of time to settle in the retaining area 166 before the remainder volume 110b moves on. The strength of the magnetic field 168 can affects how quickly this happens for magnetic particles 172, however too much magnetic field 168 can interfere with subsequent recovery of the magnetic particles 172.

[0173] FIG. 14C is a plan view of the movement grid 104 with the divider 160 included thereon of FIG. 13A with a remainder volume 110b leaving the divider 160, according to some embodiments.

[0174] The sample droplet 110 can be cleaved into a remainder volume 110b which may exit the divider 160 and a retained volume 110a which may be retained in the retaining area 166. The remainder volume 110b may exit the divider 160 by continuing along the dividing surface 164 obstructed portion of the path 162b. The retained volume 166 may contain all or substantially all of any magnetic particles 172 that were initially in the sample droplet 110.

[0175] FIG. 14D is a plan view of the movement grid 104 with the divider 160 included thereon of FIG. 13A with a wash droplet 174 approaching, according to some embodiments.

[0176] In some embodiments, wash droplet 174 can be used to recover the magnetic particles 172. In some embodiments, a further sample droplet 110 may be used to recover the magnetic particles 172. In some embodiments, the wash droplet 174 may be a wash buffer or other reagent.

[0177] FIG. 14E is a plan view of the movement grid 104 with the divider 160 included thereon of FIG. 13A with a wash droplet 174 entering the divider 160, according to some embodiments.

[0178] The wash droplet 174 enters the divider 160 through the unobstructed portion of the path 162a. The wash droplet 174 can envelop the magnetic particles 172 in the retaining area 166.

[0179] FIG. 14F is a plan view of the movement grid 104 with the divider 160 included thereon of FIG. 13A with a wash droplet 174 leaving the divider 160 with the magnetic particles 172, according to some embodiments.

[0180] The wash droplet 174 can exit the divider 160 through the unobstructed portion of the path 162a. The magnetic particles 172 can be retained by the wash droplet 174 as it exits because the unobstructed portion of the path 162a is not obstructed by the dividing surface 164 and / or because the magnetic field 168 does not bias the magnetic particles 172 against using that portion of the path 162a.

[0181] The minimum movable volume that can be moved on a movement grid 104 can be defined as a product of the area of an individual actuated cell of the movement grid 104 and the height of the space separating the grid and the cover plate. The divider 160 can allow partitioning of a predefined volume, that may or may not be smaller than the minimum volume that can be moved on a given movement grid 104. In the case that it is smaller, the retained volume 110a can subsequently be fully recovered by a separate carrier liquid droplet (e.g., the wash droplet 174) large enough to be transported on the movement grid 104. Generally, a divider 160 will retain the same volume of liquid of the same type of composition each time it is used.

[0182] The divider 160 described herein can be used for precise volume aliquoting. The volume retained by the retaining area 166 can be defined by the area and shape of the retaining area 166, as well as the contact angle between the dividing surface 164 and the sample droplet 110. Certain applications may use DMF as miniaturised liquid handling platforms. A suitably calibrated series of dividers 160 can enable partitioning / dispensing a comprehensive range of volumes which can make the platform more versatile. There may be no residual volume left behind in the divider 160. Thus, the aforementioned dispensing series of dividers 160 can be reused, taking on the function of a DMF-driven pipettor.

[0183] In some embodiments, the volume partitioned in the retaining area 166 can be precisely set to match the volume of solid phase magnetic particles 172 by manipulating the shape and positioning of the divider 160 and the magnetic field 168.

[0184] In some embodiments, a volume of analyte A that is smaller than the minimum movable volume can be partitioned from a bulk reservoir to be mixed with a volume of analyte B that is of equal or greater volume than the minimum volume that can be transported on a givenmovement grid 104. Importantly, the AB mixture can be fully recovered and transported to another location as needed.

[0185] In some embodiments, if analyte A contains a solid phase, functionalized magnetic particles 172, and analyte B contains a sample analyte, an on-DMF target analyte capture / recognition step can be performed.

[0186] In some embodiments, if analyte A contains the solid phase magnetic particles 172 and analyte B consists of a wash buffer, an on-DMF washing step can be performed.

[0187] In some embodiments, if analyte A contains the solid phase magnetic particles 172 and analyte B contains reporter-linked detection probe, an on-DMF target analyte detection step can be performed.

[0188] In some embodiments, if analyte A contains the solid phase functionalized magnetic particles 172 and analyte B contains a binding competitor, an on-DMF competitive binding step can be performed.

[0189] In some embodiments, functionalized magnetic particle recovery and transport to a detection compartment, such as (but not limited to) electrochemical detection cell, light detection chamber, or other mode of reporter readout, can facilitate an assay readout.

[0190] FIG. 14G-FIG. 141 show a series of plan views of a movement grid showing the retention of magnetic particles using subdivided DMF electrodes, according to some embodiments.

[0191] In some embodiments, subdivided DMF electrodes can be used in place of a physical barrier. For example, an actuated electrode can act to retain fluid containing magnetic particles 172. In such an embodiment, one or more of DMF electrodes 106 in the movement grid 104 may be subdivided into a plurality of separated DMF electrodes 106x and 106y, namely, such a DMF electrode 106 is replaced with a plurality of separated DMF electrodes 106x and 106y. DMF electrodes 106x are independently actuatable from each other and from DMF electrodes 106y. The droplet 110 may approach the separated DMF electrodes 106x and 106y (FIG. 14G) and pass onto the separated DMF electrodes 106x and 106y (FIG. 14H). The separated DMF electrodes 106x and 106y may function in manners similar to other DMF electrodes 106 disclosed herein (e.g., consisting of a unitary electrode) as the droplet 110 passes onto the separated DMF electrodes 106x and 106y (e.g., they act in concert to exhibit the behaviour of other DMFelectrodes 106) or they may operate as independent DMF electrodes to help more precisely adjust the orientation of the droplet 110. The magnet 169 may operate to apply a magnetic field to draw the magnetic particles 172 to a region of the droplet 110 above the one or more separated DMF electrodes 106y that may operate to retain a portion of the droplet 110 (e.g., retained volume 110a). Surface tension can keep the magnetic particles 172 inside the droplet 110 while the magnet 169 draws the magnetic particles 172 towards the magnet 169, but within the droplet 110. Once the droplet 110 is positioned over the separated DMF electrodes 106x and 106y, then the other DMF electrodes 106 of the movement grid 104 may operate to move the droplet off the separated DMF electrodes 106x and 106y. One or more of the separated DMF electrodes 106y may operate to retain the retained volume 110a with the magnetic particles 172 on the separated DMF electrodes 106y (namely they may continue to apply EWOD forces to the retained volume 110a). The rest of the surrounding DMF electrodes 106 and the other separated DMF electrodes 106x may move the remainder volume 110b away from the retained volume 110a. The droplet 110 can be split towards directions that face away from the site of magnetic particles 172 aggregation to ensure that no magnetic particles 172 are pulled out during the splitting (e.g., towards the bottom of FIG. 141 as illustrated).

[0192] The magnet 169 can be located outside the DMF environment. The magnetic field can influence the DMF environment and affect the magnetic particles 172 floating in the droplet 110. The magnetic field strength can be controlled by choosing the strength of the magnet 169 and the distance to the magnet 169 at which splitting occurs to ensure that the magnetic particles 172 are not irreversibly held close to the magnet 169 and can be maneuvered by moving the remainder volume 110b.

[0193] In such implementations, the divider 160 may be the separated DMF electrode 106y that holds the retained volume 110a in place as the remainder volume 110b is moved away.

[0194] As described above, the remainder volume 110b may undergo further operations or analyses. As also described above, a wash droplet 174 may subsequently be moved to the retained volume 110a to envelop the retained volume 110a to recover the magnetic particles 172 or provide a wash buffer or other reagent.

[0195] In some embodiments, if the sample droplet 110 is larger than the DMF electrodes 106 in the movement grid 104, then a DMF electrode 106 that is the same size (or sized based on the portioning needs of the sample droplet 110) can be used with a magnet 169 to draw themagnetic particles 172. In such embodiments, the magnet 169 may still operate to attract the magnetic particles 172 onto the DMF electrode 106 closest to the magnet 172 (or where drawn by an applied magnetic field) and the remaining DMF electrodes 106 may operate to cleave a remainder volume 110b away from the retained volume 110a which includes the magnetic particles 172.

[0196] Example Implementations.

[0197] According to an aspect, there is provided a device for sample analysis. The device includes a movement grid 104 and a divider 160 disposed in a cavity 126 of the movement grid 104. The movement grid 104 includes a top layer and a bottom layer. The bottom layer includes a dielectric layer 114 coated with a bottom hydrophobic layer 118. The top layer includes a conductive top plate 120 coated with a top hydrophobic layer 119. The top layer and the bottom layer define the cavity 126. A plurality of digital microfluidic (DMF) electrodes 106 are configured to selectively actuate regions of the dielectric layer 114 to move a sample droplet 110 within the cavity 126 between regions corresponding to each of the plurality of DMF electrodes 106 via electrowetting-on-dielectric forces. The divider 160 includes a path 162a and 162b for the sample droplet 110 to be moved along by the electrowetting-on-dielectric forces. The divider 160 configured to divide the sample droplet 110 into at least a retained volume 110a to be held in a retaining area 166 and a remainder volume 110b to be moved along the path 162a and 162b.

[0198] In some embodiments, the device further includes a magnetic field generator configured to selectively apply a magnetic field 168 within at least a portion of the path 162a and 162b to manipulate magnetic particles 172 within the sample droplet 110.

[0199] In some embodiments, the magnetic particles 172 are functionalized magnetic beads.

[0200] In some embodiments, the device is configured to recover and wash the magnetic particles 172 with a wash droplet 174.

[0201] In some embodiments, the magnetic field 168 is oriented to move the magnetic particles 172 into the retained volume 110a.

[0202] In some embodiments, the magnetic field 168 is applied to be substantially aligned with an outlet of the path 162b and substantially perpendicular to an inlet of the path 162a.

[0203] In some embodiments, the magnetic field 168 holds the magnetic particles 172 in the retained volume 110a and the divider 160 includes one or more separated DMF electrodes 106y that are configured to hold the retained volume 110a in place in part by electrowetting-on-dielectric forces applied by the one or more separated DMF electrodes 106y.

[0204] In some embodiments, the divider 160 includes a dividing surface 164 configured to constrain the path 162a and 162b to divide the sample droplet 110 into at least the retained volume 110a and the remainder volume 110b.

[0205] In some embodiments, the dividing surface 164 includes a hydrophobic surface positioned in a gap between two of the plurality of DMF electrodes 106.

[0206] In some embodiments, the divider 160 is configured to separate a liquid phase of the sample droplet from a substantially solid phase of the sample droplet 110.

[0207] In some embodiments, the path 162a and 162b is defined by an edge of one or more switched off DMF electrodes 106a.

[0208] In some embodiments, the size and shape of the retaining area 166 and an applied magnetic field 168 define a magnitude of the retained volume 110a for a given fluid.

[0209] Example Methods.

[0210] FIG. 15 is a flowchart of example droplet manipulation operations 1500 performed by the system 300 of FIG. 2 on the movement grid 104 of FIG. 13A, according to some embodiments.

[0211] The droplet manipulation operations 1500 of the movement grid 104 is further described with reference to the flowchart depicted in FIG. 15, in accordance with an embodiment.

[0212] As depicted, the system 300 performs example operations depicted at blocks 1502 and onward, in accordance with an embodiment.

[0213] At block 1502, a sample droplet 110 is disposed onto a movement grid 104 including a top layer and a bottom layer. The bottom layer including a dielectric layer 114 coated with a bottom hydrophobic layer 118. The top layer including a conductive top plate 120 coated with a top hydrophobic layer 119. The top layer and the bottom layer defining a cavity 126, and selectively actuatable regions of the dielectric layer 114 for moving a sample droplet 110 within the cavity 126 via electrowetting-on-dielectric forces.

[0214] At block 1504, the sample droplet 110 is moved by EWOD forces along a path 162a and 162b that includes a divider 160 that divides the sample droplet 110 into at least a retained volume 110a to be held in a retaining area 166 and a remainder volume 110b to be moved along the path 162a and 162b.

[0215] In some embodiments, the divider 160 includes a dividing surface 164 that constrains the path 162a and 162b. In some embodiments, the divider includes a separated DMF electrode 106y that holds the retained volume 110a in place.

[0216] It should be understood that steps of one or more of the blocks depicted in FIG. 15 may be performed in an interleaved or iterative manner. Further, variations of the steps, omission or substitution of various steps, or additional steps may be considered.

[0217] According to another aspect, there is provided a method 1500 of manipulating a sample droplet 110. The method 1500 includes disposing a sample droplet 110 onto a movement grid 104 (block 1502) and moving the sample droplet 110 along a path 162a and 162b by the electrowetting-on-dielectric forces (block 1504). The path includes a divider 160 that divides the sample droplet 110 into at least a retained volume 110a to be held in a retaining area 166 and a remainder volume 110b to be moved along the path 162a and 162b. The movement grid 104 includes a top layer and a bottom layer. The bottom layer includes a dielectric layer 114 coated with a bottom hydrophobic layer 118. The top layer includes a conductive top plate 120 coated with a top hydrophobic layer 119. The top layer and the bottom layer define a cavity 126 and selectively actuatable regions of the dielectric layer 114 for moving a sample droplet 110 within the cavity 126 via electrowetting-on-dielectric forces.

[0218] In some embodiments, the method 1500 includes applying a magnetic field 168 with at least a portion of the path 162a and 162b to manipulate magnetic particles 172 within the sample droplet 110.

[0219] In some embodiments, the magnetic particles 172 are functionalized magnetic beads.

[0220] In some embodiments, the method 1500 further comprises recovering and washing the magnetic particles 172 with a wash droplet 174.

[0221] In some embodiments, the magnetic field 168 is applied to be substantially aligned with an outlet of the path 162b and substantially perpendicular to an inlet of the path 162a.

[0222] In some embodiments, the magnetic field 168 is oriented to move the magnetic particles 172 into the retained volume 110a.

[0223] In some embodiments, the magnetic field 168 holds the magnetic particles 172 in the retained volume 110a and the divider 160 includes one or more separated DMF electrodes 106y that are configured to hold the retained volume 110a in place in part by electrowetting-on-dielectric forces applied by the one or more separated DMF electrodes 106y.

[0224] In some embodiments, the divider 160 includes a dividing surface 164 configured to constrain the path 162a and 162b to divide the sample droplet 110 into at least the retained volume 110a and the remainder volume 110b.

[0225] In some embodiments, the dividing surface 164 includes a hydrophobic surface positioned in a gap between at least two of the plurality of DMF electrodes 106.

[0226] In some embodiments, the method 1500 includes recovering the retained volume 110a from the divider 160.

[0227] In some embodiments, the divider 160 is configured to separate a liquid phase of the sample droplet 110 from a substantially solid phase of the sample droplet 110.

[0228] In some embodiments, the path 162a and 162b includes an edge of one or more switched off DMF electrodes 106a.

[0229] In some embodiments, the size and shape of the retaining area 166 and an applied magnetic field 168 define a magnitude of the retained volume 110a for a given fluid.

[0230] In some embodiments, the method 1500 includes moving the retained volume 110a away from the divider 160.

[0231] In some embodiments, the method 1500 includes moving an additional droplet 174 into the divider 160 to join the retained volume 110a and moving at least a portion of the joined additional droplet 174 and retained volume 110a towards an electrochemical sensor 108.

[0232] In some embodiments, the method 1500 includes moving at least a portion of the remainder volume 110b towards an electrochemical sensor 108.

[0233] Computer Implementation Details.

[0234] The embodiments of the devices, systems and methods described herein may be implemented in a combination of both hardware and software. These embodiments may be implemented on programmable computers, each computer including at least one processor, a data storage system (including volatile memory or non-volatile memory or other data storage elements or a combination thereof), and at least one communication interface.

[0235] Program code is applied to input data to perform the functions described herein and to generate output information. The output information is applied to one or more output devices. In some embodiments, the communication interface may be a network communication interface. In embodiments in which elements may be combined, the communication interface may be a software communication interface, such as those for inter-process communication. In still other embodiments, there may be a combination of communication interfaces implemented as hardware, software, and combination thereof.

[0236] Throughout the foregoing discussion, numerous references will be made regarding servers, services, interfaces, portals, platforms, or other systems formed from computing devices. It should be appreciated that the use of such terms is deemed to represent one or more computing devices having at least one processor configured to execute software instructions stored on a computer readable tangible, non-transitory medium. For example, a server can include one or more computers operating as a web server, database server, or other type of computer server in a manner to fulfill described roles, responsibilities, or functions.

[0237] The technical solution of embodiments may be in the form of a software product. The software product may be stored in a non-volatile or non-transitory storage medium, which can be a compact disk read-only memory (CD-ROM), a USB flash disk, or a removable hard disk. In some embodiments, the software product may be stored on an EEPROM on the chip 100 which can communicate with a processor on board the analyzer 300. The software product includes a number of instructions that enable a computer device (personal computer, server, or network device) to execute the methods provided by the embodiments.

[0238] The embodiments described herein are implemented by physical computer hardware, including computing devices, servers, receivers, transmitters, processors, memory, displays, and networks. The embodiments described herein provide useful physical machines and particularly configured computer hardware arrangements. The embodiments described herein are directed to electronic machines and methods implemented by electronic machines adapted for processingand transforming electromagnetic signals which represent various types of information. The embodiments described herein pervasively and integrally relate to machines, and their uses; and the embodiments described herein have no meaning or practical applicability outside their use with computer hardware, machines, and various hardware components. Substituting the physical hardware particularly configured to implement various acts for non-physical hardware, using mental steps for example, may substantially affect the way the embodiments work. Such computer hardware limitations are clearly essential elements of the embodiments described herein, and they cannot be omitted or substituted for mental means without having a material effect on the operation and structure of the embodiments described herein. The computer hardware is essential to implement the various embodiments described herein and is not merely used to perform steps expeditiously and in an efficient manner.

[0239] FIG. 16 is a schematic diagram of a computing device 1600, according to some embodiments. As depicted, computing device 1600 includes at least one processor 1602, memory 1604, at least one I / O interface 1606, and at least one network interface 1608. The computing device 1600 and aspect thereof may be provided within the user device 200 and the analyzer system 300 of FIG. 2.

[0240] For example, and without limitation, the computing device 1600 may be a server, network appliance, set-top box, embedded device, computer expansion module, personal computer, laptop, personal data assistant, cellular telephone, smartphone device, LIMPC tablets, video display terminal, gaming console, electronic reading device, and wireless hypermedia device or any other computing device capable of being configured to carry out the methods described herein.

[0241] For simplicity only one computing device 1600 is shown but system may include more computing devices 1600 operable by users to access remote network resources and exchange data. The computing devices 1600 may be the same or different types of devices. The computing device 1600 at least one processor, a data storage device (including volatile memory or nonvolatile memory or other data storage elements or a combination thereof), and at least one communication interface. The computing device components may be connected in various ways including directly coupled, indirectly coupled via a network, and distributed over a wide geographic area and connected via a network (which may be referred to as “cloud computing”).

[0242] Each processor 1602 may be, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, a programmable read-only memory (PROM), or any combination thereof.

[0243] Memory 1604 may include a suitable combination of any type of computer memory that is located either internally or externally such as, for example, random-access memory (RAM), read-only memory (ROM), compact disc read-only memory (CDROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically- erasable programmable read-only memory (EEPROM), Ferroelectric RAM (FRAM) or the like.

[0244] Each I / O interface 1606 enables computing device 1600 to interconnect with one or more input devices, such as a keyboard, mouse, camera, touch screen and a microphone, or with one or more output devices such as a display screen and a speaker.

[0245] Each network interface 1608 enables computing device 1600 to communicate with other components, to exchange data with other components, to access and connect to network resources, to serve applications, and perform other computing applications by connecting to a network (or multiple networks) capable of carrying data including the Internet, Ethernet, plain old telephone service (POTS) line, public switch telephone network (PSTN), integrated services digital network (ISDN), digital subscriber line (DSL), coaxial cable, fiber optics, satellite, mobile, wireless (e.g. Wi-Fi, WiMAX), SS7 signaling network, fixed line, local area network, wide area network, and others, including any combination of these.

[0246] Computing device 1600 is operable to register and authenticate users (using a login, unique identifier, and password for example) prior to providing access to applications, a local network, network resources, other networks and network security devices. Computing devices 1600 may serve one user or multiple users.

[0247] Implementation Details.

[0248] The following discussion provides many example embodiments. Although each embodiment represents a single combination of inventive elements, other examples may include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, other remaining combinations of A, B, C, or D, may also be used.

[0249] Although terms such as “maximize”, “minimize” and “optimize” may be used in the present disclosure, it should be understood that such terms may be used to refer to improvements, tuning and refinements which may not be strictly limited to maximal, minimal or optimal.

[0250] The term “connected” or "coupled to" may include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements).

[0251] The term “substantially” as used herein may be applied to modify any quantitative representation which could permissibly vary without resulting in a change in the basic function to which it is related. For example, a drive shaft as disclosed herein having a circular transverse cross-section may permissibly have a somewhat non-circular cross-section within the scope of the invention if its rotational driving capability is not materially altered.

[0252] Although the embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope as defined by the appended claims.

[0253] Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

[0254] As can be understood, the examples described above and illustrated are intended to be exemplary only. The scope is indicated by the appended claims.

Claims

WHAT IS CLAIMED IS:1 . A device for sample analysis, the device comprising: a movement grid comprising a top layer and a bottom layer, the bottom layer comprising a dielectric layer coated with a bottom hydrophobic layer, the top layer comprising a conductive top plate coated with a top hydrophobic layer, the top layer and the bottom layer defining a cavity, wherein a plurality of digital microfluidic (DMF) electrodes are configured to selectively actuate regions of the dielectric layer to move a sample droplet within the cavity between regions corresponding to each of the plurality of DMF electrodes via electrowetting-on-dielectric forces; a divider disposed in the cavity, the divider including a path for the sample droplet to be moved along by the electrowetting-on-dielectric forces, the divider configured to divide the sample droplet into at least: a retained volume to be held in a retaining area; and a remainder volume to be moved along the path.

2. The device of claim 1 , further comprising a magnetic field generator configured to selectively apply a magnetic field within at least a portion of the path to manipulate magnetic particles within the sample droplet.

3. The device of claim 2, wherein the magnetic particles are functionalized magnetic beads.

4. The device of claim 2, wherein the device is configured to recover and wash the magnetic particles with a wash droplet.

5. The device of claim 2, wherein the magnetic field is oriented to move the magnetic particles into the retained volume, and wherein the magnetic field is applied to be substantially aligned with an outlet of the path and substantially perpendicular to an inlet of the path.

6. The device of claim 2, wherein the magnetic field holds the magnetic particles in the retained volume and the divider comprises one or more separated DMF electrodes that are configured to hold the retained volume in place in part by electrowetting-on-dielectric forces applied by the one or more separated DMF electrodes.

7. The device of claim 1 , wherein the divider comprises a dividing surface configured to constrain the path to divide the sample droplet into at least the retained volume and the remainder volume.

8. The device of claim 7, the dividing surface includes a hydrophobic surface positioned in a gap between two of the plurality of DMF electrodes.

9. The device of claim 1 , wherein the divider is configured to separate a liquid phase of the sample droplet from a substantially solid phase of the sample droplet.

10. The device of claim 1 , wherein the path is defined by an edge of one or more switched off DMF electrodes.

11. The device of claim 1 , wherein the size and shape of the retaining area and an applied magnetic field define a magnitude of the retained volume for a given fluid.

12. A method of manipulating a sample droplet, the method comprising: disposing a sample droplet onto a movement grid comprising a top layer and a bottom layer, the bottom layer comprising a dielectric layer coated with a bottom hydrophobic layer, the top layer comprising a conductive top plate coated with a top hydrophobic layer, the top layer and the bottom layer defining a cavity, and selectively actuatable regions of the dielectric layer for moving a sample droplet within the cavity via electrowetting-on-dielectric forces; moving the sample droplet along a path by the electrowetting-on-dielectric forces, wherein the path comprises a divider that divides the sample droplet into at least: a retained volume to be held in a retaining area; and a remainder volume to be moved along the path.

13. The method of claim 12, further comprising applying a magnetic field with at least a portion of the path to manipulate magnetic particles within the sample droplet.

14. The method of claim 13, wherein the magnetic particles are functionalized magnetic beads.

15. The method of claim 13, wherein the magnetic field is applied to be substantially aligned with an outlet of the path and substantially perpendicular to an inlet of the path.

16. The method of claim 13, wherein the magnetic field holds the magnetic particles in the retained volume and the divider comprises one or more separated DMF electrodes that are configured to hold the retained volume in place in part by electrowetting-on-dielectric forces applied by the one or more separated DMF electrodes.

17. The device of claim 12, wherein the divider comprises a dividing surface configured to constrain the path to divide the sample droplet into at least the retained volume and the remainder volume.

18. The method of claim 17, the dividing surface comprises a hydrophobic surface positioned in a gap between at least two of the plurality of digital microfluidic (DMF) electrodes.

19. The method of claim 12, wherein the divider is configured to separate a liquid phase of the sample droplet from a substantially solid phase of the sample droplet.

20. The method of claim 12, further comprising at least one of: recovering the retained volume from the divider; moving the retained volume away from the divider; moving an additional droplet into the divider to join the retained volume and moving at least a portion of the joined additional droplet and retained volume towards an electrochemical sensor; and moving at least a portion of the remainder volume towards an electrochemical sensor.

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