Abstract: A microfluidic device comprises upper and lower spaced apart substrates defining a fluid chamber therebetween; an aperture for introducing fluid into the fluid chamber; and a fluid input structure disposed over the upper substrate and having a fluid well for receiving fluid from a fluid applicator inserted into the fluid well. The fluid well communicates with a fluid exit provided in a base of the fluid input structure, the fluid exit being adjacent the aperture. The fluid well comprises first, second and third portions, with the first portion of the well forming a reservoir for a filler fluid; and the second portion of the well being configured to sealingly engage against an outer surface of a fluid applicator inserted into the fluid well. The third portion of the well communicates with the fluid exit and has a diameter at the interface between the third portion and the second portion that is greater than the diameter of the second portion at the interface between the third portion and the second portion.

Abstract: A method of determining the result of an assay in a microfluidic device includes the steps of: dispensing a sample droplet onto a first portion of an electrode array of the microfluidic device; dispensing a reagent droplet onto a second portion of the electrode array of the microfluidic device; controlling actuation voltages applied to the electrode array to mix the sample droplet and the reagent droplet into a product droplet; sensing a dynamic property of the product droplet; and determining an assay of the sample droplet based on the sensed dynamic property. The dynamic property is a physical property of the product droplet that influences a transport property of the product droplet on the electrode array. Example dynamic properties of the product droplet include the moveable state, split-able state, and viscosity based on droplet properties. The method may be used to perform an amoebocyte lysate (LAL) assay.

Abstract: A microfluidic system and related methods of operating an electrowetting on dielectric (EWOD) device operate to concentrate particles within a liquid droplet dispensed onto an element array of the EWOD device. The method includes the steps of providing a non-polar liquid onto the element array of the EWOD device; providing a polar liquid droplet onto the element array of the EWOD device within the non-polar liquid, wherein the polar liquid droplet includes particles; and applying an actuation cycle comprising a plurality of actuation patterns, wherein at least one of the actuation patterns includes actuating one or more array element electrodes within a perimeter of the polar liquid droplet, and the particles migrate within the polar liquid droplet to become concentrated within a portion of the liquid droplet at one or more array element electrodes corresponding to one of the plurality of actuation patterns.

Abstract: A microfluidic device comprises upper and lower spaced apart substrates defining a fluid chamber therebetween; an aperture for introducing fluid into the fluid chamber; a plurality of independently addressable array elements, each array element defining a respective region of the fluid chamber; and control means for addressing the array elements. The control means are configured to: determine that a working fluid has been introduced into a first region of the fluid chamber; and provide an output to a user to indicate that the working fluid is present in the first region. Once the working fluid is in the first region, the fluid applicator used to dispense the fluid can be removed without any risk of accidentally withdrawing dispensed working fluid from the microfluidic device.

Abstract: A method of operating an electrowetting on dielectric (EWOD) device performs electrowetting operations on fluids dispensed into the EWOD device, which provides enhanced operation for using multiple non-polar filler fluids.

Abstract: Provided is a microfluidic device that, as compared with a conventional microfluidic device, (i) is smoother in surface of a water-repellent layer provided above a segment electrode and (ii) makes it easier for microfluid provided in the surface of the water-repellent layer to slide. A microfluidic device (1) includes: an array substrate (10) including a plurality of electrodes (14); and a counter substrate (40) including at least one electrode (42), the array substrate (10) and the counter substrate (40) having therebetween an internal space (50) in which to cause an electroconductive droplet (51) to move across the plurality of electrodes (14), and the plurality of electrodes (14) being provided on a first flattening resin layer (13) and each being a light-blocking metal electrode.

Abstract: A microfluidic control system for controlling an EWOD device has an enhanced thermal control system for generating a temperature profile within an EWOD device that is inserted into the microfluidic control system. The microfluidic control system includes a housing that defines an aperture for receiving an EWOD device; an active heating component located within the housing at a base of the aperture; and a lid attached to the housing that is moveable between a closed position and an open position, the lid including a thermal control component. When the lid is in the closed position, the thermal control component is positioned at the aperture and aligned oppositely from the active heating component. The active heating component may include a plurality of independently controllable individual heating elements, and the thermal control component may include a respective plurality of individual thermal control elements.

Abstract: A method of operating an electrowetting on dielectric (EWOD) device performs microfluidic diffusion separation.

Abstract: A control method and related apparatus are disclosed for controlling actuation voltages applied to array elements of an element array on an electrowetting on dielectric (EWOD) device, wherein test metrics are determined and employed for optimizing subsequent droplet manipulation operations. The control method includes the steps of: receiving a liquid droplet onto the element array; applying an electrowetting actuation pattern of actuation voltages to actuate the droplet to modify a footprint of the droplet from a first state having an initial footprint to a second state having a modified footprint; sensing the modified footprint with a sensor; determining a test metric from sensing the modified footprint indicative of one or more droplet properties based on a droplet response of the liquid droplet to the electrowetting actuation pattern; and controlling actuation voltages applied to the array elements based on the test metric.

Abstract: An EWOD device and a related method of performing a digital biological assay are described that employs two volume measurements for enhanced assay determination. The method includes partitioning a sample reservoir and measuring the volume of each partition; initiating a biological assay wherein the biological assay includes measuring a partition property and a volume of each partition in real time as part of determining a concentration of the product substance in each partition based on the measured partition property and volume; and categorizing the partitions by a number of biological entities contained in each partition from which the number of biological entities may be calculated, which in turn may be used to calculate the total number of biological entities or concentration in the sample reservoir. The method further may include an enhanced partitioning process that minimizes variation in the volume of the partitions.

Abstract: A method of digital quantification of a species in an EWOD device includes inputting a sample volume and a diluent volume into the EWOD device; performing an electrowetting operation to generate a first sample droplet from the sample volume; performing an amplification process on the first sample droplet and measuring a turn-on value for the sample droplet; comparing the measured turn-on value to a target turn-on value for digital quantification; calculating a dilution factor based on the comparison of the measured and target turn-on values; performing an electrowetting operation to extract a second sample droplet from the sample volume; performing an electrowetting operation to dilute the second sample droplet with the diluent volume by the dilution factor to form a diluted second sample droplet; and performing a digital quantification on the diluted second sample droplet to quantify an initial concentration of the species in the sample volume.

Abstract: A method of partitioning droplets from a fluid reservoir containing particles provides a non-Poissonian distribution of dispensed droplets containing a desired number of particles.

Abstract: A method of determining the result of an assay in a microfluidic device includes the steps of: dispensing a sample droplet onto a first portion of an electrode array of the microfluidic device; dispensing a reagent droplet onto a second portion of the electrode array of the microfluidic device; controlling actuation voltages applied to the electrode array to mix the sample droplet and the reagent droplet into a product droplet; sensing a dynamic property of the product droplet; and determining an assay of the sample droplet based on the sensed dynamic property. The dynamic property is a physical property of the product droplet that influences a transport property of the product droplet on the electrode array. Example dynamic properties of the product droplet include the moveable state, split-able state, and viscosity based on droplet properties. The method may be used to perform an amoebocyte lysate (LAL) assay.

Abstract: An embodiment of the present invention provides a microfluidic device into which fluid can be more easily introduced. A microfluidic device (1) is configured such that: (i) an upper substrate (2) is bonded to a lower substrate (6) via a sealing pattern (5) in such a manner that at least a portion of an edge of the upper substrate (2) is located inward of an edge of the lower substrate (6); and (ii) the sealing pattern (5) includes at least one gap (12) that is provided at a position where the edge of the upper substrate (2) is located inward of the edge of the lower substrate (6).

Abstract: An EWOD device includes a first substrate assembly and a second substrate assembly; wherein one of said substrate assemblies includes electrowetting electrodes, and the first substrate assembly and the second substrate assembly are spaced apart to define a channel between the substrate assemblies; and a housing for receiving the first substrate assembly and the second substrate assembly, the housing comprising an alignment feature for locating at least one of the first and second substrate assemblies within the housing. The device further includes a fixing feature for fixing the first and second substrate assemblies within the housing. The second substrate assembly is located within the housing such that the second substrate assembly is an outer component of the EWOD device. The device further may include a spacer that spaces apart the first substrate assembly from the second substrate assembly to define the channel between the first and second substrate assemblies.

Abstract: An AM-EWOD device includes a plurality of array elements arranged in an array of rows and columns, each of the array elements including array element circuitry, an element electrode, and a reference electrode. The array element circuitry includes actuation circuitry configured to apply actuation voltages to the element and/or reference electrodes for actuating the array element, and impedance sensor circuitry configured to sense impedance at the array element electrode to determine a droplet or device property at the array element, the impedance sensor circuitry comprising a sensor capacitor and a sensor readout transistor that outputs an output current for sensing. The sensor capacitor is electrically connected to a gate of the sensor readout transistor such that during a sensing phase a voltage perturbation is coupled through the sensor capacitor (and possibly other circuit elements) to the gate of the sensor readout transistor.

Abstract: A method of operating an active matrix electro-wetting on dielectric (AM-EWOD) device provides for enhanced mutual capacitance sensing using integrated impedance sensing circuitry. Array element circuitry of each array element includes actuation circuitry configured to apply actuation voltages to the array element electrode for actuating the array element, and impedance sensor circuitry integrated into the array element circuitry and configured to sense impedance at the array element electrode. The method of operating includes the steps of: perturbing a voltage applied to the array element electrode of a first array element; coupling the voltage perturbation to the array element electrode of a second array element different from the first array element; and measuring the output current from the sensor readout transistor of the second array element for sensing in response to the voltage perturbation.

Abstract: An AM-EWOD device includes a plurality of array elements arranged in an array of rows and columns; each column including a column addressing line that applies control signals to a corresponding column of array elements, and each row including a row addressing line that applies control signals to a corresponding row of array elements; each array element including an element electrode for receiving an actuation voltage and a switch transistor, wherein the switch transistor is electrically connected between the column addressing line and the element electrode and is switched by the row addressing line; and a column detection circuit comprising an addressing circuit that applies an electrical perturbation during a sensing operation to the column addressing line of an array element being sensed, and a measuring circuit that measures an output signal from one of the column addressing lines, wherein the output signal varies based upon a capacitance present at the element electrode.

Abstract: An EWOD device includes a first substrate assembly and a second substrate assembly; wherein one of said substrate assemblies includes electrowetting electrodes, and the first substrate assembly and the second substrate assembly are spaced apart to define a channel between the substrate assemblies; and a housing for receiving the first substrate assembly and the second substrate assembly, the housing comprising an alignment feature for locating at least one of the first and second substrate assemblies within the housing. The device further includes a fixing feature for fixing the first and second substrate assemblies within the housing. The second substrate assembly is located within the housing such that the second substrate assembly is an outer component of the EWOD device. The device further may include a spacer that spaces apart the first substrate assembly from the second substrate assembly to define the channel between the first and second substrate assemblies.

Abstract: A microfluidic AM-EWOD device and a method of filling such a device are provided. The device comprises a chamber having one or more inlet ports. The device is configured, when the chamber contains a metered volume of a filler fluid that partially fills the chamber, preferentially maintain the metered volume of the filler fluid in a part of the chamber. The device is configured to allow displacement of some of the filler fluid from the part of the chamber when a volume of an assay fluid introduced into one of the one or more inlet ports enters the part of the chamber, thereby causing a volume of a venting fluid to vent from the chamber.