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: 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.

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 electrowetting on dielectric (EWOD) device includes an EWOD device array that applies electrowetting forces and contains a non-polar fluid. A barrier droplet configuration is formed using electrowetting forces to obstruct migration of a species from a first area of the EWOD device array to a protected area of the EWOD device array. A method of operating the EWOD device includes the steps of: dispensing a source droplet into a first area of the EWOD device array, the source droplet containing a migrating species, wherein the EWOD device array includes a second area to be protected from the migrating species; and forming a barrier droplet configuration positioned between the first area and the second area of the EWOD device array that obstructs a migration pathway of the migrating species between the first area and the second area.

Abstract: A microfluidic system includes: an electro-wetting on dielectric (EWOD) cartridge having an element array configured to receive liquid droplets, the element array including individual array elements each including array element circuity comprising sensing circuitry that is integrated into the array element circuitry; a microfluidic instrument that is configured to receive the EWOD cartridge and having an electrically conductive locator that is external to the EWOD cartridge; and a control system configured perform electrowetting operations by controlling actuation voltages applied to the element array to perform manipulation operations as to liquid droplets present on the element array. The control system further is configured to read an output from the sensing circuitry, determine a position of the locator relative to the element array based on the output, and determine a misalignment of the EWOD cartridge relative to the microfluidic instrument based on the position of the locator.

Abstract: An active matrix electro-wetting on dielectric (AM-EWOD) device has an optically black array element structure to enhance optical detection of constituents within a liquid droplet. The AM-EWOD device includes a thin film transistor (TFT) substrate assembly having a hydrophobic layer; thin film electronics having a plurality of array elements arranged in an array of rows and columns, each of the array elements including an array element electrode and a TFT device; and an optically black material disposed between a plane of the TFT device and the hydrophobic layer. The TFT substrate assembly further includes a planarization structure that includes a component having the optically black material. The planarization structure has a planarization component disposed between the TFT device and the array element electrode, and an ionic barrier disposed between the array element electrode and the hydrophobic coating. The planarization component or the ionic barrier includes the optically black material.

Abstract: An EWOD device for processing multiple droplets through multiple temperature zones. The device is configured to achieve a high spatial density of temperature zones with a wide temperature difference between hot and cold zones. A first set of temperature control elements is arranged above (or below) a fluid gap in an EWOD device and a second set of temperature control elements is arranged below (or above) the fluid gap. A temperature control element of one set is offset from temperature control elements of the other set in the plane of the fluid gap. The temperature control element of one set may be located at a different separation from the fluid gap to the temperature control element of the other set. The device has an optional temperature control element and/or arrangement which offsets the low temperature point from the inlet temperature. The two sets of temperature control elements are substantially interacting, in the sense that they cannot be considered to be thermally isolated from one another.

Abstract: An impedance cytometry device is described along with methods of accurately measuring particle size of particles contained in a fluid that is passed through the impedance cytometry device. The impedance cytometry device includes a substrate, and an electrode arrangement deposited on the substrate in a co-planar fashion. The electrode arrangement includes a drive electrode and a plurality of measurement electrodes located in a same plane as the drive electrode. The plurality of measurement electrodes includes at least two pairs of measurement sub-electrodes, each pair of measurement sub-electrodes including a first measurement sub-electrode positioned adjacent to the drive electrode, and a second measurement sub-electrode separated from the drive electrode by a respective first measurement sub-electrode.

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 that applies actuation voltages to the element and reference electrodes, and impedance sensor circuitry that senses impedance at the array element electrode to determine a droplet property at the array element. At least one component of the impedance sensor circuitry is a shared component that is shared between more than one of the array elements. The shared component may include a shared sensor readout transistor that passes a sensor current to a sensor output line, or a shared reset transistor that applies a reset voltage to a gate of the shared sensor readout transistor, with such components being shared by array elements in adjacent rows.

Abstract: A method of driving an active matrix electro-wetting on dielectric (AM-EWOD) device comprises (i) setting a reference electrode to a first reference voltage; (ii) writing a set of data to array element electrodes of array elements of the device; and (iii) either (a) maintaining the voltages written to the array element electrodes until a time t0 or (b) re-writing the set of data N?1 times (where N?2). The reference electrode is then set to a second reference voltage different from the first reference voltage, and features (i) to (iii) are repeated. When the data are first written, there is a delay between the time when the voltage on the reference electrode is transitioned and the time when a given array element is next written with data.

Abstract: An electrowetting on dielectric (EWOD) device includes a first substrate assembly and a second substrate assembly spaced apart to define a channel between them; an input port in fluid communication with the channel, the input port defining an input well for receiving a fluid for inputting into the channel; and a control port in fluid communication with the channel, the control port defining a control well for receiving a fluid and having a seal that seals the control port in a sealed state in which fluid is restricted from entering the control well from the channel. When the seal is pierced, the control port is placed in an unsealed state permitting fluid to enter the control well from the channel. The electrowetting force may be manipulated to remove the dispensed droplets via an exit port. Multiple cycles of fluid input/droplet manipulation/fluid extraction may be repeated to perform complex reaction protocols.

Abstract: A microfluidic system is configured for enhanced temperature control by combining spatial and temporal temperature control. The microfluidic system includes an electro-wetting on dielectric (EWOD) device comprising an element array configured to receive one or more liquid droplets, the element array comprising a plurality of individual array elements; a control system configured to control actuation voltages applied to the element array to perform manipulation operations of the liquid droplets; and a plurality of thermal control elements located at different spatial locations along the EWOD device, at least one of the thermal control elements being variable in temperature with respect to time. The control system includes a thermal control unit configured to control temperatures of the thermal control elements to generate a plurality of thermal zones located at different spatial locations along the EWOD device, at least one of the thermal zones being variable in temperature with respect to time.

Abstract: A method of extracting assay fluid from an EWOD device, the EWOD device comprising two opposing substrates defining a fluid space there between and an aperture for extraction of fluid from the fluid space. The method comprises providing, in the fluid space of the EWOD device, a droplet of assay fluid adjacent to the aperture such that the droplet blocks extraction, via the aperture, of filler fluid contained in the fluid space of the EWOD device, and extracting, via the aperture, at least some of the assay fluid of the droplet from the fluid space. The method comprises, during the extracting, controlling the assay fluid droplet by electrowetting to maintain the blocking of extraction of filler fluid. By controlling the position of the unextracted portion of the assay fluid droplet relative to the aperture during the extraction process, the unextracted portion of the assay fluid droplet continues to block extraction of filler fluid.

Abstract: A method of driving an element of an active matrix electro-wetting on dielectric (AM-EWOD) device comprise applying a first alternating voltage to a reference electrode of the AM-EWOD device; and either (i) applying to the element electrode a second alternating voltage that has the same frequency as the first alternating voltage and that is out of phase with the first alternating voltage or (ii) holding the element electrode in a high impedance state. The effect of applying the second alternating voltage to the element electrode is to put the element in an actuated state in which the element is configured to actuate any liquid droplet present in the element, while the effect of holding the element electrode in the high impedance state is to put the element in a non-actuated state.

Abstract: A fluid loader is provided for loading fluid into a microfluidic device, the microfluidic device having upper and lower spaced apart substrates defining a fluid chamber therebetween and an aperture for receiving fluid into the fluid chamber. The fluid loader includes a fluid well communicating with a fluid exit provided in a base of the fluid loader. The base of the fluid loader is shaped, in use, to locate the fluid loader relative to the aperture, and to direct fluid leaving the fluid loader via the fluid exit preferentially in a first direction in the fluid chamber of the microfluidic device. In one embodiment the base of the fluid loader includes a protruding portion having at least first and second legs, the first leg being shorter than the second leg. In use, the fluid loader is positioned such that the first leg of the fluid loader is between a fluid loading area associated with the aperture and an operating area of the device.

Abstract: An AM-EWOD device comprises: first and second substrates (72,36); first and second array element electrodes (38A, 38B) disposed on the first substrate (72) and defining first and second array elements in the AM-EWOD device; a reference electrode (28) disposed on the first substrate (72); a sensor; and a reference electrode drive circuit (50). The reference electrode drive circuit (50) is configured to drive the reference electrode with a first voltage waveform for actuating an array element or with a second voltage waveform different from the first voltage waveform when performing a sensing operation.

Abstract: A pixel circuit acts as a sensing element in a sensing device. The pixel circuit includes a sensing electrode, a first gate electrically connected to the sensing electrode, a second gate in electrical communication with the first gate, and a readout device that is electrically connected to the second gate. An input voltage applied to the sensing electrode is amplified between the first gate and the second gate, the amplification being measured as an output signal from the readout device to perform a sensing operation. For example, the output signal may be relatable to pH, analyte measurements, or other properties of sample liquids analyzed by the sensing device. A sensing device may include multiple pixels disposed on a substrate, each pixel including said pixel circuit. Driver circuits controlled by control electronics are configured to generate signals that selectively address the pixels and to read out voltages at the sensing electrodes.

Abstract: An active matrix electro-wetting on dielectric (AM-EWOD) device includes a plurality of array elements arranged in an array, each array element including array element circuitry, an element electrode, and a reference electrode. The array element circuitry includes an actuation circuit configured to apply actuation voltages to the electrodes, and an impedance sensor circuit configured to sense impedance at the array element electrode to determine a droplet property. The actuation circuitry includes a memory capacitor for storing voltage data corresponding to either an actuated state or an unactuated state of the array element, and an input applied to the memory capacitor operates to effect an operation of the impedance sensor circuit. Such input may isolate the array element from the actuation voltage during operation of the impedance sensor circuit, and the memory capacitor may operate as part of the impedance sensor circuit as a reference capacitor for determining the droplet property.

Abstract: An EWOD device includes a first and second substrate assemblies, and a spacer that spaces apart the first substrate assembly from the second substrate assembly to define a channel between them. The spacer defines fluid input ports that are in fluid communication with the channel, and the spacer is configured for directing fluid from the fluid input ports into the channel. The spacer has a combed spacer configuration to define the fluid input ports, including alternating teeth that extend into the channel from a base region, and the teeth isolate adjacent fluid input ports from each other. The spacer may contact only a portion of the first and second substrate assemblies to form a spacerless region within the EWOD device, and the spacer includes regions that are in contact with both the first and second substrate assemblies and extend into the channel to define a cell-gap of the channel.

Abstract: An EWOD device includes opposing substrates defining a gap and each including an insulating surface facing the gap. Array elements include electrode elements to which actuation voltages are applied. A pre-charging structure defines a channel in fluid communication with the gap wherein the channel receives an input of a fluid reservoir for generation of the liquid droplet, and the pre-charging structure includes an electrical element electrically exposed to the channel. The electrical element pre-charges the fluid reservoir within the channel, and a portion of the gap containing the liquid droplet spaced apart from the channel is electrically isolated from the electrical element such that the liquid droplet is at a floating electrical potential when located within said portion of the gap. The electrical element may be an electrode portion that is exposed to the channel, or an externally connected pre-charging element inserted into the channel.