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: 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: 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: 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: 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: An electrowetting on dielectric (EWOD) device and a related method of performing a digital biological assay in an EWOD device are described.

Abstract: A method of performing a digital quantification of a species in an electrowetting on dielectric (EWOD) device comprising the steps of: inputting a sample volume into the EWOD device; inputting 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 within the EWOD device; measuring a turn-on value for the sample droplet; comparing the measured turn-on value of the sample droplet to a target turn-on value for digital quantification; calculating a dilution factor based on the comparison of the measured turn-on value of the sample droplet to the target turn-on value; 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 in accordance with the dilution factor to form a diluted second sample droplet; and performing a digital quanti

Abstract: A microfluidic system includes an electrowetting on dielectric (EWOD) device comprising an array of elements that are actuatable for manipulation of a liquid droplet within the EWOD device. The system has a pattern generator that generates an actuation pattern for actuating a portion of the elements in the array of elements, and a signal generator that generates voltage signals for actuating elements in the array of elements in accordance with the actuation pattern. The pattern generator generates an actuation pattern in which voltage signals applied to elements in at least part of a region at or adjacent to a contact line of the droplet are different from voltage signals applied to elements that are not in the part of the region at or adjacent to the contact line. The system further may include a sensor for sensing the droplet contact line constituting a boundary of the liquid droplet.

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: 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 microfluidic system includes an electrowetting on dielectric (EWOD) device comprising an array of elements that are actuatable for manipulation of a liquid droplet within the EWOD device. The system has a pattern generator that generates an actuation pattern for actuating a portion of the elements in the array of elements, and a signal generator that generates voltage signals for actuating elements in the array of elements in accordance with the actuation pattern. The pattern generator generates an actuation pattern in which voltage signals applied to elements in at least part of a region at or adjacent to a contact line of the droplet are different from voltage signals applied to elements that are not in the part of the region at or adjacent to the contact line. The system further may include a sensor for sensing the droplet contact line constituting a boundary of the liquid droplet.

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 electrowetting on dielectric device includes: (a) a first substrate comprising electrodes at a surface of the first substrate configured to effect electrowetting mediated droplet operations; (b) a second substrate spaced from the surface of the first substrate to define an interior volume between the first substrate and the second substrate; (c) a liquid droplet disposed in the interior volume; and (d) a filler fluid disposed in the interior volume and surrounding the liquid droplet, wherein one or both of the liquid droplet and filler fluid contains a surfactant, the surfactant comprising a siloxane group represented by the structural formula: where n?1.

Abstract: An integrated microfluidic device for carrying out a series of fluidic operations includes a housing including a plurality of n microfluidic conduits, wherein n is at least three, and a rotating valve having an internal channel with an entrance port and an exit port that are angularly separated. The rotating valve is positionable in a first position to connect two of the n fluidic conduits via the internal channel, and upon rotating the valve to a second position, two other of the n fluidic conduits are connected by the internal channel. The device further may include one or more fluidic chambers in fluid communication with respective fluidic conduits. Fluid contained in one fluidic chamber is transferrable by application of positive or negative gas pressure through associated fluidic conduits into another fluidic chamber via the internal channel. The device may be utilized to perform a variety of fluidic operations.

Abstract: An integrated microfluidic device for carrying out a series of fluidic operations includes a housing including a plurality of n microfluidic conduits, wherein n is at least three, and a rotating valve having an internal channel with an entrance port and an exit port that are angularly separated. The rotating valve is positionable in a first position to connect two of the n fluidic conduits via the internal channel, and upon rotating the valve to a second position, two other of the n fluidic conduits are connected by the internal channel. The device further may include one or more fluidic chambers in fluid communication with respective fluidic conduits. Fluid contained in one fluidic chamber is transferrable by application of positive or negative gas pressure through associated fluidic conduits into another fluidic chamber via the internal channel. The device may be utilized to perform a variety of fluidic operations.

Abstract: An integrated microfluidic device for carrying out a series of fluidic operations includes a housing including a plurality of n microfluidic conduits, wherein n is at least three, and a rotating valve having an internal channel with an entrance port and an exit port that are angularly separated. The rotating valve is positionable in a first position to connect two of the n fluidic conduits via the internal channel, and upon rotating the valve to a second position, two other of the n fluidic conduits are connected by the internal channel. The device further may include one or more fluidic chambers in fluid communication with respective fluidic conduits. Fluid contained in one fluidic chamber is transferrable by application of positive or negative gas pressure through associated fluidic conduits into another fluidic chamber via the internal channel. The device may be utilized to perform a variety of fluidic operations.

Abstract: An integrated fluidic device comprising includes an input chamber that provides an input of a sample fluid, and a first overspill chamber in fluid communication with the input chamber. A metering conduit is in fluid communication with the fluid input chamber and the first overspill chamber. The metering conduit meters a first metered volume of fluid from the sample fluid, and the first overspill chamber receives fluid in excess of the first metered volume of fluid. A second overspill chamber is in fluid communication with the metering conduit. The metering conduit meters a second metered volume of fluid from the first metered volume of fluid, and the second overspill chamber receives fluid from the first metered volume of fluid in excess of the second metered volume of fluid. The second overspill chamber has a fluid actuated closable valve for controlling the metering of the second metered volume of fluid.

Abstract: An integrated fluidic device comprising includes an input chamber that provides an input of a sample fluid, and a first overspill chamber in fluid communication with the input chamber. A metering conduit is in fluid communication with the fluid input chamber and the first overspill chamber. The metering conduit meters a first metered volume of fluid from the sample fluid, and the first overspill chamber receives fluid in excess of the first metered volume of fluid. A second overspill chamber is in fluid communication with the metering conduit. The metering conduit meters a second metered volume of fluid from the first metered volume of fluid, and the second overspill chamber receives fluid from the first metered volume of fluid in excess of the second metered volume of fluid. The second overspill chamber has a fluid actuated closable valve for controlling the metering of the second metered volume of fluid.