Abstract: An example apparatus comprises a first microfluidic channel fluidically coupled to a first reservoir containing a carrier fluid, the first microfluidic channel including a reaction region, a fluid droplet generator, and a fluid ejector fluidically coupled to the first microfluidic channel and disposed downstream from the reaction region of the first microfluidic channel. The fluid droplet generator includes a portion of the first microfluidic channel and a second microfluidic channel that intersects the first microfluidic channel and is fluidically coupled to a second reservoir containing a reaction fluid, where the reaction fluid including a plurality of cells and fluorescently-labeled capture reagents to form reaction products with a target molecule secreted by the plurality of cells.

Abstract: An example system includes an input channel having a first end and a second end to receive particles through the first end, a sensor to categorize particles in the input channel into one of at least two categories, and at least two output channels. Each output channel is coupled to the second end of the input channel to receive particles from the input channel, and each output channel is associated with at least one category of the at least two categories. Each output channel has a corresponding pump operable, based on the categorization of a detected particle in a category associated with a different output channel, to selectively slow, stop, or reverse a flow of particles into the output channel from the input channel.

Abstract: The present disclosure is drawn to inertial pumps. An inertial pump can include a microfluidic channel, a fluid actuator located in the microfluidic channel, and a check valve located in the microfluidic channel. The check valve can include a moveable valve clement, a narrowed channel segment located upstream of the moveable valve element, and a blocking element formed in the microfluidic channel downstream of the moveable valve element. The narrowed channel segment can have a width less than a width of the moveable valve element so that the moveable valve element can block fluid flow through the check valve when the moveable valve element is positioned in the narrowed channel segment. The blocking element can be configured such that the blocking element constrains the moveable valve element within the check valve while also allowing fluid flow when the moveable valve element is positioned against the blocking element.

Abstract: The present invention relates to a method for referencing a near-field measurement, e.g. in a scanning probe microscope.

Abstract: An example system includes an input channel having a first end and a second end to receive particles through the first end, a sensor to categorize particles in the input channel into one of at least two categories, and at least two output channels Each output channel is coupled to the second end of the input channel to receive particles from the input channel, and each output channel is associated with at least one category of the at least two categories. Each output channel has a corresponding pump operable, based on the categorization of a detected particle in a category associated with a different output channel, to selectively slow, stop, or reverse a flow of particles into the output channel from the input channel.

Abstract: The present disclosure is drawn to inertial pumps. An inertial pump can include a microfluidic channel, a fluid actuator located in the microfluidic channel, and a check valve located in the microfluidic channel. The check valve can include a moveable valve element, a narrowed channel segment located upstream of the moveable valve element, and a blocking element formed in the microfluidic channel downstream of the moveable valve element. The narrowed channel segment can have a width less than a width of the moveable valve element so that the moveable valve element can block fluid flow through the check valve when the moveable valve element is positioned in the narrowed channel segment. The blocking element can be configured such that the blocking element constrains the moveable valve element within the check valve while also allowing fluid flow when the moveable valve element is positioned against the blocking element.

Abstract: Examples relate to techniques for performing a nucleic acid amplification reaction. The method includes generating a nucleic acid solution comprising a plurality of nucleic acid molecules, and combining the nucleic acid solution with a plurality of chamber particles. Each chamber particle includes a chamber for receiving the nucleic acid solution, wherein the chamber receives, at most, one of the plurality of nucleic acid molecules. Each chamber particle also includes reagents for causing a polymerase chain reaction within the chamber. The method further includes inducing nucleic acid amplification to generate an amplified nucleic acid, and performing a detection process to detect the presence of the amplified nucleic acid within the chamber.

Abstract: In example implementations, an apparatus is provided. The apparatus includes a channel, a reagent chamber, a synthetic jet channel, and an energy source. The channel is to hold a cell. The reagent chamber is coupled to the channel and stores a reagent. The synthetic jet channel is coupled to the channel and the reagent chamber. The energy source is located in the synthetic jet channel to heat a liquid in the synthetic jet channel to create a synthetic jet that carries the reagent through towards the cell to inject the reagent into the cell.

Abstract: In one example in accordance with the present disclosure, a microfluidic device is described. The microfluidic device includes a reservoir to contain a first thermally expandable fluid, a first heater to heat the thermally expandable fluid in the reservoir, a channel extending from the reservoir and connected to the reservoir at a first opening, and a liquid volume obstructing the channel.

Abstract: An example method for measuring deformability of a cell, consistent with the present disclosure, includes detecting a single cell of a biologic sample in a cell probing chamber of a microfluidic device. The method includes isolating the cell in the cell probing chamber of the microfluidic device by terminating the flow of the biologic sample through the microfluidic device. The method further includes causing deformation of the cell by introducing ultrasonic waves into the cell probing chamber, and measuring deformability of the cell responsive to the introduction of the ultrasonic waves.

Abstract: A method of alignment and fusion of cells with an electrical field includes firing a first fluid dispenser of an electrofusion device until a first impedance sensor in a first microfluidic channel of the electrofusion device detects a presence of a first cell. The method includes firing a second fluid dispenser of the electrofusion device until a second impedance sensor in a second microfluidic channel of the electrofusion device detects a presence of a second cell. The method includes moving the first cell and the second cell into a merging chamber of the electrofusion device by firing a third fluid dispenser of the electrofusion device, in response to alignment of the first cell in the first microfluidic channel with the second cell in the second microfluidic channel. The method further includes fusing the first cell and the second cell in the merging chamber by creating an electrical field in the merging chamber.

Abstract: The present disclosure is drawn to microfluidic devices. The microfluidic device includes a microfluidic well, a layered composite stack, and an optical sensor. The layered composite stack includes an optical filter composited with an etch-stopping layer. The optical filter defines the microfluidic well. The optical sensor is associated with the microfluidic well and has the optical filter positioned therebetween.

Abstract: A fluid-ejection element of a fluid-ejection device includes a chamber layer having a pair of chambers fluidically disconnected from one another within the chamber layer. The fluid-ejection element includes a tophat layer over the chamber layer and fluidically connecting the chambers to define a fluid recirculation path between the chambers. The fluid-ejection element includes a nozzle common to both the chambers.

Abstract: Fluid is continuously recirculated through a thermal fluid-ejection printhead. Prior to firing a thermal resistor of the printhead to thermally eject a drop of the fluid through a nozzle of the printhead, the fluid is recirculated on-demand through a chamber of the printhead between the nozzle and the thermal resistor. The thermal resistor is fired to thermally eject the drop of the fluid through the nozzle. The fluid has a concentration of solids greater than 12% by volume.

Abstract: An example microfluidic device comprises a plurality of fluidic channels and a fluidic multiplexor. The fluidic multiplexor includes a plurality of fluidic micro-valves fluidically coupled to the plurality of fluidic channels, and a plurality of control lines that cross the plurality of fluidic channels proximal to the plurality of fluidic micro-valves.

Abstract: An example apparatus comprises a thermal cell lysis chamber, including a substrate and a lid coupled to the substrate to form a microfluidic channel therethrough. The apparatus includes cell detection circuitry to detect presence of a cell within the microfluidic channel and to detect lysis of the cell. The apparatus also includes a thermal lysing element disposed in the lid to apply heat to a cell detected by the cell detection circuitry, and lysis control circuitry. The lysis control circuitry is to regulate a temperature applied by the thermal lysing element, based on detection by the cell detection circuitry of a cell within the microfluidic channel and based on detection by the cell detection circuitry of a lysis event, and record the temperature applied by the thermal lysing element at which the lysis event occurred.

Abstract: An example device includes a droplet ejector including a nozzle to eject droplets of a fluid and a target medium to receive the droplets of the fluid. The target medium is separated from the droplet ejector by a gap to be traversed by the droplets. The example device further includes a frame affixing the target medium to the droplet ejector. The target medium is immovably held with respect to the droplet ejector.

Abstract: An example device includes a microfluidic channel and a movable element retained in the microfluidic channel to move from a first position to a second position by fluid flow through the microfluidic channel. The device includes a sensor to take a sensor reading to determine fluid flow through the microfluidic channel. The device includes a microfluidic pump to return the movable element from the second position to the first position. The device includes a controller to actuate the microfluidic pump and to determine a flow rate of the fluid flow through the microfluidic channel based on the sensor reading.

Abstract: In example implementations, an apparatus is provided. The apparatus includes a channel, an opening in the channel, and a heating element aligned with the opening on opposite sides of the channel. The channel contains a droplet of a first liquid containing a particle, wherein the droplet is carried within a second liquid in the channel. The heating element is to heat the first liquid to generate a vapor in the first liquid to eject the droplet of the first liquid through the opening.

Abstract: A microfluidic reaction chamber with a reaction chamber circuit includes a microfluidic reaction chamber to contain a reaction fluid for amplification of nucleic acids, and a reaction chamber circuit disposed within the microfluidic reaction chamber. The microfluidic reaction chamber includes a base wall, a top wall parallel to the base wall and defined in part by a transparent lid, a first side wall, and a second side wall. The reaction chamber circuit is disposed within the microfluidic reaction chamber, and includes a top surface, a bottom surface, a first side wall, and a second side wall. The reaction chamber circuit is in fluidic contact with the reaction fluid and includes a photodetector to detect a fluorescence signal from a labeled fluorescent tag in the reaction fluid.