Abstract: A fluid ejection device includes a fluid slot, a first fluid ejection chamber communicated with the fluid slot and including a first drop ejecting element, a second fluid ejection chamber including a second drop ejecting element, and a fluid circulation path including a first portion communicated with the fluid slot and the second fluid ejection chamber, and a second portion communicated with the first fluid ejection chamber and the second fluid ejection chamber, with the fluid circulation path including a fluid circulating element within the first portion.

Abstract: An inkjet nozzle includes an aperture with a noncircular opening having a first segment substantially defined by a first polynomial equation and a second segment substantially defined by a second equation.

Abstract: The present disclosure is drawn to microfluidic devices. A microfluidic device can include a substrate, a lid mounted to the substrate, and a microchip mounted to the substrate. The lid mounted to the substrate can form a discrete microfluidic chamber between structures including an interior surface of the lid and a portion of the substrate. The lid can include an inlet and a vent positioned relative to one another to facilitate loading of fluid to the discrete microfluidic chamber via capillary action. A portion of the microchip can be positioned within the discrete microfluidic chamber.

Abstract: In an example implementation, a method of cell lysis includes moving cell fluid from a first reservoir through a microfluidic channel toward a second reservoir, activating a lysing element multiple times as a cell from the cell fluid passes through the microfluidic channel, and moving lysate fluid that results from the activating through the microfluidic channel and into the second reservoir.

Abstract: A multizonal microfluidic device can include a substrate with multiple structures mounted thereon, including a first and second lid, and a first and second microchip. The first lid and the substrate can form a first microfluidic chamber between structures including a first interior surface of the first lid and a first discrete portion of the substrate. The first lid can include a first inlet and a first vent positioned relative to one another to facilitate loading of fluid to the first microfluidic chamber via capillary action. A portion of the first microchip can be positioned within the first microfluidic chamber. Furthermore, the second lid can be configured like the first lid and can also be mounted on the substrate forming a second microfluidic chamber with the second microchip positioned within the second microfluidic chamber.

Abstract: One example includes a device that may include a heating element and a molecular binding site. The heating element may heat a fluid volume, interfaced with the heating element, in response to a voltage being applied to the heating element, the heat transforming the fluid volume from a liquid state into a vaporized state to generate fluid motion within the fluid volume. The molecular binding site may be disposed proximate to the heating element, in which a portion of the fluid volume expands when the fluid volume transforms from the liquid state into the vaporized state, the vaporized state of the fluid volume generating the fluid motion within a target fluid that is disposed within the molecular binding site.

Abstract: An apparatus includes a microfluidic channel and a flow sensor along the microfluidic channel. The flow sensor includes a heat emitting resistor for connection to an electric current source, analytical parameter sensor and electronics. The heat emitting resistor has a resistance that varies in response to temperature. The electrical parameter sensor is to sense an electrical parameter of the heat emitting resistor that is based on the resistance of the heat emitting resistor. The electronics determine a flow based on the sensed electrical parameter.

Abstract: In an example implementation, a method of microfluidic filtering includes activating a first fluid pump within a microfluidic channel to cause a forward flow of fluid through the microfluidic channel and through a filter of a filter loop. The filter loop intersects the microfluidic channel at a loop entry and at a loop exit. The method includes activating a second fluid pump to cause a reverse flow of fluid through the filter.

Abstract: A thermal fluid ejection heating element may include a first conductive trace, and an at least partially perforated resistive thin film material electrically coupling the first conductive trace to a second conductive trace. The perforations within the perforated resistive thin film material defines a resistance of the thermal fluid ejection heating element.

Abstract: A device for microfluidic transport includes a first fluid reservoir, a second fluid reservoir spaced from the first fluid reservoir, a main fluid channel communicated with the first fluid reservoir and the second fluid reservoir, an auxiliary fluid channel communicated with the main fluid channel, and a fluid actuator within the auxiliary fluid channel asymmetric to the main fluid channel such that operation of the fluidic actuator is to induce fluid flow in the main fluid channel from the first reservoir toward the second reservoir.

Abstract: An inkjet nozzle includes an aperture with a noncircular opening substantially defined by a polynomial equation. A droplet generator is also described which includes a firing chamber fluidically coupled to a fluid reservoir a heating resistor and a nozzle. The nozzle includes an aperture forming a passage from the firing chamber to the exterior of the droplet generator through a top hat layer. The nozzle is defined by a closed polynomial and has a mathematically smooth and mathematically continuous shape around aperture's perimeter wall, with two protrusions extending into the center of the aperture.

Abstract: One example provides a microfluidic mixing device that includes a main fluidic channel to provide main fluidic channel flow and a number of I-shaped secondary channels extending outwardly from a portion of the main fluidic channel. A number of inertial pumps are located within the I-shaped secondary channels to create serpentine flows in the direction of the main fluidic channel flow or create vorticity-inducing counterflow in the main fluidic channel.

Abstract: A fluid ejection device includes a fluid slot, two laterally adjacent fluid ejection chambers each communicated with the fluid slot and having a drop ejecting element therein, and a fluid circulation path communicated with each of the two laterally adjacent fluid ejection chambers and having a fluid circulating element therein, with the two laterally adjacent fluid ejection chambers to concurrently eject drops of fluid therefrom such that the drops of fluid are to coalesce during flight.

Abstract: A droplet of fluid having a predetermined drop weight is ejected from a microfluidic channel. Electrical signals are received from a sensor in the microfluidic channel, wherein the electrical signals vary in response to the ejection of the droplet of fluid. The electrical signals of the sensor are calibrated to a rate of flow of fluid through the microfluidic channel based on a number of droplets ejected and the predetermined drop weight of each droplet.

Abstract: Examples include microfluidic devices. Example microfluidic devices comprise a first microfluidic channel, a second microfluidic channel, and microfluidic output channel fluidly coupled to the first microfluidic channel and the second microfluidic channel via a fluid junction. The example device comprises a first fluid actuator disposed in the first microfluidic channel to actuate to thereby pump a first fluid into the microfluidic output channel, and the example device comprises a second fluid actuator disposed in the second microfluidic channel to actuate to pump a second fluid into the microfluidic output channel. The first fluid actuator and the second fluid actuator are to actuate to thereby pump a fluid mixture of the first fluid and the second fluid into the microfluidic output channel.

Abstract: An immiscible droplet generation system may include a chip, a microfluidic channel integrated into the chip, an input to the microfluidic channel through which the microfluidic channel is to be filled with a first fluid that is to be moved through the microfluidic channel and a droplet generator. The droplet generator is integrated into the chip to generate a droplet of a second fluid, immiscible within the first fluid, and to inject the droplet into the first fluid in the microfluidic channel.

Abstract: A fluid ejection device includes a fluid slot, a first fluid ejection chamber communicated with the fluid slot and including a first drop ejecting element, a second fluid ejection chamber communicated with the fluid slot and including a second drop ejecting element, a fluid circulation path communicated with the first fluid ejection chamber and the second fluid ejection chamber, and a fluid circulating element within the fluid circulation path.

Abstract: Examples include a fluid ejection die embedded in a molded panel. The fluid ejection die comprises a substrate, and the substrate includes an army of nozzles extending therethrough. The substrate has a first surface in which nozzle orifices are formed and a second surface, opposite the first surface, in which nozzle inlet openings are formed. The fluid ejection die is embedded in the molded panel such that the first surface of the substrate is approximately planar with a top surface of the molded panel. The molded panel has a fluid channel formed therethrough in fluid communication with the nozzle inlet openings of the array of nozzles.

Abstract: Examples include microfluidic devices. Example microfluidic devices comprise a first microfluidic channel, a second microfluidic channel, and microfluidic output channel fluidly coupled to the first microfluidic channel and the second microfluidic channel via a fluid junction. The example device comprises a fluid actuator disposed in the microfluidic output channel to actuate to thereby pump a first fluid and a second fluid into the microfluidic output channel.

Abstract: A fluid ejection device includes a fluid slot, a first fluid ejection chamber communicated with the fluid slot and including a first drop ejecting element, a second fluid ejection chamber including a second drop ejecting element, and a fluid circulation path including a first portion communicated with the fluid slot and the second fluid ejection chamber, and a second portion communicated with the first fluid ejection chamber and the second fluid ejection chamber, with the fluid circulation path including a fluid circulating element within the first portion.