Abstract: A digital droplet PCR system is described. The digital droplet PCR system comprises a microfluidic cartridge comprising: a plurality of sample droplet generators, wherein each sample droplet generator is operable to partition a PCR mixture into a plurality of aqueous droplets dispersed in a carrier liquid, and wherein at least one sample droplet generator is operable to partition a PCR mixture that is different to a PCR mixture that is partitioned by at least one other sample droplet generator; a thermocycling chamber comprising an embedded heater, an inlet configured to receive the plurality of aqueous droplets from the plurality of sample droplet generators, and an outlet; and an optical readout zone fluidly connected to the outlet of the thermocycling chamber; and a pressure actuated pump configured to couple to and cause fluid flow through the microfluidic cartridge. A method of performing digital droplet PCR is also described.

Abstract: Microfluidic systems are provided for the detection and analysis of cell systems that can include a set of reservoirs, the set of reservoirs including a reagent reservoir and an immiscible fluid reservoir, an incubation region having an inlet and an outlet, a set of independent fluidic networks, the set of independent fluidic networks including a first fluidic network and a second fluidic network that is not fluidically connected to the first fluidic network, wherein the first fluidic network (1) is fed by the set of reservoirs, (2) includes a droplet generator, and (3) connects to the inlet of the incubation region, and wherein the second fluidic network is connected to the outlet of the incubation region.

Abstract: In one example in accordance with the present disclosure, a fluorescence detection system is described. The fluorescence detection system includes a microfluidic chamber to receive a sample containing a compound to be detected. An illumination system provides an excitation light to excite fluorophores in the microfluidic chamber. An outcoupler is disposed between the illumination system and the microfluidic chamber to diffuse the excitation light to fill the microfluidic chamber. The fluorescence detection system also includes a detection system to detect fluorescence generated by the excitation of the fluorophores in the microfluidic chamber.

Abstract: A microfluidic device is described. The device comprises a reaction chamber, wherein the reaction chamber comprises at least one reaction reagent disposed on at least one inner surface of the reaction chamber. A heater is also provided. A thermally dissolvable or degradable or thermally degradable film is applied to the at least one inner surface of the reaction chamber on which the reaction reagent is disposed. Also described is a PCR apparatus and a method of performing PCR.

Abstract: An example system includes a well plate having at least one well, an array of electrodes positioned on a surface of a bottom floor of the well, and a controller to direct electrical voltage to the electrodes to generate a non-uniform electrical field. The electrical field is to direct an object in the electrical field to a target position in the well.

Abstract: In one example in accordance with the present disclosure, a cell sorting device is described. The cell sorting device includes a microfluidic channel to serially transport individual cells from a volume of cells along a flow path. A sensor disposed in the microfluidic channel distinguishes between a cell to be analyzed and waste fluid. The cell sorting device includes at least two fluid transport devices disposed within the microfluidic channel. The at least two fluid transport devices include a cell ejector to, responsive to detection of a cell to be analyzed, eject the cell to be analyzed from the cell sorting device and a waste transport device to direct the waste fluid to a waste reservoir.

Abstract: In one example in accordance with the present disclosure, a fluorescence detection system is described. The fluorescence detection system includes a microfluidic chamber to receive a sample containing a compound to be detected. The system also includes a light guide, a portion of which is adjacent the microfluidic chamber. The light guide refracts excitation light into the microfluidic chamber to excite fluorophores in the microfluidic chamber. The light guide has total internal reflection in those portions that are not adjacent the microfluidic chamber. The fluorescence detection system also includes a heating element to trigger a reaction in the microfluidic chamber, an illumination source to provide the excitation, and a detection system to detect fluorescence generated by the excitation of the fluorophores in the microfluidic chamber.

Abstract: The present disclosure is drawn to bio-ink printer components, methods of printing bio-inks, and multi-fluid live cell printing systems. In one example, a bio-ink printer component can include a bio-ink and a bio-ink ejector fluidly connected or connectable to the bio-ink. The bio-ink can include a buffer solution that is suitable for live cells, and a polymer that includes polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl sulfate, polyethylene glycol, polyester, poly(dimethylsiloxane), cellulose, polysaccharide, or a combination thereof. The bio-ink ejector can include an ejection nozzle and a thermal resistor positioned to heat the bio-ink to form a vapor bubble to eject a droplet of bio-ink from the ejection nozzle.

Abstract: A particle classification system may include a volume to contain a fluid having a suspended particle, electrodes proximate the volume to apply an electric field to rotate the suspended particle, a focused light source, a scattered light sensor to sense light from the focused light source that has scattered upon impinging the rotating suspended particle and a controller to classify the particle based at least in part upon signals from the scattered light sensor.

Abstract: An example overfill-tolerant microfluidic structure can include an inlet microfluidic channel. A sample chamber can be connected to the inlet microfluidic channel to receive liquid from the inlet microfluidic channel. A gas-permeable liquid barrier can be connected to the sample chamber and positioned to allow gas to flow out of the sample chamber. An overflow chamber can be connected to the inlet microfluidic channel. A capillary break can be positioned between the inlet microfluidic channel and the overflow chamber. The capillary break can include a narrowed opening with a smaller width than a width of the inlet microfluidic channel. In some examples, the gas-permeable liquid barrier can allow gas to flow out of the sample chamber at a pressure lower than the break pressure, and prevent liquid from flowing out of the sample chamber at the break pressure.

Abstract: A system and a method for imaging microfluidic ejectors during operation. An example provides a microscopy system, that includes a plurality of microfluidic ejectors. A mirror is disposed in a droplet path of the plurality of microfluidic ejectors, wherein the droplet path passes through an opening in the mirror. An optical system is focused on the plurality of microfluidic ejectors through the mirror, wherein the optical system comprises a camera.

Abstract: A PCR system is described. The PCR system comprises a thermocycling chamber comprising an electrode assembly configured to generate an electric field and cause reversible electrowetting of a PCR mixture within the thermocycling chamber; and an optical sensor configured to obtain optical signals from the thermocycling chamber. Also described is a method of manufacturing a PCR system and a method of performing PCR.

Abstract: A microfluidic device is described. The device comprises a flow channel; and at least one reaction chamber. The at least one reaction chamber comprises a chamber inlet connecting the at least one reaction chamber to the flow channel, a first region adjacent the chamber inlet, a second region spaced from the chamber inlet by the first region, a vent channel and a reaction reagent disposed on at least one inner surface of the second region. Also described is a PCR apparatus and a method of performing PCR.

Abstract: A microfluidic device is described. The microfluidic device comprises a reaction chamber and a temperature control module overlaying the reaction chamber. The temperature control module comprises a temperature regulating flow channel disposed between two layers and in thermal contact with the reaction chamber, and wherein at least a portion of each layer comprises an optically transparent material. Also described is a method of manufacturing a microfluidic device and a method of controlling temperature of a reaction in a microfluidic device.

Abstract: A system includes a microchannel analysis region, a first fluid actuation device, a second fluid actuation device, a sensor, and a controller. The first fluid actuation device is at a first end of the microchannel analysis region. The second fluid actuation device is at a second end of the microchannel analysis region opposite to the first end. The sensor is within the microchannel analysis region between the first fluid actuation device and the second fluid actuation device. The sensor measures an impedance of a fluid within the microchannel analysis region. The controller activates the first fluid actuation device to generate a first pressure wave in the fluid and activates the second fluid actuation device to generate a second pressure wave in the fluid. The first pressure wave and the second pressure wave converge at the sensor.

Abstract: A droplet PCR system is described herein. The droplet PCR system comprises a chamber having a heating surface, a droplet dispenser to dispense PCR-reagent-containing droplets into the chamber, a heater disposed onto the heating surface of the chamber to heat a layer of fluid adjacent the heating surface, and a controller to control the heater to produce a pulsed heat flux.

Abstract: An image formation device includes a support, a fluid ejection device, and a first porous element. The support is to support movement of a substrate along a travel path, while the fluid ejection device is located along the travel path to deposit droplets of ink particles within a liquid carrier onto the substrate to at least partially form an image on the substrate. The first porous element is located downstream along the travel path from the fluid ejection device to be in contact against the substrate to remove, via electroosmotic flow through the first porous element, at least a portion of the liquid carrier from the substrate.

Abstract: In example implementations, an apparatus is provided. The apparatus includes a dielectrophoresis (DEP) separator, an electrical field generator, a tracking system, and a controller. The DEP separator is to separate a plurality of different particles. The electrical field generator is coupled to the DEP separator to apply a frequency to the DEP separator. The tracking system is to track a movement of a type of particles in the DEP separator. The controller is in communication with the electrical field generator to control the frequency and the tracking system to track the separation. The controller is to calculate a cross-over frequency from a cross-over frequency distribution for the type of particles based on a frequency sweep performed on the type of particles and the movement of the type of particles that is tracked.

Abstract: An example apparatus comprises includes a first reservoir to store a biologic sample containing a cell, a microfluidic channel fluidically coupled to the first reservoir, and circuitry. The microfluidic channel includes a constriction region including a first circumference that is attenuated from remaining portions of the microfluidic channel, and a fluidic pump disposed within the microfluidic channel. The circuitry is to activate the fluidic pump to direct flow of the cell from the first reservoir to the microfluidic channel and through the constriction region.

Abstract: A microfluidic system may comprise a dispense head with multiple dispensers, each dispensing a different cell type, such as single pairs of individual target cells and individual sensor cells. Interaction between the cells may be observed based on, for example, fluorescence. Individual target cells may then be selected, based on observations, for use or for further investigation. As an example, target cells may be B-cells, and enhanced selection of B-cells aids more direct antibody discovery.