A droplet dispensing apparatus includes a droplet ejection device, a microplate holder, a sheet stand, an image capturing device and a controller. The image capturing device is configured to move to a position above the sheet stand. The controller is configured to perform image processing on image data generated from an image captured by the image capturing device when the image capturing device is at the position above the test sheet on the sheet stand, to determine a size of each of test patterns formed by droplets dropped on the test sheet from the array of nozzles. The controller is further configured to generate a data file including the determined size of each of the test patterns. The test sheet colors or discolors at a place receiving a light-transmissive droplet.

A droplet dispensing apparatus includes a droplet ejection device, a microplate holder, a sheet stand, an image capturing device and a controller. The image capturing device is configured to move to a position above the sheet stand. The controller is configured to perform image processing on image data generated from an image captured by the image capturing device when the image capturing device is at the position above the test sheet on the sheet stand, to determine a size of each of test patterns formed by droplets dropped on the test sheet from the array of nozzles. The controller is further configured to generate a data file including the determined size of each of the test patterns. The test sheet colors or discolors at a place receiving a light-transmissive droplet.

In example implementations, a method is provided. The method may be executed by a processor of a fluid dispensing apparatus. The method includes storing a correction factor for an unqualified fluid. A request to dispense the unqualified fluid is received. A dispense parameter is adjusted in accordance with the correction factor. Then, the unqualified fluid is dispensed in accordance with the dispense parameter that is adjusted.

A droplet dispensing apparatus includes a crystal sensor, a resonance frequency measuring unit, and a controller. The controller is configured to obtain the resonance frequency of the crystal sensor before droplets are discharged from a liquid dropping device, control the liquid dropping device to discharge droplets on to the crystal sensor, and obtain the resonance frequency of the crystal sensor after droplets are discharged from the liquid dropping device. The controller estimates a volatilization amount for the droplets on the crystal sensor based on a temporal change trend in the resonance frequency of the crystal sensor and calculates the total weight of the droplets discharged from the liquid dropping device based on the difference in resonance frequency of the crystal sensor before and after the droplets are discharged and the estimated volatilization amount.

Systems and methods for positive dispense verification are disclosed. In one embodiment, a system has a plurality of light emitters. The light from the emitters is directed toward a plurality of light detectors across a proximately horizontal plane. The liquid dispense device is positioned above the horizontal plane of light emission from the plurality of light emitters to the plurality of light detectors such that the dispensed liquid will travel through the horizontal plane defined by the emitted light and onto the container being inoculated. Each of the plurality of detectors is coupled to an amplifier. The amplifier generates a signal in response to an interrupt in the transmission of light from the light emitters to the light detectors when the light path is disrupted by the dispense of liquid confirming the liquid was dispensed onto the container.

A dropper dispenser comprising: a fluid reservoir (1) including at least one movable wall (11) so as to put the fluid in the reservoir (1) under pressure; a cannula (24) having an outlet (25) that is designed to form a drop of fluid; and a valve (3) that is arranged between the reservoir (1) and the cannula (24) so as to control firstly the flow of fluid from the reservoir (1) into the cannula (24), and secondly the flow of fluid, and possibly air, from the cannula (24) into the reservoir (1), the valve (3), when subjected to sufficient pressure from the fluid in the reservoir (1), defining an opening (33) having a flow section that is proportional to the force exerted on the movable wall (11) of the reservoir (1); the dropper dispenser being characterized in that it further comprises a valve-opening limiter (27) so as to limit the opening (33) of the valve (3) while fluid is flowing from the reservoir (1) into the cannula (24), so as to create additional head loss that reduces the flow of fluid through the cannula (24).

The invention provides methods for assessing one or more predetermined characteristics or properties of a microfluidic droplet within a microfluidic channel, and regulating one or more fluid flow rates within that channel to selectively alter the predetermined microdroplet characteristic or property using a feedback control.

A microfluidic device performs a method of partitioning droplets from a fluid reservoir containing particles that provides a non-Poissonian distribution of dispensed droplets containing a desired number of particles. Using an electrowetting on dielectric (EWOD) device, droplets are dispensed having a Poissonian distribution of dispensed droplets containing a desired number of particles, and the droplets are interrogated to determine whether each dispensed droplet has a desired number of particles. Droplets that contain the desired number of particles are moved by EWOD operation to a reaction area on the EWOD device, and droplets that do not contain the desired number of particles are rejected and moved by EWOD operation to a holding area on the EWOD device that is different and spaced apart from the reaction area. The result is that droplets in the reaction area have a non-Poissonian distribution of droplets containing the desired number of particles.

A microfluidic device may include a microstructure formed in a substrate, the microstructure including a primary channel with a first end and a second end, and a plurality of chambers that open to the primary channel. At least two openings coupled to the first end of the primary channel may be used to load at least two fluid streams into the device through the first end of the primary channel to flow along the primary channel from the first end to the second end into the plurality of chambers, each chamber of the plurality of chambers having a volume less than 100 nanoliters and connected by a vent to a secondary channel in the micro structure, a width of the vent configured to enable a gas to escape from the chamber to the secondary channel while inhibiting the flow of said at least first and second fluid streams into the secondary channel.

An electro-wetting-based microfluidic droplet positioning system, includes an electro-wetter, a microprocessor, a main control module, a droplet drive module, a droplet positioning module and a power supply. Further, an electrowetting-based microfluidic droplet positioning method, includes the steps of: considering, by a system, a droplet to be measured in an electro-wetter and a hydrophobic insulation layer below the droplet as a capacitor connected in series; issuing, by a main control chip, a command to a droplet drive module, and driving, by the droplet drive module, the droplet to be measured to move; collecting, by a droplet positioning module, a current capacitance value of the droplet, and determining a relative position of the droplet; and verifying, by the system, whether the droplet is at a target position.