Provided herein is a method of loading wells with a liquid droplet, or a portion thereof, wherein each liquid droplet comprises solid supports and a detergent or surfactant, such that the detergent or surfactant reduces the contact angle between the liquid droplet and the wells. Also provided is a method of detecting and quantifying an analyte of interest in a sample, which involves loading wells in an array with a liquid droplet according to aforementioned method, wherein the liquid droplet comprises an analyte captured on a solid support.

Devices that may couple two or more apparatuses, such as an organ-on-a-chip device and a microfluidic device. Devices that include an organ-on-a-chip device, a microfluidic device, and a cap that couples the organ-on-a-chip device and the microfluidic device. Systems that include the devices and a detection unit. Methods for quantitation of insulin.

In biosciences and related fields, it can be useful to study cells in isolation so that cells having unique and desirable properties can be identified within a heterogenous mixture of cells. Processes and methods disclosed herein provide for encapsulating cells within a microfluidic device and assaying the encapsulated cells. Encapsulation can, among other benefits, facilitate analyses of cells that generate secretions of interest which would otherwise rapidly diffuse away or mix with the secretions of other cells.

Disclosed is a method for the cell-free expression of peptides or proteins in a liquid filled digital microfluidic device. The droplets having the components required for cell-free protein expression can be manipulated by electrokinesis in order to enhance levels of protein expression in the droplets.

Methods of selectively positioning a micro-object in a microfluidic device are described in this application. The microfluidic device can comprise an enclosure having an inlet, an outlet, and a flow region connecting the inlet and outlet, and an electrode activation substrate having a photoconductive layer. The methods of selectively positioning can comprising: projecting a first light beam on an electrode activation substrate of the microfluidic device, wherein the first position is proximal to the first micro-object, and wherein the first light beam activates a positive dielectrophoresis (DEP) force within the enclosure sufficient to capture the first micro-object; and projecting a second light beam upon a second position on the electrode activation substrate, wherein the second position is adjacent to or at least partially surrounding the first position, without overlapping the first position, the second light beam activating a positive DEP force within the enclosure sufficient to capture second micro-objects other than the first micro-object. The methods of selectively positioning can further comprise moving the first light beam towards a third position on the electrode activation substrate, wherein the DEP force activated by the first light beam is sufficient to move the first micro-object to the third position. Optionally, the methods can include moving the second light beam in relation to the first light beam to prevent micro-objects other than the first micro-object from being captured by the first light beam. Other embodiments are described.

A microfluidic system includes a hydrophobic fluidic platform and a heater. The platform includes a plurality of electrode cells operably connected to a voltage source and a controller. The heater is configured to fuse first and second vesicles. The first and second vesicles encapsulate first and second DNA precursors, respectively. The fusing combines the first and second DNA precursors. In another embodiment, a microfluidic system includes a fluidic platform including a plurality of electrode cells, a vesicle mover, and a reaction facilitator. The vesicle mover is configured to move first and second vesicles to a selected cell of the plurality of electrode cells. The reaction facilitator is operably connected to the selected cell. A method includes providing a fluidic platform comprising a plurality of cells; moving first and second vesicles encapsulating first and second reagents, respectively, to a first cell; and fusing the first and second vesicles.

Microfluidic pumps are provided that use electrowetting to manipulate the location of one or more droplets of a working fluid (e.g., water) in order to pump tears, blood, laboratory samples, carrier fluid, or some other payload fluid. The working fluid is separated from the payload fluid by one or more droplets of an isolating fluid that is immiscible with the working fluid. The working fluid is manipulated via electrowetting, by applying voltages to two or more electrodes, to repeatedly move back and forth. Forces, pressures, and/or fluid flows exerted by the working fluid are coupled to the payload fluid via the droplet(s) of isolation fluid and reed valves, diffuser nozzles, or other varieties of valve can act as flow-rectifying elements to convert the coupled forces into a net flow of the payload fluid through the pump.

The present disclosure provides a microfluidic device, including a bottom substrate, an electrowetting-on-dielectric (EWOD) chip, a circuit board, a dielectric film, and a motor. The EWOD chip is disposed on the bottom substrate, and the circuit board is arranged on the EWOD chip. The circuit board includes a circuit area that is electrically connected to the EWOD chip, and the empty area is adjacent to the circuit area and the EWOD chip is exposed. The dielectric film is disposed on the empty area of the circuit board and covers the exposed EWOD chip. The motor is disposed under the bottom substrate, and one end of the motor has a magnetic structure, so that the magnetic structure can move closer to or away from the bottom substrate.

Disclosed herein is a novel method of producing monodisperse aqueous droplets, as well as a novel microfluidic droplet generator. In some examples, the method comprises flowing an aqueous solution through a microchannel and into a sample reservoir of the microfluidic droplet generator, wherein monodisperse droplets of the aqueous solution form by step-emulsification at a step change in height at an intersection of a reservoir end of the microchannel and a sidewall of the sample reservoir. In some examples, the aqueous solution is a hydrogel precursor solution and monodisperse droplets of the hydrogel precursor solution form by step-emulsification at the step change in height at the intersection of the reservoir end of the microchannel and the sidewall of the sample reservoir. In some examples, the monodisperse droplets of the hydrogel precursor solution are incubated under conditions suitable for gelation to form hydrogel beads.

Methods are provided for separating magnetically responsive beads from a droplet in a droplet actuator. Droplet operations electrodes and a magnet are arranged in a droplet actuator to manipulate a bead-containing droplet and position it relative to a magnetic field region that attracts the magnetically responsive beads. The droplet operations electrodes are operated to control the droplet shape and transport it away from the magnetic field region to form a concentration of beads in the droplet. The continued transport of the droplet away from the magnetic field causes the concentration of beads to break away from the droplet to yield a small, concentrated bead-containing droplet immobilized by the magnet.