Microfluidic structures and methods for manipulating fluids, fluid components, and reactions are provided. In one aspect, such structures and methods can allow production of droplets of a precise volume, which can be stored/maintained at precise regions of the device. In another aspect, microfluidic structures and methods described herein are designed for containing and positioning components in an arrangement such that the components can be manipulated and then tracked even after manipulation. For example, cells may be constrained in an arrangement in microfluidic structures described herein to facilitate tracking during their growth and/or after they multiply.

The disclosure relates to an arrangement (100) in a capillary driven fluid system for metering a predetermined volume of sample fluid. The arrangement comprises a sample reservoir (SR) arranged to receive a sample fluid, a first channel (C1) which is in fluid communication with the sample reservoir (SR) and which branches off into a second channel (C2) ending at a first valve (V1) and a third channel (C3) ending at a second valve (V2). The second channel (C2) and the third channel (C3) together have a predetermined volume, and the first channel (C1) is arranged to draw sample fluid from the sample reservoir (SR) by use of capillary forces to fill the second channel (C2) and the third channel (C3) with the predetermined volume of sample fluid. By selectively opening the first valve (V1) and the second valve (V2), a capillary driven flow may be formed, thereby causing the predetermined volume of sample fluid to flow out through the first valve (V1).

There is disclosed a capillary microfluidic circuit including a main channel communicating with a flow inducing element. The main channel has intermediary inlets. Reservoirs for containing one or more liquids prior to being drawn into the main channel. The reservoirs include a first reservoir and at least a second reservoir. Each of the reservoirs has an upstream end connectable to vents for filling the reservoirs with the one or more liquids and a downstream end. The downstream end of each of the reservoirs is connected to the intermediary inlets of the main channel A conduit is disposed between the first reservoir and the a least a second reservoir. The conduit links the downstream end of the first reservoir with the upstream end of the at least a second reservoir.

The disclosure describes an integrated fluid sample test strip comprising: an inlet for receiving solutions comprising a fluid sample and a substrate solution, the inlet comprising a retention valve for temporarily retaining each solution to thereby reduce air flow through the valve; a reaction chamber to receive the solutions via the retention valve, the chamber functionalized with bioreceptor(s); a capillary pump to receive from the reaction chamber the solution(s), the pump comprising vent hole(s); a test chamber to receive the substrate solution from the reaction chamber, the test chamber comprising test electrodes for a biosensing test of the substrate solution; a hydrophobic vent hole coupled to the test chamber to allow a flow of solution from the reaction chamber into the test chamber when the vent hole is unsealed and to allow a flow of solution from the reaction chamber to the capillary pump when the vent hole is sealed.

A diagnostic system for determining the presence of a target in a sample liquid that includes a diagnostic reader and a microfluidic strip having a microfluidic channel network therein. An actuator within the reader modifies the pressure of a gas in gaseous communication with a liquid-gas interface of a sample liquid within the microfluidic channel network to move and/or mix the sample liquid. The pressure modifications may be continuous and/or oscillatory.

Described herein is a microfluidic chip comprising a first channel in fluid communication with an adjacent second channel through a opening, wherein the height of the first channel and the second channel are chosen to generate sufficient surface tension at the opening such that a liquid injected into the first channel or the second channel is substantially confined within the first channel or the second channel, respectively, or that flow of the liquid therebetween is controlled, the surface tension producing a non-physical microfluidic barrier that limits or selectively controls passage of the liquid. Also described are in vitro microphysiological systems that use such microfluidic chips in modeling the structure and functions of human organs, such as a blood-brain barrier, and studying in vivo-like physiological responses of such organs to various investigative or therapeutic agents.

Embodiments of the present disclosure are directed to methods, systems and devices, for precise and reduced spot-size capabilities using a laser to alter surfaces without chemical treatment, chemical waste, or chemical residues is provided for microfluidic systems (e.g., lab-on-a-disk, for example). In some embodiments, hydrophobic and super-hydrophilic areas can be created on surfaces in the same material at different areas and positions merely by using different laser settings (e.g., spot size, wavelength, spacing, and/or pulse duration). Accordingly, capillary forces that are a recurrent issue in a microfluidic devices (e.g., a centrifugal microfluidic disk) can be controlled for practical applications, including, for example when users handle the disks and insert a sample, the moment the substrate/device (e.g., disk) is placed in a system (e.g., a centrifugal system), capillary forces can take place and move the fluids, which becomes a problem for sequential bioassays taking place in substrate/device (e.g., disk). Thus, in some embodiments, the systems, devices and methods increase fluid control in microfluidic devices.

Microfluidic device comprising at least one cell culture unit for forming, culturing, growing and/or maintaining a 3D tissue structure such as a 3D strip of cardiac tissue, wherein the at least one cell culture unit comprises: a respective culture chamber for culturing cells having a chamber outlet opening; and a cell supply channel arranged to guide a microfluidic flow of liquid holding cells between a channel inlet and a channel outlet, wherein the cell supply channel is provided with a flow inhibitor which is operable to selectively provide a flow inhibiting state or a flow permitting state depending on a fluid pressure at the flow inhibitor, wherein, in the flow inhibiting state, the flow inhibitor is configured to substantially inhibit liquid flow between the cell supply channel and the culture chamber, wherein, in the flow permitting state, the flow inhibitor is configured to permit such liquid flow such that the cell supply channel is in liquid communication with the culture chamber to supply the culture chamber with cells, wherein the culture chamber is provided with at least two mutually spaced apart elastic support structures which extend in the culture chamber and which are configured for elastically supporting a tissue formed in the culture chamber, in particular a cultured 3D tissue formed from the cells, wherein the elastic support structures are elastically deformable, in particular flexible, in particular to vary a mutual distance of said support structures under influence of a varying contraction force between said support structures.

An embodiment for a microfluidic device is provided. The device comprises two areas, arranged side-by-side, and a trigger channel. They include a first area, which is delimited by a first liquid pinning barrier, and a second area, which is delimited by a second liquid pinning barrier. The latter extends parallel to the first liquid pinning barrier to delimit a corridor. The trigger channel extends through the corridor between the two areas. In addition, the trigger channel connects the first liquid pinning barrier with the second liquid pinning barrier, allowing a first liquid pinned at the first liquid pinning barrier and a second liquid pinned at the second liquid pinning barrier to be contacted, each, by a reverse flow of the second liquid in the trigger channel and thereby start mixing at a level of the corridor, in operation. The invention is further directed to related methods of operation.

A device for dispensing one or more microdroplets is provided. The device comprising a microfluidic chip having an oEWOD structure configured to create an optically-mediated electrowetting (oEWOD) force, the microfluidic chip includes a first region and a second region, wherein said first and second regions are separated by a constriction; wherein the first region is adapted to receive and manipulate one or more microdroplets dispersed in a carrier fluid at first flow rate; and wherein the second region is configured to receive the microdroplet via the constriction from the first region and transfer said microdroplet to an outlet port of the microfluidic chip in a second flow rate; wherein the second region is configured to receive said microdroplet via the constriction from the first region by application of an optically -mediated electrowetting (oEWOD) force; and wherein the second flow rate in the second region is higher than the first flow rate in the first flow region. A method and apparatus for dispensing one or more microdroplets are also provided.