A micro-fluidic system comprising a micro-fluidic channel, which has a wall provided with a hole; a closing element, which is partially housed within the hole and has a membrane portion adapted to deform and a side portion sealingly connected with the above mentioned wall; and a partition arranged within the micro-fluidic channel between a first and a second segment; the closing element is deformable between a locked configuration in contact with the partition and an open configuration spaced from the partition; the closing element may be deformed by suction or by a rod or a piston.

An electronic device includes a housing and an internal pressure regulator valve. The internal pressure regulator valve includes a valve body of flexible material. The valve body has a valve hole and a hollow. The hollow is continuous with the valve hole and opens into the housing. Through the valve hole, gas is released to outside.

The invention relates to a method for making a laminated microfluidics with membrane valves. The method comprises (a) generating a membrane valve assembly comprising (1) laminating three plastic foils together, the top foil comprising one through hole for each valve, the middle foil has a slit pattern connecting each valve hole of the top foil, and the bottom foil has one through hole for each valve and one additional hole entering the slit pattern; (2) placing the laminated foil, bottom foil down on a mould half having a smooth mould surface with one or more perpendicularly protruding cylinders that concentrically fit within the through holes of the laminated foil yet leave room for a membrane to form, and clamping a second mould half to close the mould; (3) injecting and allowing to cure a liquid rubber through a funnel associated with the bottom mould half and the additional hole on the bottom foil layer; and (b) laminating the membrane valve assembly and a flow path. Also provided is a membrane valve assembly made according to the method.

High throughput screening of crystallization of a target material is accomplished by simultaneously introducing a solution of the target material into a plurality of chambers of a microfabricated fluidic device. The microfabricated fluidic device is then manipulated to vary the solution condition in the chambers, thereby simultaneously providing a large number of crystallization environments. Control over changed solution conditions may result from a variety of techniques, including but not limited to metering volumes of crystallizing agent into the chamber by volume exclusion, by entrapment of volumes of crystallizing agent determined by the dimensions of the microfabricated structure, or by cross-channel injection of sample and crystallizing agent into an array of junctions defined by intersecting orthogonal flow channels.

Microscale valves for use in, e.g., micropump devices, may be formed of a slitted diaphragm bonded o the interior of a valve tube. A bump in the diaphragm and/or a backward-leakage stopper may increase the breakdown pressure of the valve. A push-rod may be used to pre-load the valve membrane to thereby increase the cracking pressure.

High-density microfluidic chips contain plumbing networks with thousands of micromechanical valves and hundreds of individually addressable chambers. These fluidic devices are analogous to electronic integrated circuits fabricated using large scale integration (LSI). A component of these networks is the fluidic multiplexor, which is a combinatorial array of binary valve patterns that exponentially increases the processing power of a network by allowing complex fluid manipulations with a minimal number of inputs. These integrated microfluidic networks can be used to construct a variety of highly complex microfluidic devices, for example the microfluidic analog of a comparator array, and a microfluidic memory storage device resembling electronic random access memories.

A valve is provided with a tubular structure having an outer tube and an inner tube, and a diaphragm member having a thin film disposed to cover one end of the inner tube and an anchor part which encircles a peripheral edge of the thin film and comes into close contact with an inner wall of the outer tube and an outer wall of the inner tube.

Plastic microfluidic structures having a substantially rigid diaphragm that actuates between a relaxed state wherein the diaphragm sits against the surface of a substrate and an actuated state wherein the diaphragm is moved away from the substrate. As will be seen from the following description, the microfluidic structures formed with this diaphragm provide easy to manufacture and robust systems, as well readily made components such as valves and pumps.

A static fluid and a second fluid are placed into contact along a microfluidic free interface and allowed to mix by diffusion without convective flow across the interface. In accordance with one embodiment of the present invention, the fluids are static and initially positioned on either side of a closed valve structure in a microfluidic channel having a width that is tightly constrained in at least one dimension. The valve is then opened, and no-slip layers at the sides of the microfluidic channel suppress convective mixing between the two fluids along the resulting interface. Applications for microfluidic free interfaces in accordance with embodiments of the present invention include, but are not limited to, protein crystallization studies, protein solubility studies, determination of properties of fluidics systems, and a variety of biological assays such as diffusive immunoassays, substrate turnover assays, and competitive binding assays.

Plastic microfluidic structures having a substantially rigid diaphragm that actuates between a relaxed state wherein the diaphragm sits against the surface of a substrate and an actuated state wherein the diaphragm is moved away from the substrate. As will be seen from the following description, the microfluidic structures formed with this diaphragm provide easy to manufacture and robust systems, as well readily made components such as valves and pumps.