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.

A venous valve model includes a first layer having a central axis and a fluid channel extending between a fluid inlet and a fluid outlet formed in the first layer, wherein the fluid channel is defined by a pair of channel walls, a first venous valve formed in the first layer and positioned along the fluid channel, and a pair of first actuation chambers positioned adjacent the channel walls of the fluid channel, wherein the pair of first actuation chambers are configured to decrease a width of the fluid channel in response to pressurization of the pair of first actuation chambers.

A fluidic device comprises a first channel conduit, a valve apparatus, and an additional element adjacent to the first channel conduit. The first channel conduit transports fluid from a first fluid entrance to a fluid exit. In one embodiment, the additional element is a pump chamber that receives fluid from a second fluid entrance and pumps fluid into the first channel conduit in accordance with fluid pressure. Alternatively, the additional elements include a second channel conduit and a neck of the first channel conduit. The first channel conduit and the second channel conduit share a common wall. Fluid pressure in the first channel conduit controls a valve apparatus. The value apparatus controls a rate of fluid flow in the first channel conduit by deforming the common wall to change a cross-sectional area of the neck, which changes a rate of fluid flow in the second channel conduit.

A microfluidic device comprises an inlet port for liquid, and a capillary channel in fluid connection to the inlet port for receiving liquid from the inlet port, the channel having a defined volume. At least one dissolvable valve is provided comprising a dissolvable membrane having a first side oriented towards the capillary channel, and a capillary connected to the second side of the dissolvable membrane such that when the membrane is dissolved by the liquid, liquid is transported through the valve to the second side of the membrane by capillary action. A method of controlling a flow of liquid uses such a microfluidic device.

An implantable body fluid drainage system includes a metering shunt having a housing with an internal chamber. A movable barrier divides the chamber into a first section and a second section, and the barrier can be displaced by a differential pressure. A first powered inlet valve providing a fill path to the first section of the chamber, and a first powered drain valve providing a drain path from the first section of the chamber. A CSF inlet conduit connects a CSF space to the first powered inlet valve. A CSF outlet conduit connects the first powered outlet valve to a discharge location. A controller opens the first powered inlet valve and close the first powered drain valve to fill the first section to a volume defined by the barrier and chamber geometry and closes the first powered inlet valve and opens the first powered drain valve to discharge the filled volume from the first section through the outlet conduit.

An example fluidic micro electromechanical system may include a substrate and a first layer supported by the substrate. The first layer forms sides of a chamber, a passage through one of the sides and a chamber and a check valve leaf. The check valve leaf is pivotable about an axis nonparallel to the substrate to open and close the passage. The system may further include a second layer over the chamber, an opening into the chamber and a resistor supported within the chamber.

A sodium-cooled nuclear reactor includes at least one electromagnetic pump assembly and a backflow reduction pipe. The backflow reduction pipe may include an inlet, an outlet, at least one tubular section having a first length and a first diameter, and at least one fluid diode section between the inlet and the outlet.

A fluid transportation device includes a valve cover, a valve body, a valve membrane and a valve chamber seat. The valve cover has two openings. The valve body includes an inlet passage and an outlet passage. The valve membrane is arranged between the valve body and the valve chamber seat, having two valve plates respectively close an inlet valve channel and an outlet valve channel of the valve chamber seat. The valve chamber seat forms a pressure chamber which is sealed and covered by an actuator. The valve cover is sleeved on the valve body and tightly fitted to the inner wall of an outer sleeve to assemble the device, in which a first gasket is disposed between the valve body and the valve membrane, and a second gasket is disposed between the valve membrane and the valve chamber, by which sealing effect is improved and backflow is prevented.

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 check-valve comprises: a thin sheet and a thick sheet; flow paths for flowing fluid which are formed by penetrating the thin sheet and the thick sheet; a flow-in chamber and a flow-out chamber which are connected to the flow paths; a partition sheet which is bonded to the thin sheet and the thick sheet while being sandwiched therebetween, and has a flexible inner flange which projects in cavities of the flow-in chamber and the flow-out chamber and does not close the flow-out valve chamber by flexing toward the flow-out valve chamber in a normal flow, and closes the flow-in valve chamber by flexing toward the flow-in valve chamber in a reverse flow; and a through-pass hole which is opened at the partition sheet and connects the both valve chambers.