A fluidic, device controls fluid flow in channel from a source to a drain. In some embodiments, the fluidic device comprises a channel and a gate. The channel is configured to transport a fluid from the source to the drain. The gate controls a rate of fluid flow in the channel in accordance with the fluid pressure within the gate. Specifically, the gate is configured to induce a first flow rate of the fluid in the channel in accordance with a low pressure state of the gate, and a second flow rate of the fluid in the channel in accordance with a high pressure state of the gate. In certain embodiments, the first flow rate is greater than the second flow rate. In alternative embodiments, the second flow rate is greater than the first flow rate.

An apparatus and associated method, for controlling signal passage, includes a first passageway for a first fluid, a second passageway for a second fluid, and an interposed chamber. A first, movable diaphragm at a first chamber junction and a second, movable diaphragm at a second chamber junction, with a third fluid bound there between and interposed between the first and second passageways. A device varies a volume of the third fluid bound between the diaphragms and thus moves the diaphragms. A movable member and a reservoir of the device are configured such that the movable member is sufficiently movable to increase the volume of the reservoir to remove a sufficient portion of the third fluid bound between the first and second diaphragms from the chamber to cause the first and second diaphragms to be pressed against the first and second walls, respectively.

An apparatus, for controlling signal passage, includes a first passageway for a first fluid, a second passageway for a second fluid, and an interposed chamber. A first, movable diaphragm at a first chamber junction and a second, movable diaphragm at a second chamber junction, with a third fluid bound there between and interposed between the first and second passageways. A device varies a volume of the third fluid bound between the diaphragms and thus moves the diaphragms. The diaphragms each have at least one position that permits passage of a pressure signal between the first fluid in the first passageway and the second fluid in the second passageway through the third fluid bound between the diaphragms. The diaphragms each have at least one position that prohibits passage of a pressure signal.

An apparatus, for controlling signal passage, includes a first passageway for a first fluid, a second passageway for a second fluid, and an interposed chamber. A first, movable diaphragm at a first chamber junction and a second, movable diaphragm at a second chamber junction, with a third fluid bound there between and interposed between the first and second passageways. A device varies a volume of the third fluid bound between the diaphragms and thus moves the diaphragms. The diaphragms each have at least one position that permits passage of a pressure signal between the first fluid in the first passageway and the second fluid in the second passageway through the third fluid bound between the diaphragms. The diaphragms each have at least one position that prohibits passage of a pressure signal.

A fluidic transistor comprising: a flow region configured to transport a first fluid; a gate region configured to contain a second fluid; and a deformable region disposed between the flow and gate regions, wherein the deformable region is configured to induce flow-limitation as the first fluid is transported within the flow region.

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 pressure-driven valve is disclosed. The valve includes a housing, a fluid flow channel, and a deflectable portion. The housing comprises a fluid inlet and a fluid outlet. The fluid flow channel extends between the fluid inlet and the fluid outlet. The deflectable portion is disposed within the housing, and defines a portion of the fluid flow channel. The deflectable portion is configured to deflect to increase and decrease a size of the fluid flow channel to regulate fluid flow from the fluid inlet to the fluid outlet. The deflectable portion is disposed and arranged to deflect as a result of pressure differentials between a reference pressure, a fluid flow channel pressure, and an outlet pressure representative of fluid pressure at the fluid outlet.

A microfabricated fluidic unidirectional valve includes a microfabricated elastomer material having a flow through channel. The microfabricated fluidic unidirectional valve also includes an elastomer flap attached to the elastomer material in the flow through channel. The elastomer flap forms a seal in the flow through channel to prevent fluid from flowing in a first direction through the flow through channel and to allow fluid flow in a second direction through the flow through channel.

A microfabricated fluidic unidirectional valve includes a microfabricated elastomer material having a flow through channel. The microfabricated fluidic unidirectional valve also includes an elastomer flap attached to the elastomer material in the flow through channel. The elastomer flap forms a seal in the flow through channel to prevent fluid from flowing in a first direction through the flow through channel and to allow fluid flow in a second direction through the flow through channel.

A pressure-driven valve is disclosed. The valve includes a housing, a fluid flow channel, and a deflectable portion. The housing comprises a fluid inlet and a fluid outlet. The fluid flow channel extends between the fluid inlet and the fluid outlet. The deflectable portion is disposed within the housing, and defines a portion of the fluid flow channel. The deflectable portion is configured to deflect to increase and decrease a size of the fluid flow channel to regulate fluid flow from the fluid inlet to the fluid outlet. The deflectable portion is disposed and arranged to deflect as a result of pressure differentials between a reference pressure, a fluid flow channel pressure, and an outlet pressure representative of fluid pressure at the fluid outlet.