Abstract: A microfabricated device is fabricated by depositing a first metal layer on a substrate to provide a first electrode of an electrostatic actuator, depositing a first structural polymer layer over the first metal layer, depositing a second metal layer over said first structural polymer layer to form a second electrode of the electrostatic actuator, depositing an insulating layer over said first structural polymer layer, planarizing the insulating layer, etching the first structural polymer layer through the insulating layer and the second metal layer to undercut the second metal layer, providing additional pre-formed structural polymer layers, at least one of which has been previously patterned, and finally bonding the additional structural layers in the form of a stack over the planarized second insulating layer to one or more microfluidic channels. The technique can also be used to make cross over channels in devices without electrostatic actuators, in which case the metal layers can be omitted.

Abstract: A microfabricated device is fabricated by depositing a first metal layer on a substrate to provide a first electrode of an electrostatic actuator, depositing a first structural polymer layer over the first metal layer, depositing a second metal layer over said first structural polymer layer to form a second electrode of the electrostatic actuator, depositing an insulating layer over said first structural polymer layer, planarizing the insulating layer, etching the first structural polymer layer through the insulating layer and the second metal layer to undercut the second metal layer, providing additional pre-formed structural polymer layers, at least one of which has been previously patterned, and finally bonding the additional structural layers in the form of a stack over the planarized second insulating layer to one or more microfluidic channels. The technique can also be used to make cross over channels in devices without electrostatic actuators, in which case the metal layers can be omitted.

Abstract: An integrated microfluidic device has at least at least one active element controlled by pneumatic signals, and at least one electrostatic actuator integrated in the device for generating the pneumatic signals within the device from an external supply of pressure or vacuum. In one embodiment the pressure supply may be generated internally on chip using an integrated pump.

Abstract: An integrated microfluidic check valve has a first chamber having inlet and outlet ports and divided by a barrier the said inlet and outlet ports into first and second subchambers. A membrane forms a wall of the first chamber and co-operates with the barrier to selectively permit and prevent fluid flow between the inlet and outlet ports. A second chamber adjoining the first chamber and has a wall formed by the membrane. A microfluidic channel establishes fluid communication between the second chamber and the first subchamber. The membrane deflects to permit fluid flow around the barrier when the pressure in the first subchamber is lower than the pressure in the second subchamber. Two such valves can be combined into a peristaltic pump.

Abstract: A method of removing residues from an integrated device, in particular residues resulting from processing in HF vapor, is disclosed wherein the fabricated device is exposed to dry water vapor for a period of time sufficient to dissolve the residues in the dry water vapor.