Microvalve with pressure equalization

A method of using the pressure of a fluid to provide a microvalve that is capable of operating at high pressure, the method comprising the steps of:

• providing a housing having a first layer, a second layer, a third layer, an inlet and an outlet;
• placing the inlet in fluid communication with the outlet via a passage between the inlet and outlet;
• providing a slider in the second layer of the housing;
• displacing the slider in a plane defined by the second layer to open and close the microvalve;
• directing fluid at a lower face of the slider in a direction which has at least a component which is perpendicular to the lower face of the slider;
• directing fluid at an upper face of the slider which is opposite of the lower face and in a direction which has at least a component which is perpendicular to the upper face, wherein fluid pressure on the upper and lower faces on the slider is substantially equalized.

microvalve for controlling flow of a fluid and comprising:

• a body having a first layer, a second layer overlaying the first layer, a third layer overlaying the second layer, an inlet, an outlet, and a channel interconnecting the inlet and outlet;
• a flow controller at least partially positioned within the channel and having a first face that contacts fluid entering the channel from the inlet and a second face opposite the first face;
• an actuator for moving the flow controller in the body in a plane defined by the second layer;
• a first pressure-equalizing contour formed in the body and communicating with the first face of the flow controller;
• and
• a second pressure-equalizing contour formed in the body and communicating with the second face of the flow controller, such that fluid filling the first and second pressure-equalizing contours provides pressure equalizing force on the first and second faces, respectively.