Patent attributes
A microvalve device includes a semiconductor-based valve housing that defines a flow passage, and a valve face disposed within the valve housing and in fluid communication with the flow passage. The microvalve device further includes a thermal expansion actuator that drives movement of the valve face from a first position to a second position relative to the flow passage, and a capacitor that holds the valve face in the second position. The microvalve may also include an insulating layer disposed on portions of the semiconductor-based valve housing, and a capacitance sensor for monitoring a capacitance level to determine when the valve face reaches the second position. Once the sensor indicates that the second position has been reached, power is no longer applied to the thermal expansion actuator such that power is only substantially consumed during the transition from the first position to the second position. The thermal expansion actuator may include a heating element and a thermal expansion substance for thermopneumatic displacement of the valve face.
