| abstract |
There is disclosed herein an apparatus for converting control signals of an electrical or optical nature or any other type of signal which may be converted to a change of temperature of a fixed volume of material trapped in a chamber to flexure of a membrane forming one wall of the chamber. Typically, the device is integrated onto a silicon wafer by anisotropically etching a trench into said wafer for enough that a thin wall of silicon remains as the bottom wall of the trench. In some embodiments, polyimide is used as the material for the membrane. The trench is then hermetically sealed in any one of a number of different ways and the material to be trapped is either encapsulated during the sealing process or later placed in the cavity by use of a fill hole. Typically, a resistor pattern is etched on the face of pyrex wafer used as a top for the trench to form the cavity. When current is passed through this resistor, the material in the cavity is heated, its vapor pressure increases and expansion occurs. There is also disclosed herein a pressure regulator and a flow regulator each of which are integrated on a single die using the valve structure disclosed herein. |