Integrated, microminiature electric to fluidic valve

US4824073A · kind A · utility

Assignee

• Stanford University · US

Inventor

• Mark Zdeblick · Portola Valley, US

Key dates

• Filing date: Sep 24, 1986
• Grant date: Apr 25, 1989
• Expiry date: Sep 24, 2006

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16K2099/009
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

There is disclosed herein an apparatus for converting control signals of an electrical or optical nature of any other type or 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 far 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 a 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. This causes the flexible wall to flex outward. This outward flex movement may then be used to either shut off a fluid flow path, or be sensed in some manner when using the device …