MEMS valve

• US 6,612,535 B1
• Filed: 01/23/1998
• Issued: 09/02/2003
• Est. Priority Date: 01/24/1997
• Status: Expired due to Term

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Tai, Yu-Chong, Yang, Xing, Grosjean, Charles
• Primary Examiner(s): Walton, George L.
• Application Number:
  US09/012,309
• Time in Patent Office: 2,048 Days
• Field of Search: 251/11, 251/129.01, 251/129.06, 605/27, 605/28, 605/29, 605/30
• US Class Current: 251/11
• CPC Class Codes: B81B 2201/054 Microvalves
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: F15C 5/00 Manufacture of fluid circuit elements; Manufacture of assemblages of such elements integrated circuits
• CPC Class Codes: F16K 2099/0074 using photolithography, e.g. etching
• CPC Class Codes: F16K 2099/008 Multi-layer fabrications
• CPC Class Codes: F16K 99/0001 Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0015 Diaphragm or membrane valves
• CPC Class Codes: F16K 99/0044 using thermo-electric means
• CPC Class Codes: F16K 99/0061 actuated by an expanding gas or liquid volume

Abstract

A valve where the valve membrane is made from silicone rubber. Preferably the valve is a microelectromechanical systems (MEMS) thermopneumatic valve. Because of the advantageous physical properties of silicone rubber, the valve provides desirable performance with reasonable power consumption.

Claims

1. A microelectronic valve comprising:

a first substrate defining an inlet part, an outlet part and a channel cavity extending between said inlet part and said outlet part with a valve seat in said channel cavity at a location allowing sealing between said inlet and outlet;

a valve membrane formed of silicone rubber coupled within said channel cavity; and

a valve actuator, coupled to said first substrate, including a heater and a fluid, which fluid is heated when actuated to expand to expand and press against said valve seat.

2. A valve as in claim 1, wherein said elastomeric valve element expands to block an entirety of both said inlet part and said outlet part.

3. A microelectronic valve membrane chip comprising:

a wafer;

a first cavity defined in the wafer;

a second cavity defined in the wafer;

an aperture between the first cavity and the second cavity;

a valve membrane formed of silicone rubber, and at least partially occupying the aperture such that a gap remains between a plane formed by a front surface of the valve membrane and said first and second cavities;

a thermopneumatic actuator coupled to the back side of the wafer, said actuator configured to produce heat on energization provide actuation for said valve membrane;

an actuator fluid disposed in contact with said valve membrane, said actuator fluid operating to provide an appropriate thermal condition desired for actuator operation,

said valve membrane being expanded when said fluid is at said appropriate thermal condition, to completely occupy the aperture and to close said gap; and

a third cavity, defined in said wafer, also holding said actuator fluid.

4. The MEMS valve membrane chip of claim 3 where the valve membrane is made from silicone rubber.

5. The MEMS valve membrane chip of claim 3 where the valve membrane is a composite membrane comprising a sealing film between the second cavity and the silicone rubber.

6. A valve, comprising:

a first substrate portion, including to a top substrate surface and a bottom substrate surface, and a first and second channels extending between said top substrate surface and said bottom substrate surface;

a second substrate portion, including an elastomeric valve element, which, when in an un stretched state, occupies a portion below the bottom substrate surface, leaving a channel between said first and second channels along said bottom substrate surface;

a third substrate portion, including an expandable fluid, and an actuator which is selectively actuatable to expand said expandable fluid, said expandable fluid occupying a portion adjacent said elastomeric valve element and expanding said valve element to block said portion between said first and second channels, by pressing against said bottom substrate surface.

7. A valve as in claim 6, wherein said the third substrate portion includes a first cavity, and at least one downwardly expanding channel, forming a reservoir for said expandable fluid.

8. A valve as in claim 6, wherein said elastomeric valve element expands to block an entirety of both said first and second channels against said bottom substrate surface.