Method and structure for a pusher-mode piezoelectrically actuated liquid metal switch

• US 7,012,354 B2
• Filed: 04/14/2003
• Issued: 03/14/2006
• Est. Priority Date: 04/14/2003
• Status: Expired due to Fees

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Wong, Marvin Glenn
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US10/413,098
• Publication Number:
  US 20040201317A1
• Time in Patent Office: 1,065 Days
• Field of Search: 310/328, 310/348, 200/182, 200/214, 200/215, 200/219, 335/47, 335/49, 335/51, 335/58
• US Class Current: 310/328
• CPC Class Codes: H01H 2029/008 using micromechanics, e.g. micromechanical liquid contact switches or [LIMMS]
• CPC Class Codes: H01H 2057/006 Micromechanical piezoelectric relay
• CPC Class Codes: H01H 29/28 with level of surface of contact liquid displaced by fluid pressure
• CPC Class Codes: H01H 57/00 Electrostrictive relays; Piezoelectric relays

Abstract

A method and structure for an electrical switch. According to the structure of the present invention, a liquid-filled chamber is housed within a solid material. A plurality of switch contacts within the liquid-filled chamber are coupled to the solid material, while a plurality of piezoelectric elements are coupled to a plurality of membranes. The plurality of membranes are coupled to the liquid-filled chamber. The plurality of switch contacts are coupled to a plurality of liquid metal globules. According to the method, a piezoelectric element is actuated, causing a membrane element to be deflected. The deflection of the membrane element increases pressure of actuator liquid and the increase in pressure of the actuator liquid breaks a liquid metal connection between a first contact and a second contact of the electrical switch.

Claims

1. A structure for an electrical switch, comprising:

a chamber housed within a solid material, said chamber filled with an actuator liquid;

a plurality of switch contacts within the chamber, wherein the plurality of switch contacts are coupled to the solid material;

a plurality of liquid metal globules, coupled to the plurality of switch contacts and coupled to the chamber; and

a plurality of piezoelectric elements coupled to a plurality of membranes, said plurality of membranes coupled to the chamber, wherein the plurality of piezoelectric elements are within a reservoir, said reservoir containing actuating liquid.

2. The structure of claim 1, wherein the actuator liquid is inert and electrically non-conductive.

3. The structure of claim 1, wherein the actuating liquid is an inert, low viscosity, high boiling fluid.

4. The structure of claim 1, wherein the one or more liquid metal globules are composed of mercury.

5. The structure of claim 1, wherein the plurality of membranes are coupled to a corresponding plurality of orifices, wherein an orifice of the plurality of orifices is operable to increase a rate of flow of the actuating liquid.

6. The structure of claim 1, wherein the plurality of membranes have a corresponding plurality of widths, said corresponding plurality of widths being greater than an extent in a non-actuating direction of the plurality of piezoelectric elements.

7. The structure of claim 1, wherein the plurality of piezoelectric elements are further coupled to a corresponding plurality of contacts, said plurality of contacts operable to actuate the plurality of piezoelectric elements.

8. The structure of claim 7, wherein each contact of the plurality of contacts comprise a first terminal coupled to a first end of a piezoelectric element and a second terminal coupled to a second end of the piezoelectric element.

9. The structure of claim 8, wherein the first terminal and the second terminal are separated by a dielectric.

10. A structure for an electrical switch, comprising:

a piezoelectric substrate layer;

an actuator fluid reservoir layer coupled to the piezoelectric substrate layer, said actuator fluid reservoir layer further comprising one or more piezoelectrically actuated pusher elements;

a membrane layer coupled to the actuator fluid reservoir layer, said membrane layer comprising one or more membranes coupled to the one or more piezoelectrically actuated pusher elements;

a liquid metal channel layer coupled to the membrane layer;

a circuit substrate layer coupled to the liquid metal channel layer; and

an actuator liquid-filled chamber housed within the liquid metal channel layer, wherein the actuator liquid-filled chamber comprises one or more globules of liquid metal coupled to one or more switch contacts, said actuator liquid-filled chamber coupled to the one or more membranes.

11. The structure of claim 10, wherein the actuator fluid reservoir layer, piezoelectric substrate layer, membrane layer, circuit substrate layer and liquid metal channel layer are comprised of one or more of glass, ceramic, composite material and ceramic-coated material.

12. The structure of claim 10, wherein the actuator fluid reservoir layer further comprises a fill port, said fill port operable to be used for filling a reservoir of the actuator fluid reservoir layer with actuator fluid.

13. The structure of claim 10, wherein the circuit substrate layer further comprises a plurality of circuit traces and a plurality of pads operable to route one or more signals generated by actuation of one or more of the plurality of piezoelectric elements.

14. The structure of claim 10, wherein the actuator liquid is inert and electrically non-conductive.

15. The structure of claim 10, wherein the one or more liquid metal globules are composed of mercury.

16. The structure of claim 10, wherein the plurality of piezoelectric elements are further coupled to a corresponding plurality of contacts, said plurality of contacts operable to actuate the plurality of piezoelectric elements.

17. The structure of claim 16, wherein each contact of the plurality of contacts comprise a first terminal coupled to a first end of a piezoelectric element and a second terminal coupled to a second end of the piezoelectric element.

18. The structure of claim 17, wherein the first terminal and the second terminal are separated by a dielectric.

19. The structure of claim 10, wherein the plurality of membranes are coupled to a corresponding plurality of orifices, wherein an orifice of the plurality of orifices is operable to increase a rate of flow of the actuating liquid.

20. The structure of claim 19, wherein the plurality of orifices are located in the liquid metal channel layer.

21. A method for electrical switching of one or more electrical signals using a liquid metal switch, comprising:

actuating a piezoelectric element;

deflecting a membrane element by the actuation of the piezoelectric element;

increasing a pressure of actuator liquid by the deflection of the membrane element;

the increase in pressure of the actuator liquid breaking a liquid metal connection between a first contact and a second contact of the liquid metal switch, wherein the liquid metal connection is maintained by a surface tension between a liquid metal and the first contact and the second contact; and

after breaking the liquid metal connection establishing a second liquid metal connection between the second contact and a third contact, further comprising;

breaking the second liquid metal connection by application of a second electric potential with a polarity opposite the first electric potential, said second electric potential actuating the piezoelectric element so that a negative pressure is exerted on the membrane element thereby pulling the liquid metal to re-establish the liquid metal connection between the first contact and the second contact and break the second liquid metal connection between the third contact and the second contact.

22. The method of claim 21, wherein the piezoelectric element is actuated by an application of an electric potential applied to a first side and a second opposite side of the piezoelectric element.

23. The method of claim 21, wherein prior to an operation of the electrical switch, actuator fluid is added to the liquid metal switch using a fill port.

24. The method of claim 21, wherein an orifice is used to increase a flow rate of actuator liquid caused by the increase in pressure, said increased flow rate operable to more rapidly break the liquid metal connection.

25. The method of claim 21, further comprising breaking the second liquid metal connection by the use of a second piezoelectric element, a second membrane element, a second electric potential, whereby the second electric potential actuates the second piezoelectric element causing the second membrane element to deflect and increase the pressure of the actuator fluid, said actuator fluid then being operable to flow and break the second liquid metal connection.