Method and apparatus for maintaining a liquid metal switch in a ready-to-switch condition

• US 20040201330A1
• Filed: 04/14/2003
• Published: 10/14/2004
• Est. Priority Date: 04/14/2003
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Fong, Arthur, Wong, Marvin Glenn
• Granted Patent: US 6,946,776 B2
• Time in Patent Office: Days
• US Class Current: 310/365
• CPC Class Codes: G02B 26/004 based on a displacement or a deformation of a fluid
• 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 50/005 using micromechanics
• CPC Class Codes: H01H 55/00 Magnetostrictive relays
• CPC Class Codes: H01H 57/00 Electrostrictive relays; Piezoelectric relays

Abstract

A method and apparatus for maintaining a liquid metal switch in a state of readiness for switching. The liquid metal switch has a liquid metal volume contained in a cavity of a switch body. A signal path though the cavity is made or broken by energizing an actuator to move the liquid metal volume within the cavity in response to a switching signal. To maintain readiness, a signal generator supplies a vibratory signal to the actuator. The resulting vibrations in the liquid metal volume allow the liquid metal volume to be subsequently moved with reduced power.

Claims

1. A method for operating a liquid metal switch, the method comprising:

vibrating a liquid metal volume within the switch in response to vibratory signal supplied to an actuator acting on the liquid metal volume, whereby the switch is maintained in a state of readiness; and

moving the liquid metal volume in response to a switching signal supplied to the actuator so as to make or break a signal path through the switch.

2. A method in accordance with claim 1, further comprising combining the vibratory signal and the switching signal before supplying them to the actuator.

3. A method in accordance with claim 1, wherein moving the liquid metal volume comprises creating a pressure change within a cavity containing the liquid metal volume so as to create a pressure difference across the liquid metal volume.

4. A method in accordance with claim 2, wherein the pressure change is created by heating a gas in the cavity.

5. A method in accordance with claim 2, wherein the pressure change is created by heating a liquid in the cavity so as to cause the liquid to change state.

6. A method in accordance with claim 2, wherein the pressure change is created by altering the volume of the cavity.

7. A method in accordance with claim 6, wherein the cavity is bounded at least in part by a diaphragm and volume of the cavity is changed by deforming the diaphragm.

8. A method in accordance with claim 7, wherein the actuator is a piezoelectric element acting on the diaphragm.

9. A method in accordance with claim 1, wherein moving the liquid metal volume comprises generating an electromagnetic field in a cavity containing the liquid metal volume.

10. A method in accordance with claim 1, wherein electromagnetic field is generated using an electrical coil surrounding the cavity.

11. A method in accordance with claim 1, wherein the vibratory signal is supplied intermittently.

12. A method in accordance with claim 1, wherein the vibratory signal is supplied continuously.

13. A method in accordance with claim 1, wherein the signal path is an electrical path completed by moving the liquid metal volume into the electrical path.

14. A method in accordance with claim 1, wherein the signal path is an optical path broken by moving the liquid metal volume into the optical path.

15. A liquid metal switch comprising:

a switch body having a cavity therein;

a liquid metal volume contained in the cavity;

an actuator operable to make or break a signal path though the cavity by moving the liquid metal volume within the cavity in response to a switching signal; and

a signal generator electrically coupled to the actuator and operable to supply a vibratory signal to the actuator, thereby maintaining the switch in a state of readiness.

16. A liquid metal switch in accordance with claim 15, wherein the actuator is operable to produce a pressure change within the cavity so as to create a pressure difference across the liquid metal volume.

17. A liquid metal switch in accordance with claim 16, wherein the actuator is a heater.

18. A liquid metal switch in accordance with claim 16, wherein the actuator is a piezoelectric element.

19. A liquid metal switch in accordance with claim 15, wherein the cavity is bounded at least in part by a diaphragm and volume of the cavity is changed by deforming the diaphragm.

20. A liquid metal switch in accordance with claim 19, wherein the actuator is a piezoelectric element acting on the diaphragm.

21. A liquid metal switch in accordance with claim 15, wherein the actuator is an electric coil operable to generate an electromagnetic field in the cavity.