Gas-damped micromechanical structure
AssigneeLucent Technologies Inc.
InventorDennis S. Greywall
Life of this patent
Estimating the term…
Abstract
An improved squeeze-type micromechanical structure for high speed operation, i.e., greater than 1 MHz, is disclosed. The structure has a movable member possessing damping holes. The porosity, 1/(.omega..sub.o .tau.), of the movable member is at least about 1.4. The structure is hermetically sealed and is maintained above atmospheric pressure and at a minimum reduced pressure or gas frequency, .omega..sub.g /.omega..sub.o, of about 1.3. To operate with less than 10 percent "ringing," .omega..sub.g /.omega..sub.o >1.3 and 0.25+0.7(.omega..sub.g /.omega..sub.o).sup.2 -0.8(.omega..sub.g /.omega..sub.o -1.25).ltoreq.1/(.omega..sub.o .tau.).ltoreq.0.25+0.7(.omega..sub.g /.omega..sub.o).sup.2 +(.omega..sub.g /.omega..sub.o -1.25).
Claims18
A high-speed gas-damped micromechanical structure comprising:
- a movable member;
- a gas-tight seal enclosing the movable member;
- and
- a gas within the gas-tight seal, wherein,
- ambient pressure within the gas-tight seal is greater than about one atmosphere and no more than about 48 atmospheres.
A high-speed gas-damped micromechanical structure comprising:
- a movable member having a plurality of holes for allowing the passage of gas from a first side of the member to a second side of the member during oscillatory motion of the member;
- wherein, ambient pressure of the member is less than about 48 atmospheres, and further wherein 1/(.omega..sub.o .tau.) is at least about 1.4 and .omega..sub.g /.omega..sub.o is at least about 1.3, where,
- 1/(.omega..sub.o .tau.) is a measure of porosity of the movable member;
- .omega..sub.g /.omega..sub.o is reduced gas frequency;
- and
- .omega..sub.o is resonant frequency of the member in a vacuum.
A micromechanical optical modulator comprising:
- a movable layer suspended above a non-moving layer, the two layers forming a modulator cavity therebetween;
- a gas-tight seal formed over the movable layer;
- and
- a gas, wherein,
- when the movable layer moves toward the non-moving layer in response to a signal, a portion of the gas flows out of the modulator cavity providing damping to the movable layer, and further wherein the ambient pressure due to the gas is greater than about one atmosphere and no more than about 48 atmospheres.
A high-speed gas-damped micromechanical structure comprising:
- a movable member;
- a gas-tight seal enclosing the movable member;
- and
- a gas within the gas-tight seal, wherein,
- 0.25+0.7(.omega..sub.g /.omega..sub.o).sup.2 -0.8(.omega..sub.g /.omega..sub.o -1.25).ltoreq.1/(.omega..sub.o .tau.).ltoreq.0.25+0.7(.omega..sub.g /.omega..sub.o).sup.2 +(.omega..sub.g /.omega..sub.o -1.25).
- 1/(.omega..sub.o .tau.) is a measure of porosity of the movable member;
- .omega..sub.g /.omega..sub.o is reduced gas frequency;
- and
- .omega..sub.o is resonant frequency of the member in a vacuum.
Dependencies are inferred from the claim text.