Actuator plate partitioning and control devices and methods
Devices and methods of operating partitioned actuator plates to obtain a desirable shape of a movable component of a micro-electro-mechanical system (MEMS) device. The subject matter described herein can in some embodiments include a micro-electro-mechanical system (MEMS) device including a plurality of actuation electrodes attached to a first surface, where each of the one or more actuation electrode being independently controllable, and a movable component spaced apart from the first surface and movable with respect to the first surface. Where the movable component further includes one or more movable actuation electrodes spaced apart from the plurality of fixed actuation electrodes.
1. A micro-electro-mechanical system (MEMS) device comprising:
a plurality of fixed actuation electrodes attached to a first surface, wherein each of the plurality of actuation electrodes is independently controllable;
a fixed capacitor plate fixed to the first surface; and
a movable component spaced apart from the first surface and movable with respect to the first surface, the movable component comprising one or more movable actuation electrodes spaced apart from the plurality of fixed actuation electrodes and a movable capacitor electrode spaced from the fixed capacitor plate;
a controller in communication with the plurality of actuation electrodes and configured to selectively actuate a first number of the plurality of actuation electrodes during a pull-in phase to deflect the movable component towards the first surface and to de-actuate one or more of the first number of the plurality of actuation electrodes while maintaining the movable component in a deflected position during a hold down phase, wherein a second number of the plurality of actuation electrodes that is less than the first number remains actuated during the hold down phase to adjust a shape of the movable component such that the movable capacitor electrode is optimally flattened to maximize a capacitance between the movable capacitor electrode and the fixed capacitor plate in the hold down phase.
2. The MEMS device of claim 1 , wherein the plurality of fixed actuation electrodes are selectively controllable to deflect the movable component relative to the first surface to any of a plurality of positions corresponding to a plurality of capacitance states of the fixed capacitor plate and the movable capacitive electrode.
3. The MEMS device of claim 1 further comprising at least one standoff bump attached to at least one of the plurality of actuation electrodes, wherein the at least one standoff bump is configured to prevent contact between the actuation electrodes and the movable component.
4. The MEMS device of claim 1 further comprising a plurality of independently-controllable voltage drivers each connected to one of the plurality of actuation electrodes.
5. The MEMS device of claim 1 further comprising a second surface spaced apart from the movable component;
wherein the movable component is positioned between the first and second surface and is movable toward the first or second surface.
6. The MEMS device of claim 5 , comprising one or more standoff pivots attached to one of the first or second surfaces or the movable component, wherein actuation of one or more of the plurality of fixed actuation electrodes positioned on one side of one of the one or more standoff pivot can cause a portion of the movable component on an opposing side of the standoff pivot to deflect away from the first or second surface.
7. The MEMS device of claim 1 , wherein the movable component is connected to the first surface by at least one fixed anchor.
8. A method for adjusting a shape of a movable component of a Micro-electro-mechanical system (MEMS) device comprising:
in a pull-in phase, deflecting a movable component towards a first surface by selectively actuating a first number of a plurality of fixed actuation electrodes using one or more independently controllable voltage driver, wherein the fixed actuation electrodes are independently controllable and attached to the first surface;
in a hold-down phase, selectively de-actuating one or more of the first number of the plurality of fixed actuation electrodes while maintaining the movable component in a deflected position, wherein a second number of the plurality of fixed actuation electrodes that is less than the first number remain actuated to adjust a shape of the movable component;
wherein a movable capacitor electrode is attached to the movable component and a fixed capacitor plate is fixed to the first surface; and
wherein adjusting the shape of the movable component comprises deflecting the movable component into a shape such that the movable capacitor electrode is optimally flattened to maximize a capacitance between the movable capacitor electrode and the fixed capacitor plate in the hold down phase.
9. The method of claim 8 , wherein selectively de-actuating at least one of the first number of the plurality of fixed actuation electrodes comprises de-actuating at least one of the plurality of actuation electrodes that is positioned adjacent to the fixed capacitor plate, the at least one of the plurality of actuation electrodes acting as a shield ring for the fixed capacitor plate.
10. The method of claim 8 , wherein adjusting the shape of the movable component comprises changing a spacing between the movable capacitor plate and the fixed capacitor plate.
11. The method of claim 8 , wherein adjusting the shape of the movable component comprises actuating at least one actuation electrode on one side of a standoff pivot to cause a portion of the movable component on an opposing side of the standoff pivot to deflect away from the first surface.
12. The method of claim 11 , actuating at least one actuation electrode on one side of a standoff pivot comprises increasing a self-actuation release voltage between the movable capacitor plate and the fixed capacitor plate for high power hot switching.