US 2016/0097789 A1 · PERFORMANCE IMPROVEMENT OF MEMS DEVICES

Abstract

A microelectromechanical-systems (MEMS) device includes a driven mass and has a natural stiffness or damping. An actuator applies force to the mass, movement of which is measured by a sensing capacitor. A control circuit operates the actuator per displacement or velocity of the driven mass, so that a characteristic stiffness or damping of the mechanical subsystem is different from the respective natural value. A method of transforming a MEMS device design includes determining an aim performance value of the design and a baseline performance uncertainty of the design, selecting candidate sets of parameter values, determining a candidate, first, and second performance value for each, scoring the candidates, and repeating until one of the candidates satisfies a termination criterion, so the transformed design using that candidate set has the aim performance value and the respective first and second performance values closer to each other than the baseline performance uncertainty.

Claims16

Dependent claims

A microelectromechanical-systems (MEMS) device, comprising:

a) a mechanical subsystem including a driven mass, the subsystem having a natural stiffness or a natural damping, wherein the mass is at least partly movable or at least partly deformable;
b) an actuator responsive to a time-varying control signal to apply force to the driven mass;
c) a sensing capacitor including a first plate attached to and movable with the driven mass and a second plate substantially fixed in position, wherein a capacitance of the sensing capacitor varies as the driven mass moves;
d) a measurement circuit responsive to the capacitance of the sensing capacitor to provide first and second signals corresponding respectively to a displacement and to a velocity of the driven mass;
and
e) a control circuit configured to provide the time-varying control signal to the actuator in response to the first signal or the second signal and in response to a selected parameter, so that a characteristic stiffness or a characteristic damping of the mechanical subsystem is different from the natural stiffness or the natural damping, respectively, while the time-varying control signal is applied to the actuator.

3 more elements

A method of transforming a microelectromechanical-systems (MEMS) device design with respect to a set of one or more parameters having selected initial values, the method comprising automatically performing the following steps using a processor:

using selected uncertainty values of the parameters, automatically determining first and second parameter offset sets of the design;
using the selected initial values of the parameters and the first and second parameter offset sets, determining an aim performance value of the design and a baseline performance uncertainty of the design;
a setup step of selecting a plurality of candidate sets of parameter values using the initial values;
determining a respective candidate performance value of the design for each of the candidate sets;
applying the first and second parameter offset sets to each of the candidate sets and determining respective first and second performance values of the design;
a scoring step of determining a respective score of each of the candidate sets using the aim performance value, the respective candidate performance value, and the respective first and second performance values;
a testing step of, if none of the respective scores satisfies a selected termination criterion, repeating the setup through testing steps using a selected one of the candidate sets in place of the initial values, so that one of the candidate sets is selected as a transformation of the design, and the transformed design has the respective candidate performance value corresponding to the aim performance value and the respective first and second performance values closer to each other than the baseline performance uncertainty.

4 more elements

Dependencies are inferred from the claim text.

Performance improvement of mems devices

Life of this patent

Performance improvement of mems devices

Life of this patent

Abstract

Claims16