Abstract: Due to restrictive tolerancing, structural imperfections that reduce performance of fabricated micro gyroscopes are typical. While feedback control is normally used to compensate for these imperfections, there are limitations to how large of errors for which this strategy can compensate without interfering with the performance of the sensor. A multi stage control architecture comprising in situ self-diagnostic capabilities, electronic “trimming” of errors, and feedback control allows for the compensation of all magnitudes of errors without interfering with the performance of the device. The self-diagnostic capabilities include an algorithm for determining structural imperfections based on the dynamic response of the system. The feedforward portion of the control is used to “trim” large imperfections, while the feedback portion compensates for the remaining non-idealities and small perturbations.

Abstract: A micromachined design and method with inherent disturbance-rejection capabilities is based on increasing the degrees-of-freedom (DOF) of the oscillatory system by the use of two independently oscillating proof masses. Utilizing dynamical amplification in the 4-degrees-of-freedom system, inherent disturbance rejection is achieved, providing reduced sensitivity to structural and thermal parameter fluctuations and damping changes over the operating time of the device. In the proposed system, the first mass is forced to oscillate in the drive direction, and the response of the second mass in the orthogonal direction is sensed. The response has two resonant peaks and a flat region between peaks. Operation is in the flat region, where the gain is insensitive to frequency fluctuations. An over 15 times increase in the bandwidth of the system is achieved due to the use of the proposed architecture. In addition, the gain in the operation region has low sensitivity to damping changes.

Abstract: A micromachined angle measuring gyroscope using a dual mass architecture measures angular positions rather than angular rates. The invention decouples the effects of drive and sense through the use of a dual mass architecture, and is comprised of a single lumped drive mass, which is structurally coupled to a second lumped slave mass, where the drive mass is electrostatically driven at the first resonant frequency the system using parallel plate electrodes. The slave mass is driven to higher amplitudes than the drive mass. In the presence of rotation, the line of oscillation in both masses precesses, which is easily detectable in the slave mass due to the amplified motion, and is exactly equal to the angle of rotation. The two illustrated embodiments are z-axis realizations of this principle, where the first device uses an inner drive/outer sense architecture and the second uses an outer drive/inner sense architecture.

Abstract: A hybrid process combines a thin-film surface micromachining process such as by sputtering, evaporation or chemical vapor deposition with a thick-film surface micromachining and release process such as dry-film lamination. Such combination results in thin film micro-structures with all the benefits of surface micromachining without the typical problems of stiction and limited range of motion.

Abstract: A micro-machined angle measurement gyroscope. In one implementation, the gyroscope includes a substrate; a proof mass coupled to the substrate by an isotropic suspension such that the proof mass can move in any direction in the plane of the substrate; a plurality of drive electrodes configured to cause the proof mass to oscillate in the plane of the substrate; and a plurality of sense electrodes configured to sense the motion of the proof mass in the plane of the substrate. In another implementation, the gyroscope includes a substrate; a proof mass suspended above the substrate by an isotropic suspension such that the proof mass can move in any direction in an oscillation plane normal to the substrate; a plurality of drive electrodes configured to cause the proof mass to oscillate in the oscillation plane; and a plurality of sense electrodes configured to sense the motion of the proof mass in the oscillation plane.

Abstract: A sequence of MEMS processing steps are used to construct a 2D optical switch on a single substrate. In a typical optical switch configuration, an array of hinged micromirrors are supported by an array of posts at a 45° angle to the input and output optical paths and positioned parallel to the substrate either above, below or, perhaps, in the optical paths. The application of a voltage between the mirror and its control electrodes switches the mirror to a vertical position where it intercepts and deflects light travelling down the optical paths. The posts are suitably oriented at a 90° angle with respect to the mirror hinges so that they do not interfere with the optical paths and, may be configured to function as baffles to reduce crosstalk between adjacent optical paths.