A MEMS device includes a movable mass having a central region overlying a sense electrode and an opening in which a suspension structure and spring system are located. The suspension structure includes an anchor coupled to a substrate and rigid links extending from opposing sides of the anchor. The spring system includes a first and second spring heads coupled to each of the rigid links. A first drive spring is coupled to the first spring head and to the movable mass, and a second drive spring is coupled to the second spring head and to the movable mass. The movable mass is resiliently suspended above the surface of the substrate via the suspension structure and the spring system. The spring system enables drive motion of the movable mass in the drive direction and sense motion of the movable mass in a sense direction perpendicular to the surface of the substrate.

A MEMS device includes a movable mass having a central region overlying a sense electrode and an opening in which a suspension structure and spring system are located. The suspension structure includes an anchor coupled to a substrate and rigid links extending from opposing sides of the anchor. The spring system includes a first and second spring heads coupled to each of the rigid links. A first drive spring is coupled to the first spring head and to the movable mass, and a second drive spring is coupled to the second spring head and to the movable mass. The movable mass is resiliently suspended above the surface of the substrate via the suspension structure and the spring system. The spring system enables drive motion of the movable mass in the drive direction and sense motion of the movable mass in a sense direction perpendicular to the surface of the substrate.

A bulk acoustic wave resonator apparatus includes a resonator member, at least one anchor structure coupling the resonator member to a substrate, and a comb-drive element connected to the resonator member. The comb-drive element includes first comb fingers protruding from the resonator member, and second comb fingers of a different material than the first comb fingers interdigitated with the first comb fingers to define sub-micron capacitive gaps therebetween. Respective sidewalls of the first comb fingers are oppositely-tapered relative to respective sidewalls of the second comb fingers along respective lengths thereof, such that operation of the comb-drive element varies the sub-micron capacitive gaps at the respective sidewalls thereof. Respective tuning electrodes, which are slanted at respective angles parallel to an angle of respective sidewalls of the resonator member, may also be provided for quadrature tuning between different resonance modes of the resonator member. Related devices and fabrication methods are also discussed.

A bulk acoustic wave resonator apparatus includes a resonator member, at least one anchor structure coupling the resonator member to a substrate, and a comb-drive element connected to the resonator member. The comb-drive element includes first comb fingers protruding from the resonator member, and second comb fingers of a different material than the first comb fingers interdigitated with the first comb fingers to define sub-micron capacitive gaps therebetween. Respective sidewalls of the first comb fingers are oppositely-tapered relative to respective sidewalls of the second comb fingers along respective lengths thereof, such that operation of the comb-drive element varies the sub-micron capacitive gaps at the respective sidewalls thereof. Respective tuning electrodes, which are slanted at respective angles parallel to an angle of respective sidewalls of the resonator member, may also be provided for quadrature tuning between different resonance modes of the resonator member. Related devices and fabrication methods are also discussed.

Described herein are methods and systems for configuring a motion sensor assembly to compensate for a temperature gradient. First and second sensors of the same type are arranged as opposing pairs with respect to a first axis that may be defined by a temperature gradient caused by at least one thermal element. Combining the output measurements of the first sensor and the second sensor allows effects of the temperature gradient on sensor measurements of the first sensor and the second sensor to be compensated.

Described herein are methods and systems for configuring a motion sensor assembly to compensate for a temperature gradient. First and second sensors of the same type are arranged as opposing pairs with respect to a first axis that may be defined by a temperature gradient caused by at least one thermal element. Combining the output measurements of the first sensor and the second sensor allows effects of the temperature gradient on sensor measurements of the first sensor and the second sensor to be compensated.

An inertial navigation system includes a first inertial measurement unit with at least a first sensor and a second inertial measurement unit with at least a second sensor corresponding in type to the first sensor. The first inertial measurement unit is rotatably mounted relative to the second inertial measurement unit, The inertial navigation system further include a controller arranged to: acquire a first set of measurements simultaneously from both the first inertial measurement unit and the second inertial measurement unit; rotate the first inertial measurement unit relative to the second inertial measurement unit; acquire a second set of measurements simultaneously from both the first inertial measurement unit and the second inertial measurement unit; and calculate from the first set of measurements and the second set of measurements at least one error characteristic of the first sensor and/or the second sensor.

An inertial navigation system includes a first inertial measurement unit with at least a first sensor and a second inertial measurement unit with at least a second sensor corresponding in type to the first sensor. The first inertial measurement unit is rotatably mounted relative to the second inertial measurement unit, The inertial navigation system further include a controller arranged to: acquire a first set of measurements simultaneously from both the first inertial measurement unit and the second inertial measurement unit; rotate the first inertial measurement unit relative to the second inertial measurement unit; acquire a second set of measurements simultaneously from both the first inertial measurement unit and the second inertial measurement unit; and calculate from the first set of measurements and the second set of measurements at least one error characteristic of the first sensor and/or the second sensor.

A dual-shell architecture and methods of fabrication of fused quartz resonators is disclosed. The architecture may include two encapsulated and concentric cavities using plasma-activated wafer bonding followed by the high-temperature glassblowing. The dual-shell architecture can provide a protective shield as well as a “fixed-fixed” anchor for the sensing element of the resonators. Structures can be instrumented to operate as a resonator, a gyroscope, or other vibratory sensor and for precision operation in a harsh environment. Methods for fabricating a dual-shell resonator structure can include pre-etching cavities on a cap wafer, pre-etching cavities on a device wafer, bonding the device wafer to a substrate wafer to form a substrate pair and aligning and bonding the cap wafer to the substrate pair to form a wafer stack with aligned cavities including a cap cavity and a device cavity. The wafer stack may be glassblown to form a dual-shell structure.

A dual-shell architecture and methods of fabrication of fused quartz resonators is disclosed. The architecture may include two encapsulated and concentric cavities using plasma-activated wafer bonding followed by the high-temperature glassblowing. The dual-shell architecture can provide a protective shield as well as a “fixed-fixed” anchor for the sensing element of the resonators. Structures can be instrumented to operate as a resonator, a gyroscope, or other vibratory sensor and for precision operation in a harsh environment. Methods for fabricating a dual-shell resonator structure can include pre-etching cavities on a cap wafer, pre-etching cavities on a device wafer, bonding the device wafer to a substrate wafer to form a substrate pair and aligning and bonding the cap wafer to the substrate pair to form a wafer stack with aligned cavities including a cap cavity and a device cavity. The wafer stack may be glassblown to form a dual-shell structure.