An acceleration sensing structure includes a frame, a proof mass, a gimbal and at least two outer flexible arms. The proof mass is suspended from the frame and has a first thickness. The proof mass is surrounded by and connected to the gimbal. The gimbal has a second thickness. The at least two outer flexible arms are connected between the gimbal and the frame, and the at least two outer flexible arms are arranged symmetrically. The second thickness is larger than or equal to one-half of the first thickness and is smaller than or equal to the first thickness, and when the proof mass moves, the at least two outer flexible arms are deformed.

A resonant mechanical structure, such as one for use in a torsional oscillator MEMS accelerometer that includes a mounting substrate and a reference mass configured to move within a reference mass plane, the resonant mechanical structure being connected to the mounting structure and the reference mass, and the resonant mechanical structure including a body, a center of mass, and an aperture, wherein the aperture is surrounded and defined by the body, and wherein the body includes a first mass portion and a second mass portion that are configured to oscillate about an oscillation axis located within the reference mass plane, wherein the center of mass is located on the oscillation axis, and wherein a movement of the reference mass within the reference mass plane varies a moment of inertia of the body while the center of mass of the body remains located on the oscillation axis.

An acceleration sensing structure includes a frame, a proof mass, a gimbal and at least two outer flexible arms. The proof mass is suspended from the frame and has a first thickness. The proof mass is surrounded by and connected to the gimbal. The gimbal has a second thickness. The at least two outer flexible arms are connected between the gimbal and the frame, and the at least two outer flexible arms are arranged symmetrically. The second thickness is larger than or equal to one-half of the first thickness and is smaller than or equal to the first thickness, and when the proof mass moves, the at least two outer flexible arms are deformed.

A contamination detector device may compute a cross-sensitivity of a pressure sensor based on an amount of pressure change sensed by the pressure sensor and an amount of acceleration change sensed by an acceleration sensor. The cross-sensitivity of the pressure sensor indicates a measure of sensitivity of the pressure sensor to acceleration. The contamination detector device may determine, based on the cross-sensitivity of the pressure sensor, whether the pressure sensor is contaminated. The contamination detector device may selectively perform a contamination action based on whether the pressure sensor is contaminated.

A resonant mechanical structure, such as one for use in a torsional oscillator MEMS accelerometer that includes a mounting substrate and a reference mass configured to move within a reference mass plane, the resonant mechanical structure being connected to the mounting structure and the reference mass, and the resonant mechanical structure including a body, a center of mass, and an aperture, wherein the aperture is surrounded and defined by the body, and wherein the body includes a first mass portion and a second mass portion that are configured to oscillate about an oscillation axis located within the reference mass plane, wherein the center of mass is located on the oscillation axis, and wherein a movement of the reference mass within the reference mass plane varies a moment of inertia of the body while the center of mass of the body remains located on the oscillation axis.

A contamination detector device may compute a cross-sensitivity of a pressure sensor based on an amount of pressure change sensed by the pressure sensor and an amount of acceleration change sensed by an acceleration sensor. The cross-sensitivity of the pressure sensor indicates a measure of sensitivity of the pressure sensor to acceleration. The contamination detector device may determine, based on the cross-sensitivity of the pressure sensor, whether the pressure sensor is contaminated. The contamination detector device may selectively perform a contamination action based on whether the pressure sensor is contaminated.