Three-axis monolithic microelectromechanical system (MEMS) accelerometers and methods for fabricating integrated capacitive and piezo accelerometers are provided. In an embodiment, a three-axis MEMS accelerometer includes a first sensing structure for sensing acceleration in a first direction. Further, the three-axis MEMS accelerometer includes a second sensing structure for sensing acceleration in a second direction perpendicular to the first direction. Also, the three-axis MEMS accelerometer includes a third sensing structure for sensing acceleration in a third direction perpendicular to the first direction and perpendicular to the second direction. At least one sensing structure is a capacitive structure and at least one sensing structure is a piezo structure.

A force detecting device includes a first base section, a second base section, and a charge output element arranged between the first base section and the second base section. The charge output element includes a first board formed by a Y-cut quartz plate and a second board formed by a Y-cut quartz plate. The boards are laminated in a direction orthogonal to the normal an attachment surface of the second base section. The force detecting device detects an external force on the basis of a first output corresponding to a shearing force in a first detection direction orthogonal to the laminating direction of the first board and a second output corresponding to a shearing force in a second detection direction orthogonal to the laminating direction of the second board and crossing the first detection direction.

A force detecting device includes a first base section, a second base section, and a charge output element arranged between the first base section and the second base section. The charge output element includes a first board formed by a Y-cut quartz plate and a second board formed by a Y-cut quartz plate. The boards are laminated in a direction orthogonal to the normal an attachment surface of the second base section. The force detecting device detects an external force on the basis of a first output corresponding to a shearing force in a first detection direction orthogonal to the laminating direction of the first board and a second output corresponding to a shearing force in a second detection direction orthogonal to the laminating direction of the second board and crossing the first detection direction.

Apparatus and associated methods relate to maximizing a signal to noise ratio of an accelerometer by inhibiting signals arising from movements of a proofmass in directions perpendicular to a direction of intended sensitivity. The direction of intended sensitivity of the accelerometer is along an axis of the proofmass. The accelerometer is rendered substantially insensitive to lateral accelerations of the proofmass by making the accelerometer axially symmetric. Two axially-asymmetric acceleration sensing devices are axially engaged in such a manner as to render the coupled sensing devices substantially axially-symmetric. In some embodiments, each acceleration sensor has an axially-thin membrane portion extending from a proofmass portion. The two acceleration sensors can be engaged in an antiparallel fashion at projecting ends of the proofmass portions. An engagement surface will be located about halfway between the axially-thin membrane portions of the two acceleration sensors, thereby causing mechanical symmetry about the engagement surface.

An athletic parameter measurement device worn by an athlete during an athletic activity session includes a housing which attaches to the athlete, a display, a processor associated with the display, and an athletic parameter measurement sensor. During the athletic activity, the device detects, using the sensor, a vertical jump height of the athlete, and displays, during the performance of the athletic activity session, a representation of the vertical jump height on the display.

An athletic parameter measurement device worn by an athlete during an athletic activity session includes a housing which attaches to the athlete, a display, a processor associated with the display, and an athletic parameter measurement sensor. During the athletic activity, the device detects, using the sensor, a vertical jump height of the athlete, and displays, during the performance of the athletic activity session, a representation of the vertical jump height on the display.

Disclosed is an integrated acceleration, speed and vibration sensor. The sensor includes a housing, a base, a sensing and signal processing circuit, a current loop circuit, an anti-surge PTC and an aviation plug. The housing is mounted on the base. The sensing and signal processing circuit and the current loop circuit are used to fabricate a PCB circuit board, and then the PCB circuit board is mounted in the housing. A power supply and signal line is connected to the aviation plug. An M6 threaded hole is formed in a bottom of the housing of the sensor and is used to connect with an object to be detected. A power supply is negatively connected to one end of a varistor and the other end of the varistor is connected to the housing as the anti-surge PTC to play a protective role. The M6 threaded hole formed in the bottom of the housing of the sensor is used to connect with the object to be detected and improve the stability. At the same time, after the PCB circuit board is mounted, adhesive filling is performed to improve the vibration resistance.

A multi-axis, single mass acceleration sensor includes a three-dimensional frame, a test mass, a plurality of transducers, and a plurality of struts. The test mass may have three principal axes disposed within and spaced apart from the frame. The transducers are mechanically coupled to the frame. The struts are configured to couple to the central mass at each of the three principal axes, respectively, and to couple with respective sets of the transducers, thereby suspending the test mass within the frame. The sensor is thus responsive to translational motion in multiple independent directions and to rotational motion about multiple independent axes.

A combined MicroElectroMechanical structure (MEMS) includes a first piezoelectric membrane having one or more first electrodes, the first piezoelectric membrane being affixed between a first holder and a second holder; and a second piezoelectric membrane having an inertial mass and one or more second electrodes, the second piezoelectric membrane being affixed between the second holder and a third holder.

A combined MicroElectroMechanical structure (MEMS) includes a first piezoelectric membrane having one or more first electrodes, the first piezoelectric membrane being affixed between a first holder and a second holder; and a second piezoelectric membrane having an inertial mass and one or more second electrodes, the second piezoelectric membrane being affixed between the second holder and a third holder.