Micromachined sensing elements

Micromachined sensing elements are employed in:

• accelerometers for crash-detection in airbag-systems (front- or side-impact). The sensing principle is based on a capacitive detection of the displacement of the free movable comb-structure attached to the inertial mass in the center of the device with respect to the fixed comb-electrodes. Data evaluation is performed in a separate readout ASIC.
• low-g and inclination sensors for vehicle dynamics control, anti-lock breaking systems and hill-hold control. The working principle is identical to the accelerometer one.
• gyroscopes for vehicle dynamics control.
  The sensing principle is based on the Coriolis force acting on an oscillating mass. An angular rate around an axis vertical to the plane of the chip is capacitively detected by the comb-structure in the center of the chip.
• a new generation of low-cost gyroscopes for roll-over sensing and navigation systems. In case of a rotation around an axis in the plane of the device, an oscillating mass (rotor) will get a torque which is capacitively detected by horizontal electrodes underneath the rotor structure.