Mems apparatus

A MEMS (microelectromechanical systems) apparatus comprising:

• a substrate comprising first electrodes, second electrodes, a first region, a second region, and an etched area, the etched area located at the center of the substrate, the first region and the second region opposite each other, the first electrodes equidistantly located in the first region, the second electrodes equidistantly located in the second region;
• a proof mass disposed at the center of the substrate and comprising third electrodes, fourth electrodes, a first edge, and a second edge, the first edge and the second edge opposite each other, the third electrodes equidistantly located on the first edge, the fourth electrodes equidistantly located on the second edge;
• and
• beams respectively disposed between a periphery of the substrate and a periphery of the proof mass and configured to support the proof mass so that the proof mass and the substrate are a first distance apart;
• wherein each of the first electrodes, parallel to an axis, extends along the axis towards the first edge from the first region by a second distance, and each of the third electrodes, parallel to the axis, extends along the axis towards the first region from the first edge by a third distance, the first electrodes and the third electrodes opposite to and interlaid with each other, the second distance and the third distance greater than half of but no greater than the first distance;
• wherein each of the second electrodes, parallel to the axis, extends along the axis towards the second edge from the second region by the second distance, and each of the fourth electrodes, parallel to the axis, extends along the axis towards the second region from the second edge by the third distance, the second electrodes and the fourth electrodes opposite to and interlaid with each other.