Motion has six degrees of freedom: straight line motions in each of the three dimensions, and rotations around three perpendicular axes. Any complex motion of a body can be resolved into a combination of these six elements. The rotational motions are measured by an angular rate sensor, also known as a gyroscope or, simply, a gyro. A gyro is based on Newton's second law, just like an accelerometer. When rotation is added to Newton's equations a mathematical term appears that describes a virtual force called the Coriolis force. Sensing the Coriolis force is the basis of gyro operation. A primary or a seed motion is needed in a gyro; the Coriolis force is the result of an external rotation perpendicular to the seed motion, and is perpendicular to both of them. In MEMS gyros, mechanical vibration is used as the primary motion. A proof mass is brought into angular motion, in this case vibrating angular motion. An external angular rate perpendicular to this motion will cause a force proportional to both the vibration motion and the angular rate. This Coriolis force is detected through synchronized capacitive sensing. Symmetrical structures impart stability to the sensor, as well as reduced cross-sensitivity to linear or angular acceleration. These design features eliminate most of the spurious responses and susceptibility to vibration that plague many MEMS gyro designs. Murata has been able to patent these innovative gyros for both horizontal and vertical sensing axes, providing a distinct competitive advantage.