MEMS is an acronym for Micro Electro-Mechanical Systems. These are ultra-miniature electromechanical devices with overall dimensions in the range of microns, or 1/1000th of a millimeter. While the term MEMs covers a wide range of devices, Murata’s portfolio of MEMS devices currently consists of accelerometers, inclinometers, and gyroscopes, collectively used to sense various types of movements and relative position. These devices are fundamentally based on capacitive sensing. The formula for capacitance is given by epsilon naught times the area of the capacitor plates, divided by the distance between the plates. Epsilon naught is a physical constant. Therefore, if the area of the plates is fixed, the capacitance is proportional to the distance between them. The devices are machined to allow part of the assembly to flex under the influence of acceleration, which consequently changes the distance between the plates of the capacitor. MFI’s MEMS devices are micro-machined from single-crystal Silicon, which is a nearly ideal elastic material. Being nearly perfectly elastic means that the movable part always returns to its original position, even under extreme forces up to 70,000 gs, as well as being flexed billions or even trillions of times. These devices are fabricated using either wet-etch or deep-reactive ion etching processes, both of which are key technologies to MFI. Surface micromachining of polysilicon, used by some other MEMS suppliers, while producing smaller devices, notably exhibits lower stability, higher noise, sticking of the sprung elements affecting accuracy, as well as poor damping resulting in longer settling time. The movement of the sprung mass is essentially constrained within each element to a single dimension, which is termed a degree of freedom, or simply DOF.