Surface Micromachinable Accelerometer using Fringe Electrical Field of Penetrating Ferroelectric Substrate and its Characterization

This paper reports fabrication and characterization of a high sensitive surface micromachinable accelerometer using ferroelectric material having a large dielectric constant, such as bulk PZT (epsiv_r = 2600). The measuring principle is based on detecting capacitance change with respect to the dielectric mass movement in the fringe electrical field. High sensitivity of several sub pF/g is confirmed, which is increased several hundreds times compared with author´s previous sensor using polymer Parylene (epsiv_r = 3.15). It is proven that the accelerometer bandwidth is much lower than the mechanical resonant frequency of the Parylene structure by FEM simulation and experimental investigation, the reason of which is also discussed.