Piezoelectric materials are characterized by several physical parameters that bridge their electrical and mechanical properties.Due to the inherent crystallographic anisotropy of piezoelec-tric materials 83 as well as various types of available vibrational modes, the piezoelectric coefficient tensor is of the third rank and relates second rank mechanical and first rank electrical vari-ables. During operation one of these variables denotes the inputsignal and the other denotes the output signal. The key examples of these properties include piezoelectric charge or strain coefficients (dij), piezoelectric voltage or strain coefficients (gij),electromechanical coupling coefficients (kij), and mechanical quality factor (Qm), which are shown here in reduced notation or Voigt notation.83 Tables 3 and 4 outline a number of applications and their respective figures or merit