“…In 2019, a new series of modified FOMs was proposed to estimate the effectiveness of a piezoelectric sample under mechanical stress or strain [9], where the modified FOMs associated with the longitudinal and transverse piezoelectric effects were studied numerically for poled porous ferroelectric ceramics. In the same year, porous ferroelectric PZT-type ceramics were used as components of novel laminar composites with 2-0-2 [10] and 2-0-2-0 [11] connectivity patterns, and large values of the FOM (Q33 * ) 2 from Eq. (2) were first achieved and analysed for a 2-0-2-0 composite with two systems of pores.…”