layer portions of Eccosorb formed by parallel-processing the array elements while still in the form of a unitary piezoelectric block), by using the high-acoustic-impedance flex circuit substrate (e.g., the substrate formed of Upilex-S, Kapton, or other material having an acoustic impedance in the range of 3.5-4.5 MRayls or other suitable range), by isolating adjacent array element 30 by cutting th