The plate wave element possesses superior frequency temperature characteristics.

The probe includes a transducer which generates a localized ultrasonic Lamb wave.

The attenuation of a Lamb wave and a compressional wave is used to determine a presence of a micro-annulus between the casing and the cement.

An acoustic touch position sensor is shown wherein a Lamb wave is imparted into a substrate by a transducer mounted on the substrate, the lamb wave propagating along a first axis.

The apparatus and method provide for the propagation of an axi-symmetric Lamb wave of a single mode in one direction along the pipe.

A dual mode lamb wave resonator including a piezoelectric layer, first and second electrodes having first and second pluralities of electrode fingers.