Periodic crack-model of comb transducers: excitation of interface waves

A model for a comb transducer is proposed and analyzed. It
is shown that interface waves are generated in the comb-sample contact area. The
interface waves are leaky waves that transport acoustic energy along the
interface towards the comb edges, where it is eventually converted into surface
acoustic waves propagating outside the comb. By including piezoelectric effects
in the comb and the sample materials, it is possible to analyze the incident
bulk wave generated by embedded metal strips on both sides of the interface.
Approximations for the scattered wavefield and the relationship describing the
energy transfer along the interface are derived. Numerical examples are
presented.