Аннотация:An overview is given of the results of recent and new studies by the authors of this work on topics related to backward acoustic waves of pure-shear type and Lamb type in piezoelectric, crystal, and isotropic plates with free and liquid-loaded surfaces. Various physical mechanisms giving rise to such
waves are revealed and quantitatively described by the use of asymptotic expansion of the secular equations and the perturbation theory. The peculiarities of properties of leaky backward waves are considered. The possible applications of backward waves in microelectronic devices (such as sensors et
al.) are discussed.