The present book provides a detailed account of the fundamental physics, group symmetry, and concepts from elasticity to establish the general properties of mechanical and electromagnetic wave propagation in crystals. The interaction of mechanical fields and electromagnetic waves in the so-called quasistatic approximation allows to determine the complete set governing equations for applications of piezoelectricity in sensors and actuators. The theory puts strong emphasis to the general allowed forms of material tensors (stiffness, permittivity, piezoelectric stress and strain tensors) for the 32 crystal classes in three dimensions. Piezoelectricity is first introduced using a toy model to emphasize the requirement of non-centrosymmetry of a system for the system to be piezoelectric. The book devotes a chapter to flexoelectricity which is another electromechanical effect that recently has attracted substantial interest in nanostructure applications where strain gradients can be large such as in two-dimensional materials applications (graphene-like materials).

The last part of the book discusses the modern theory of piezoelectric properties using first-principles atomistic calculations and the use of Berry phases. The Berry phase method is a general method that allows various physical properties of solids to be calculated including flexoelectricity. Other atomistic methods for strain calculations such as the Keating model for cubic structures and the Birman-Nusimovici model for wurtzite hexagonal structures are presented. Strain and piezoelectric properties of zincblende and wurtzite pyramidal quantum-dot structures and their influence for electronic eigenstates are discussed by use of the k.p electronic bandstructure method. Following this, optical properties are derived with emphasis to the influence of piezoelectricity. The last chapter of the book presents another subtle effect, sonoluminescence, displaying the mixture of ultrasonics, usually generated by the piezoelectric effect, thermodynamics of fluids, quantum mechanics, and optics.

Key Features:

• Includes an introduction with basic concepts of sound and vibrations
• Presents the fundamental theory of polarization and piezoelectricity
• Explains group symmetry applied to electromechanical system
• Describes piezoelectricity in novel applications such as nanotechnology, optics, and quantum mechanics
• Provides examples and computer code throughout the text