Ultrasonic transducers are key components in sensors for distance, flow and level measurement as well as power and other applications of ultrasound. This book reviews recent research in the design and application of this important technology. Part one provides an overview of materials and design of ultrasonic transducers. It explores piezoelectricity and basic configurations, along with electromagnetic acoustic transducers, and the use of ceramics, thin film and single crystals. Part two investigates modeling and characterization and considers in detail performance modeling, electrical evaluation, laser Doppler vibrometry and optical visualization. Applications of ultrasonic transducers are the focus of part three, beginning with a review of surface acoustic wave devices and air-borne ultrasound transducers and goes on to consider ultrasonic high temperature and flaw detection systems, power, biomedical and micro scale ultrasonics, therapeutic ultrasound devices, piezoelectric and fiber optic hydrophones, and ultrasonic motors.