Elastic flexural and longitudinal waves can be generated in structure by using piezoelectric transducers. These waves may be used to obtain fundamental properties of the medium or to locate flaws. Bulk waves can be created in a thin piezoelectric plate by applying an electrical signal to interdigital electrodes deposited on each side of the plate. These transducers can be used to generate ultrasonic bulk waves with a wide range of frequencies and amplitudes controlled by a number of electrodes and a delayed voltage independently applied to each electrode. Numerical results demonstrating the finite element simulation of piezoelectric actuators and sensors in generating and detecting elastic bulk waves are presented. Experimental observations of flexural waves generated hy surface mounted piezoceramic plates are compared with the finite element results. Bulk wave generation and detection using interdigital electrodes are simulated and their potential application as probes in smart structures is discussed.