Piezoelectric transducers for medical ultrasonic imaging

The requirements of a transducer for diagnostic applications are illustrated with specific examples, and the material parameters that influence transducer design are discussed. The current status of piezoelectric transducer design and common approaches taken to improve the design are also presented. The acoustic and electrical impedance criteria that must be satisfied in order to design an ultrasonic transducer with broad bandwidth response are described. It is pointed out that the development over the past decade of several different types of composite materials, PVDF (polyvinylidene fluoride) based copolymers, piezoelectric ceramics with low transverse coupling, and electrostrictive materials offers opportunities to overcome some of the compromises involved in transducer design.<
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