Development of non-resonant transducers for ultrasound imaging

An unconventional non-resonant ultrasound transducer design is presented. The design was developed to facilitate fabrication of a single scanhead with fractional bandwidth in excess of 140% and pulse-echo sensitivity adequate for clinical applications. The results obtained from a previously developed theoretical model have been verified experimentally and indicate that a multilayer structure using a 56 micron thick PVDF polymer film can operate in the frequency range from 2-15 MHz. Such bandwidth is not available using conventional, resonant transducer design. The basic design considerations are presented together with the results obtained and discussed in the light of fundamental design limitations. Current efforts aiming at improvements in the technology of the multilayer transducers and the extension of the design as applied to fabrication of super wideband transducer arrays are also discussed.