A history of medical and biological imaging with polyvinylidene fluoride (PVDF) transducers

Polyvinylidene fluoride (PVDF) is a ferroelectric polymer with unique prope rties suitable for use in a wide range of medical and biological imaging ap plications. Most notable among these is its low acoustic impedance, which m atches that of the body reasonably well, and its flexible mechanical proper ties. This paper traces the exploitation of PVDF as a transducer material f rom its early beginnings for thyroid and breast imaging to its current well -established applications in ultrasound biomicroscopy. Although PVDF's elec tromechanical properties fall short of composite ceramic materials in the t raditional diagnostic frequency range, it has significant advantages in the 25- to 100-MHz range. Design criteria for high frequency transducers are r eviewed, and examples of relevant medical and biological images are used to illustrate the excellent image quality obtained with this remarkable mater ial.