Ferroelectric nylon-7,-11 ultrasonic transducer performance

Measurements of the high frequency electrical and acoustic properties of ferroelectric nylon 7 and 11 are reported for frequency and temperature ranges of interest for ultrasonic transducer applications in medicine and nondestructive testing. The dielectric properties of the samples were measured over a broadband frequency range (typically 1-100 MHz), including the fundamental half-wave resonance frequency for the sample, and the properties of interest for ultrasound transducer design were determined using a curve-fitting resonance technique. These properties were then used in a computer simulation program to assess the acoustic performance of nylon-based ultrasonic transducers and compare them with PVDF and P(VDF-TrFE) copolymer designs. Comparisons were carried out on the pulse-echo acoustic performance including pulse width, sensitivity, insertion loss, and bandwidth. Finally, a nylon ultrasound transducer was fabricated for pulse-echo acoustic performance measurements and comparison with PVDF. Tests verified the broadband acoustic performance of nylon 7