Forty-channel phased array ultrasonic probe using 0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO3 single crystal

A 0.91Pb(Zn1/3Nb2/3)O-3-0.09PbTiO(3) (PZN-PT) single crystal with high electromechanical coupling factor (k(33)) > 90% has been used to fabricate a 40-channel phased array ultrasonic probe with greater sensitivity and broader bandwidth than conventional probes. This probe has a center frequency of 3.5 MHz and an aperture of about 6.0 x 7.5 mm. The standard probe fabrication process was modified for PZN-PT. The dispersion of echo signals was within +/- 20% of the mean value. After recovery poling, the echo amplitude of the PZN-PT single-crystal probe is 8 and 5 dB higher than that of one- and two-matching-layer PZT probes, respectively. Moreover, the fractional bandwidth of the single-matching-layer PZN-PT probe is broader than that of the two-matching-layer PZT probes. The PZN-PT single crystals provide great improvements in the sensitivity and bandwidth of phased array probes.