A High Fill-Factor High Density Large PMUT Phased Array

A PZT-based high fill-factor high density large PMUT array is designed and fabricated with 64 array elements and integrating a total of 15360 PMUT cells (cavity size 85μm). The impedance test result indicates that the device exhibits a resonant frequency of 4.2 MHz in vacuum. In the hydrophone measurements, the average sound pressure of one single channel of PMUT array is 9.08 kPa in water at the distance of 6mm with a input of 10Vpp. A broad -3dB-bandwidth(5.2MHz) is observed which is 176% of the center frequency. After implementing necessary signal filtering and amplification, high-contrast imaging of the sheep-spine in the phantom is obtained. The results affirm the array's potential in ultrasound imaging, particularly highlighting its significant promise for future applications in human body imaging.