*Article* **PIN-PMN-PT Single Crystal 1-3 Composite-based 20 MHz Ultrasound Phased Array**

**Wei Zhou 1,2,3,**†**, Tao Zhang 1,3,**†**, Jun Ou-Yang 1, Xiaofei Yang 1, Dawei Wu 4,\* and Benpeng Zhu 1,3,\***


Received: 27 November 2019; Accepted: 20 May 2020; Published: 21 May 2020

**Abstract:** Based on a modified dice-and-fill technique, a PIN-PMN-PT single crystal 1-3 composite with the kerf of 12 μm and pitch of 50 μm was prepared. The as-made piezoelectric composite material behaved with high piezoelectric constant (d33 = 1500 pC/N), high electromechanical coefficient (*kt* = 0.81), and low acoustic impedance (16.2 Mrayls). Using lithography and flexible circuit method, a 48-element phased array was successfully fabricated from such a piezoelectric composite. The array element was measured to have a central frequency of 20 MHz and a fractional bandwidth of approximately 77% at −6 dB. Of particular significance was that this PIN-PMN-PT single crystal 1-3 composite-based phased array exhibits a superior insertion loss compared with PMN-PT single crystal and PZT-5H-based 20 MHz phased arrays. The focusing and steering capabilities of the obtained phased array were demonstrated theoretically and experimentally. These promising results indicate that the PIN-PMN-PT single crystal 1-3 composite-based high frequency phased array is a good candidate for ultrasound imaging applications.

**Keywords:** PIN-PMN-PT; 1-3 composite; high frequency; phased array
