Thin, flexible, and biocompatible medical ultrasound array transducer using a sol–gel composite spray technique

Abstract A thin, flexible, and biocompatible medical ultrasonic transducer was developed using a sol–gel composite spray technique to fabricate a single sheet of piezoelectric material. The careful selection of materials prioritized flexibility, with silicone rubber being chosen for its biocompatibility as the material to be in direct contact with the living body. A porous lead zirconate titanate film with a dielectric constant of 134 was generated, and comb-shaped electrodes were printed on the piezoelectric film to form a 64-channel linear array, which successfully suppressed crosstalk values between adjacent elements and at a distance of two elements to −41.5 and −45.8 dB, respectively. Experiments using string targets achieved a spatial resolution of 2 mm in the lateral direction and 0.68 mm in the axial direction. In an imaging experiment of the carotid artery, the transducer was successful in visualizing the vessel wall before and after the carotid artery vessel.