Conformally Large-Area Single-Crystal Piezocomposites with High Performance for Acoustic Transducers

Abstract

Large-area and conformal piezoelectric elements are highly desired for acoustic transducers to possess a large power source level and wide detecting range. To date, single-crystal piezocomposites attract much attention on enhancing the power source level and bandwidth for next-generation acoustic transducers, owing to their higher piezoelectric and electromechanical coupling properties compared to traditional piezocomposites. Unfortunately, it is still challenging to achieve large-area and conformal single-crystal piezocomposites because of the fragile nature, large anisotropy, and the limited grown size of piezoelectric single crystals. Here, we successfully fabricate the conformally large-area single-crystal piezocomposite with an area of 160 × 50 mm 2 and a bending angle of 162°by a modified 3D-printingassisted inserting method. The single-crystal piezocomposite exhibits a high thickness electromechanical coupling factor k t of 85% and a large piezoelectric coefficient d 33 of 1150 pC/N, surpassing those of the reported large-area piezocomposites. The influence of the volume fraction and curvature radius of single-crystal PCs and acoustic transducers was investigated. Furthermore, we designed an acoustic transducer based on the conformal single-crystal piezocomposite. Benefiting from the excellent piezoelectric and electromechanical properties of the single-crystal piezocomposite, the transducer indicates a high maximum transmitting voltage response of 171.8 dB. Especially, its bandwidth (−3 dB) achieves 60 kHz with a resonant frequency of 292 kHz, which is about 1.8 times superior to the conformal acoustic transducer based on the ceramic piezocomposite with a similar resonant frequency. This work may benefit the future design and fabrication of high-performance and complex-shape piezoelectric composites as key materials for next-generation transducers.

An Emerging Era: Conformable Ultrasound Electronics

“…[130] Li's group modified the 3D-printing-assisted inserting method to achieve large-area and conformal single crystal piezocomposites (Figure 4a-d). [131] The single-crystal piezocomposite exhibits a high k t of 85% and a large d 33 of 1150 pC N −1 with a bending angle of 162 o , which will benefit the future design and fabrication of high-performance and complex-shape piezoelectric composites as key materials for cUSE. Besides the single flexible elements, 1-3 composites have also been fabricated as the array, which can conform to irregular surfaces to obtain precise images.…”