Fabrication of micro-ultrasonic phased array electrode via electric field-driven printing method

Abstract

The electrode is an important part of a micro-ultrasonic phased array, commonly fabricated by magnetron sputtering technology. However, with the expansion of the application field, the structures of the phased arrays are becoming more complex, making the traditional magnetron sputtering method no longer applicable, and the realization of micro-scale phased array electrodes by direct printing technology still faces great challenges. Herein, an electric field-driven direct printing method was proposed to fabricate micro-ultrasonic phased array electrodes. The influence of sintering parameters on the resistivity and the effect of printing parameters on the geometric size and surface morphology of the electrode were comprehensively explored, and the mathematical model between the electrode line width and the printing parameters was established. The final printed electrodes exhibit superior properties with a resistivity of 2.4×10-7 Ω·m, a surface roughness range of 460-550nm, and a line width range of 125-480µm. Additionally, a micro-scale electrode was printed on the piezoelectric ceramic with PZT-5 as the material, and after polarization treatment, the piezoelectric coefficient can reach 405 pC/N, which proves that this method can be applied in the field of fabricating phased array electrodes.