Present a procedure and fabrication of linear phased array ultrasonic for focusing waves in low frequency

Applying ultrasonic phased array transducers has been widely recognized through fault detection and inspection, underwater telecommunications and medical studies due to their uniquely significant properties. One important capability is wave focusing. The main objective in this study is focusing ultrasonic waves using linear phased array transducers. The environment in this research is water. Design and fabrication of these transducers is done in both mechanic and electric sections. First, dimensions of the transducers in terms of their number, size and arrangement elements were determined. The linear arrangement including 8 piezoelectric disks was checked. Based on piezoelectric shape modes, 46 kHz was determined as the appropriate operating frequency for the transducer. Afterwards, the appropriate algorithm for piezoelectric stimulation, backing material and their size in addition to the matching layer were determined; accordingly, simulation and verification of the design and estimation of transducer behavior were applied. Hence, assembly and construction stages of the transducer were done. Electric design includes the design and construction of control and power circuit to stimulate phased array transducers. The constructed transducer’s behavior including acoustic pressure measurement in terms of different height levels of the transducer, piezoelectric stimulation voltage influence and each element influence on acoustic pressure in focused area was experimentally studied. Hydrophone was used to determine the acoustic pressure. Results indicate that one of the most important factors about wave focusing is the number and displacement of the elements. Polyurethane was the most proper choice in phased array transducers due the problems of using PVDF as matching layer. Concerning disk piezoelectric with high diameter proportion rather than high thickness, first radial modes are the proper choice for the transducer’s shape mode. The experimental tests confirm the transducer’s behavior evaluation correctness in terms of the design, extracted algorithm and also the simulation.