چكيده به لاتين
Acoustic wave front control has many industrial and medical applications such as nondestructive, endocrine therapy, imaging and drug delivery. Several methods have been proposed to effective control acoustic waves, such as the use of Hifu, acoustic metamaterials, acoustic lenses and piezoelectric arrays. One of the best methods that have the ability to control the wave front is piezoelectric arrays, they are able to generate and manipulate various types of sound wave fronts. In this research, we first design and simulate an ultrasonic phased array by piezoelectric generators in a water medium for concentrating the sound wave front. At the beginning, the phased array is carefully designed in the time and frequency domain to have the highest accuracy in concentrating the sound wave. Lead titanate zirconate is used for piezoelectric array and acrylic is used as a buffer to increase the efficiency of the designed model. The effect of number of arrays and Gaussian pulse width on focus quality was investigated. The performance of the array is evaluated at different angles such as 15 and 30 degrees (positive and negative). In the next step, we examined the frequency domain and the effective parameters in the design at the frequency of 2.5 MHz. Finally, by using of the radiative acoustic force created by the focused wave, the polystyrene microparticle is manipulated. This force is obtained by the gradient of sound pressure between the focus point and surroundings. It should be noted that the planar wave will be able to move particles with a large diameter of about 50 microns, while the designed model can reduce this diameter to 5 microns, which can be used in drug delivery. The maximum displacement of a particle with a diameter of 5 microns is equal to 0.46 mm, which can be increased to 1.84 mm toward the right or left with 4 displacement steps
