Analysis the Power Converting Performance of Ultrasonically Coupled Piezoelectric Receiver for Three Different Conditions

In this work, designed an ultrasonic wireless power transmission system (UWPTS) for powering implantable medical device (IMD). The parameters such as propagation loss of ultrasonic waves (attenuation coefficient in tissues ∼1dB/cm/MHz), receiver geometry, mode of vibration of receiver, and depth of power transmission have been considered to design efficient UWPTS. The frequency selection of the ultrasonic waves (UW) has vital role in efficient UWPTS design. The higher frequency of UW is not only reducing the receiver size but also reduce the depth of power transmission. Whereas choosing lower frequency increases the receiver geometry. Moreover, the receiver having geometry half of wavelength in the direction of UW propagation can give better electromechanical coupling. The UW having frequencies range 1MHz-10MHz offers wireless power transmission up to 20cm by reducing receiver size in the millimetre scale. Here we considered PZT-5H
$\mathbf{1.1}\times \mathbf{1.1}\times \mathbf{1.5}\mathbf{mm}$
piezoelectric receiver to analysis power conversion performance at three different conditions such as damping (structural loss factor = 0.01), capacitive feed through (50pF), and air gap through PCB (Printed Circuit Board). The generated result shows that the damping and air gap has tremendous effect on power conversion (mechanical power to electrical power) of receiver for the frequency range 0.5MHz to 1.3MHz. At this frequency range, the effect of capacitive feed through is negligible. Though few experimental works have been reported on this system, this is the first COMSOL model to design efficient UWPTS in water by considering the effects of the above three conditions.