The features of the flow potential in the electrolyte that are significant for implementing a liquid acousto-electric converter are presented. The electrochemistry of the flow potential in electrolytes is considered. The peculiarities of the process in the electrolyte solutions associated with the influence of the ion strength of the electrolyte and its dependence on the electrokinetic radius are noted. It is shown that at small values of the electrokinetic radius, the effect of overlapping the electric double layer occurs, leading to a sharp decrease in the absolute values of the flow potential and, consequently, to the practical impossibility of implementing the acoustoelectric transformation. The results obtained can find wide practical application.

In the approximation of a thin double layer, simple dependences of the acoustic fields excited in an electrokinetic electroacoustic transducer on the velocity of the Helmholtz—Smolukhovsky osmotic movement are obtained. From the dependencies it follows that in the absence of losses, when the nonlinearity of the fluid motion equation does not yet affect and there is no turbulent mode of fluid motion in the transducer body, the magnitudes of the amplitudes of the acoustic velocity and pressure linearly depend on the magnitude of the Helmholtz—Smolukhovsky electroosmotic motion velocity.

A new type of microphone is proposed, one of the distinguishing features of which is a variable sensitivity, which depends on the magnitude of the constant electric pumping voltage. In addition, a matching device (mediator) has been created that allows to significantly increase the sensitivity of the microphone. In the course of experiments, a significant increase in sensitivity was confirmed, both due to a charge pump and the use of a mediator. In the course of the experiments, the microphone sensitivity was obtained equal to 1990.5 mV / Pa at 1000 V pumping.

Basing on the analysis of the physical features of the operation of the microphone on electrokinetic phenomena, it has been experimentally confirmed that this microphone works on a functional principle different from the principle of operation of a condenser microphone. It is shown that a microphone based on electrokinetic phenomena can increase its sensitivity by up to about 40 dB due to pumping. Comparison of two experimental studies shows that the sensitivity of an electrokinetic microphone can strongly depend on the size of the porosity of the dielectric placed between the electrodes of the microphone.

A mathematical model of an acoustoelectric transducer based on the use of the electrokinetic phenomenon of the flow potential is proposed. It is shown theoretically that the flow potential increases in proportion to the strength of the constant electric pumping field, which is confirmed experimentally. The described converter has variable sensitivity. Rather large values of the sensitivity of an electrokinetic microphone have been obtained experimentally. The results of the work can be used in the design of acoustoelectric transducers.