Modeling of the MET Sensitive Element Conversion Factor on the Intercathode Distance

Abstract

MET sensors for measuring motion parameters are used in many scientific and technical fields. Meanwhile, the geometries of the transforming cell applied practically are far from optimal, and the influence of many geometric parameters on the sensitivity has not been studied. These parameters include the intercathode distance in a four-electrode conversion cell. In this paper, a mathematical model that allows calculating the behavior of the conversion coefficient depending on the frequency for a cell with flat electrodes at different intercathode distances is constructed. The stationary current is shown to decrease monotonically with the decreasing intercathode distance at the constancy of other system parameters. At the same time, the signal current decreases in the low-frequency region and increases in the high-frequency range. Taking into account the results obtained, practically speaking, it is advisable to reduce the intercathode distance to the technologically possible minimum, which makes the frequency response more uniform and reduces the current consumed by the sensitive element.

Modeling of the Electrochemical Motion Sensor Conversion Factor at High Frequencies

“…The indicated dependencies correlate well with the previously obtained experimental and calculated data. Experimentally, an increase in the conversion coefficient at high frequencies with a decrease in the cathode-anode distance was observed in [28,32,33], with a decrease in the intercathode distance in [31]. According to [33], the conversion coefficient increases with decreasing thickness of the working channel with other parameters being the same, also in agreement with the results obtained in this work.…”

“…In particular, it can be seen from Figure 5 that the obtained concentration distribution does correspond to the given boundary conditions. Besides, the obtained dependencies qualitatively correspond to the results of calculations performed in [31], which confirm the equivalence of the calculation methods and can serve as a method for verifying a computer code. Equation (29) implies that the signal current is expressed through the distribution of the normal and tangential components of the steady-state concentration gradient.…”

“…The boundary conditions for hydrodynamic Equations ( 1) and ( 2) are no-slip conditions on the channel walls. For Equation (3), a simple boundary condition of zero concentration for the cathodes and the constant concentration on the anodes are used similar to many previously published studies [21,[29][30][31]. Besides, the dielectric boundaries will be considered as non-penetrable for active ions.…”

“…Micromachines 2022, 13, x FOR PEER REVIEW 4 of 16 many previously published studies [21,[29][30][31]. Besides, the dielectric boundaries will be considered as non-penetrable for active ions.…”

“…Calculate the stationary concentration distribution. Similarly to [31], use the Fourier transform method. After the Fourier transform by x coordinate in (6), go to the Fourier component j 0 (k) of the electrical current density j 0 (x) = −2Dq ∂C st ∂z z=0 the concentration distribution can be calculated from the equation:…”