fmax 20[kHz] "Maximum frequency"
c0 "343 [m/s]" "Speed of sound in air"
lambda_min c0/fmax "Minimum wavelength"
dvisc 0.22[mm]*sqrt(100[Hz]/fmax) "Viscous boundary layer thickness"
V_DC 1[V] "Bias voltage"
V_AC 0.2[V] "Alternating voltage"
th_pt 400[nm] "Thickness of the Pt layer"
th_au 250[nm] "Thickness of the Au layer"
rho_pt 21450[kg/m^3] "Density of Pt"
rho_au 19300[kg/m^3] "Density of Au"