A new design of fluidic microdiode is proposed. An initial numerical simula
tion of this so-called vortex microdiode allows us to understand the workin
g principle of the diode. It is shown that the complex relationship between
the inertial and viscous effects may lead to paradoxical results: as an ex
ample, an increase in the viscosity can involve an increase in the flow rat
e. The simulated performances, confirmed by experimental measurements with
a microdiode etched by deep reactive ion etching on a silicon wafer, are co
mpared to the performances of other microdiodes described in the literature
. The efficiency of the vortex microdiode is found to be comparable to that
of the Tesla microdiode, which was the most efficient microdiode. This is
very encouraging, all the more so since the optimization perspectives are v
aried, due to a sophisticated design.