In this work, we propose a nanofluidic diode for simple fluids using non-uniform
nanochannels. Molecular dynamics simulations show that the fluidic diode allows water
flows in the forward direction and blocks flows in the backward direction in a wide range of
pressure drops. The unidirectional water flows are owing to the distinct activation pressures
in different directions. In the forward (converging) direction, the activation pressure is small
because of the relatively low capillary pressure and the water coalescence at the exit. In the …