Three-dimensional printed liquid diodes with tunable velocity: Design guidelines and applications for liquid collection and transport

Directional and self-propelled flow in open channels has a variety of applications, including microfluidic medical devices, industrial filtration processes, fog-harvesting, condensing apparatuses. Here, we present versatile three-dimensional-printed liquid diodes that enable spontaneous unidirectional over long distances for wide range contact angles (CAs). Typically, can achieve average velocities several millimeters per second distance tens to hundreds millimeters. The have two key design principles. First, sudden widening the channels' width, combination with small bump, pitch, ensure pinning backward direction. Second, an adjustable reservoir differing expansion angles, bulga, is introduced manipulate velocity. Using experiments lattice Boltzmann simulations, provide comprehensive analysis behavior speed within depending on CAs, pitch heights, bulga angles. This provides guidelines fabrication bespoke optimal their potential applications. As feasibility investigation, test our condensation water from fog subsequent transport uphill.