Figure 3 . Images of the AMPH device at 1x (left), 20x (center), and 235x (right) magnification. The width of the octagonal device is 27 mm. The column is comprised of an internal solid framework surrounded by a solid outer shell. The framework is built of porous walls that are ~150 μm thick. The framework has a hexagonal honeycomb-like structure, and in the vertical direction it follows an undulating pattern to minimize the possibility of liquid droplets falling through the device without interacting with the wicking structures. This undulation generates the wave-like surface of the outer shell (Figure 1 (C)).
The column was first designed in CAD software (SolidWorks 2019) and then manufactured via an additive printing process that employs direct metal laser sintering: a laser melts metal powder one layer at a time, gradually building on previous layers until the entire structure is completed. The internal honeycomb is a high-porosity metal scaffold created by scanning the laser quickly and at a heat intensity that is too low to completely melt the metal powder. The solid outer shell is made with laser power and scan settings that produce high-density, non-permeable metal. The manufacturing was performed by i3DMFGTM and printed with nickel-based Inconel 625 using custom print settings.

Distillation System

The distillation system consists of a microchannel recuperator to precool the incoming air, a custom condenser that attaches to the cold head of the stirling cryocooler, the distillation column, and a vacuum can that contains these components and provide thermal insulation. The same vacuum can, condenser, and recuperator were used for all experiments, with the distillation column being changed for each set of tests. The system configuration is shown in Figure 4.