Aquaporins. In simple terms, these are water channels in the cell wall that allow for H2O molecules to travel in and out of the cell so that the cell won’t swell and explode. Scientists discovered that by using these aquaporins, you can sort out H2O molecules from otherwise impure water. Aquaporins themselves are very small and delicate, so a screen is used and the aquaporins are melted onto the layer of net. Impure water can then be sifted.