The wax screen-printing method was used to fabricate the patterned paper (Figure S2) as previously
described [42]. The filter paper was positioned on the hot plate at 100 °C, and then solid wax was
placed on the block screen. After the wax was melted, it was printed through the perforated screen and
allowed to absorb into the paper. The patterned paper was ready to use after the wax was cooled to
room temperature.