Figure 13.
a,b) Schematic of floating‐coffee‐ring‐driven assembly method. Reproduced with permission.[ 162 ] Copyright 2016, Wiley‐VCH. c) Schematic of unidirectional coating driven by evaporation and droplet undergoing coffee ring effect. Reproduced with permission.[ 163 ] Copyright 2016, American Chemical Society. d–f) Pen‐writing technology. Reproduced with permission.[ 164 ] Copyright 2017, the Royal Society of Chemistry.