Fig. 1.

SEM micrographs of unetched CTL (1A and 1B) showing effects of polishing; and the HTE surface (1C and 1 D) displaying hierarchal nanotopography (scale bar for Fig. 1A–D ​= ​500 ​nm). The inset image in 1 D shows the morphology of a single nanostructure at 200 ​K magnification (scale bar ​= ​100 ​nm). AFM-3D reconstructions showing nanotopological features of a 5 ​× ​5 ​μm region on CTL (1E) and the superhydrophilic HTE surface (1F) (scale bar ​= ​1 ​μm). The bar graph represents the water contact angle for CTL and HTE surfaces mean ​± ​SD (n ​= ​3), p ​= ​0.0003. Images above the bar graph demonstrate the wettability by the sessile drop method (1G). Nanostructure measurements, AFM and wettability can be found in supplementary information Table S1.