Fig. 3

a Schematic illustration of upright confocal laser scanning microscopy of 3-D nFH arrangements with a water-dipping lens. CLSM images of b 1.0 wt% drop-coated, c 0.1 wt%, d 0.5 wt% and e 1.0 wt% bar-coated nFHs on glass substrates; 3-D-perspective reconstructed (left), upper-part (upper right) and lower-bottom-part (lower right) z-stack images of nFHs. Occupied area of nFHs f at the upper of a substrate and g at the bottom of a substrate, respectively. Z-stacked directionality of h 1.0 wt% drop coated, i 0.1 wt%, j 0.5 wt% and k 1.0 wt% bar coated nFHs on glass substrate