Wetting Properties of Natural and Plasma-Processed Biomimetic Surfaces - Biomimetic Architectures by Plasma Processing - page 130

Table 4.1 Functions of surface macro-, micro- and nanostructures in

various biological objects

Surface Structure and order

of size

Properties Function

Papillae approximately
10 mm;

Contact area Self-cleaning

Lotus leaf

Wax crystals more
than 1 mm

Air retention

Scale approximately
5 mm;

Structural
strength;

Marine
antifouling;

Papillae approximately
100 mm;

Contact area; Defense against
marine organisms

Fish scale

Nanostructure
approximately 100 nm

Water
retention

Setae approximately
50 mm;

Structural
strength;

Water resistant;

Pond skater

Nanogrooves
approximately 100 nm

Air retention Strong support-
ing force

Barbs; Structural

strength;

Keep birds dry

Bird (dove)
feather

Barbules Air retention

Scales approximately
1 mm;

Structural
strength;

Low friction

Sand skink

Nanothresholds
approximately 100 nm

Electrostatic
repulsion

4.4 Adhesion Properties of Surface

A super-repellent (super-hydrophobic) surface generally displays
very high CA (typically >150°) and very low CAH (typically <5°)

for a contacting liquid. But super-hydrophobic surfaces may also
display a high CA and high hysteresis, and as a result we may
observe near-spherical liquid droplets that instead of rolling-off
stick to the surface. Super-hydrophobic surfaces are no longer