Abstract: Biomimicry has many potential benefits as many
technologies found in nature are superior to their man-made
counterparts. As technological device components approach the micro
and nanoscale, surface properties such as surface adhesion and friction
may need to be taken into account. Lowering surface adhesion by
manipulating chemistry alone might no longer be sufficient for such
components and thus physical manipulation may be required.
Adhesion reduction is only one of the many surface functions
displayed by micro/nano-structured cuticles of insects. Here, we
present a mini review of our understanding of insect cuticle structures
and the relationship between the structure dimensions and the
corresponding functional mechanisms. It may be possible to introduce
additional properties to material surfaces (indeed multi-functional
properties) based on the design of natural surfaces.
Abstract: Two different superhydrophobic surfaces were
elaborated and their oil repellency behavior was evaluated using
several liquid with different surface tension. A silicone rubber/SiO2
nanocomposite coated (A) on aluminum substrate by “spin-coating"
and the sample B was an anodized aluminum surface covered by
Teflon-like coating. A high static contact angle about ∼162° was
measured for two prepared surfaces on which the water droplet rolloff.
Scanning electron microscopy (SEM) showed the presence of
micro/nanostructures for both sample A and B similar to that of lotus
leaf.
However the sample A presented significantly different behaviour
of wettability against the low surface tension liquid. Sample A has
been wetted totally by oil (dodecan) droplet while sample B showed
oleophobic behaviour. Oleophobic property of Teflon like coating
can be contributed to the presence of CF2 and CF3 functional group
which was shown by XPS analysis.