Currently, the application of microstructures on the surface of materials is being one of the most used strategies to get them to acquire new properties. Did you know that these types of microstructures come from the surface of living beings? We explain it to you in this blog!
What are biomimetic materials?
Biomimetic materials simulate the best ideas of natur. They use the structures or forms of nature for the benefit of human beings. Biomimetics aims to learn how nature has been able to generate solutions, allowing living beings to adapt to their environment.
Types of biomimetic materials
The diversity of characteristics of the elements of nature provides us with an inexhaustible source of resources to produce materials with fascinating properties whose efficiency has been proven. For decades, researchers from all branches of science have had the objective of replicating the behavior offered by some materials from nature due to their potential applicability in construction, aesthetics, safety and medicine, among other fields.
The three types of surfaces, which include superhydrophobic, superoleophobic and superhydrophilic, allow materials to be endowed with properties such as low adhesion, anisotropic wetting, antireflection, directional adhesion, antifouling, photocatalysis, self-sterilization, and antifog, among others.
Example of biomimetic materials and their applications
The development of these surfaces has been based on the understanding of the structures of the surfaces that many living beings present, such as the shell of a snail, the skin of a shark or the wings of a cicada. All of them have characteristics that could be very useful in certain materials. One way to make these structures in different types of materials is the use of laser technology.
Tortoise shell surface
The surface of a snail’s shell exhibits self-cleaning properties. The shell of the snail consists of a compound of aragonite and protein, and the upper surface of the shell is covered with a layer of protein. The surface of the snail shell has a rough structure consisting of line grooves with a pitch of 0.5 mm and 0.1 mm. Consequently, it was revealed that the key to the self-cleaning property of the snail shell is its superhydrophobicity; that is, the surface is barely wet. Inspired by the snail shell, biomimetic materials such as ceramic tiles have been built, as well as sanitary accessories such as those for toilets, kitchens and bathrooms.
Shark skin surface
Sharkskin is a typical pattern for self-cleaning and low-adhesion surfaces. Shark skin contains very small, tooth-like individual scales called dermal denticles, which are covered by specially-sized rivets and spaced oriented parallel to the swimming direction. When sharks swim fast, during turbulent flow, vortices form on the surface, causing high shear stress across the entire surface. The rivets lift the high-speed vortices from the surface, exposing only the tips of the rivets to high shear stresses. As a result, drag is decreased and the shark can swim quickly and efficiently through the water in a turbulent flow regime.
Artificial shark skin surfaces have been developed for applications such as swimwear, ship hulls, aircraft, and wind turbine components. We leave you an example of these biomimetic materials that have been carried out at ATRIA Innovation.
Cicada wing surface
The external surfaces of insects have attracted attention due to their various intelligent functions, such as the self-cleaning property of cicadas’ wings. The wings of the cicada consist of hexagonal nanopillars whose separations vary from 110 nm to 140 nm. The height of the pillar structure from top to bottom ranges from 225 nm to 250 nm. Due to the nanoscale matrix and waxy coating of the pillars, cicada wings show superhydrophobicity. Therefore, the contaminants on the surface are easily removed with water in a manner similar to that of a lotus leaf. One of its main applications is in the development of antibacterial surfaces, since they prevent the development of bacteria on the surface. This type of surface is widely used in medical and surgical equipment and packaging.