Natural life has 3.8 billion years of research and development behind it
For more than 3.8 billion years, Life on Earth has conducted continuous experimentation with materials, structures and processes. Today like yesterday, the best ideas on the planet are those that work and save energy and materials.
Whatever the challenge that engineers, physicists and chemists and craftsmen face, the chances are high that one or more of the world’s 30 million living creatures, not only have already faced the same challenge but have already evolved effective strategies to solve it and thrive .
Bormawachs believes that the disciplines of biomimetics, bionics and biodesign offer valuable help in solving problems and improving materials and production processes. There are many examples of which man has managed to understand the principle of operation, and to build objects that simulate and replicate its effectiveness and efficiency.
In the 1990s Wilhelm Barthlott, Plant Science teacher at the University of Bonn, studied leaves of the lotus plant (Nelumbo nucifera). Looking at the surface under a microscope, Barthlott discovered that these leaves have a particular surface structure, they are not smooth and compact, but have protrusions on the nanometer scale. This nanostructure is responsible for the super-hydrophobicity effect, the water is not absorbed but forms almost spherical drops (there is a high surface tension). When it rains, the single drop rolls on the surface, trapping and taking away dust and foreign substances. Barthlott’s idea is today applied industrially and marketed in a series of products, under the brand name “LOTUSAN” “self-cleaning coating for facades of houses and buildings.
Nature has taught us many things about the reduction of the reflection phenomenon that occurs when light travels from one medium to another with a different reflection index, such as air and glass, a problem encountered in solar panels, monitors and screens. , photographic lenses, shop windows, etc.
The anti-reflection phenomenon observed in the cicada wing, dragonfly wing, moth eye and butterfly wing has inspired many powerful biomimetic materials. The operating principles are: the creation of multiple nanostructured layers (refractive index gradient), nanoporous layers (capable of trapping air) or a 3D structure of nanocones capable of trapping light. For example, the tightly compacted hexagonally protuberances observed in cicada wings exhibit a combination of anti-reflection function and hydrophobicity. The nanostructured surface on the eyes of insects, especially hawk moths, allow viewing in the dark and catching very little light.
The random nanostructures in the wing of the glass butterfly guarantee a very high degree of transparency, such as to produce an almost invisible wing. Great efforts have been made to reproduce the nanostructures present in these biological surfaces, however the differences between the nanostructures of natural origin and artificial reproduction are evident.
Application examples is CANON’s Subwavelength Structure Coating (SWC) treatment, a lens coating technology that minimizes flare and ghosting caused by reflected light.
Another example is the Pilkington OptiView a monolithic glass, with anti-reflective coating on a surface. Pilkington / Nanofilm hybrid anti-reflection coating – White paper Kieran J. Cheetham, Neil McSporran, Krish Rao, Stephanie L. Castro 1NSG European Technical Center, Hall Lane, Lathom, L40 5UF, UK, www.pilkington.com
In 1941 a tear-off closure system was patented by the Swiss engineer George de Mestral. Inspired by the burdock flowers that get caught in the clothes and fur of the animals, thanks to the hooked system of the dried flower petals.
The Swiss engineer noted that each petal had a microscopic hook at the top, which allowed reversible joints, comparable to the crochet technique that “catches” and “releases” the thread. From the observation of this phenomenon he designed strips of “crochet” in nylon combined with strips of fabric, capable of generating a reversible interlacing mechanism. The “Velcro” was born, an acronym for the words VELvet and CROchet.
Throughout history, architects, engineers and designers have designed structures drawing inspiration from natural forms.
For Leonardo da Vinci (1452 – 1519) Nature was an indispensable source of imitation for his creations: through in-depth studies on the anatomy of birds, he laid the foundations for the development of a Flying Machine, an ornithopter, an aircraft with a winged surface , whose complex mechanism simulated the structural principles of bird wings.
In times closer to us, the architect and botanist Joseph Paxton, applying the biomimetic theories, designed the roof of the Crystal Palace in London, a building from 1854. The functional principles were inspired by the Victoria Amazonica plant, with the aim of creating a structure lightweight lattice, in steel and glass, to maximize lighting and solar heating.
Building with thermal self-regulation
The termites’ autonomous and natural ventilation system uses thermal excursion to regenerate an isolated environment, the temperature of which remains almost constant despite the torrid daytime heat and the fresh of the night.
The EastGate Center project in Harare, Zimbabwe, created by architect Mick Pearce was built and despite the climate of the place where it is located, it does not have any conventional ventilation system.
For its realization, the principles of self-regulation and natural ventilation observed in the characteristic pinnacle nests of African termites have been applied. In this way the Eastgate Center uses a natural air conditioning system uses at least 10% less energy in a building of that size normally consumed.