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Biomimetics Nanoscience and technology ppt


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Biomimetics- inspired from nature

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Biomimetics Nanoscience and technology ppt

  2. 2. WHAT IS BIOMIMETICS? • Biomimetics, is the use and implementation of concepts and principles from nature to creating new materials, devices and systems. • Biomimetics, also known as bionics, biognosis, or biomimicry. • Biomimetics is the adaptation of methods and systems found in nature into synthetic constructs. • Biomimetics evolved because evolutionary pressure typically forces natural systems to become highly optimized and efficient. • Biomimetics, in fact, has its origins back in the times when the Wright brothers modeled their planes on the structure of bird wings; when Joseph Paxton used the design of a lily pad to structure the Crystal Palace. • However the field was only given its official name and definition by Jack Steele of the U.S. Force in the 1960’s.
  3. 3. Art Medicine BIOMIMETICS Architecture Engineering
  4. 4. CATOGARIES OF BIOMIMMICRY Biomimetics is the act of copying nature. Biomimmicry can be broadly categorized under two main topics: • Mimicking mechanisms found in nature e.g. water-proof glue developed with parallel mechanisms found in the study of adhesives produced by mollusks. • Utilizing or incorporating nature itself into novel devices e.g. new strong but light materials have come from studying the structure of bone, Velcro.
  5. 5. NATURE’S NANO • Natural nanomaterials are materials that occur in natural environments, without artificial modification or processing. • Natural nanomaterials are rich in texture and colour created by specific nanoscale structures. • The geometric patterns on seashells, the patterns an colours on butterfly wings, and the shape and texture of birds feathers are a few examples. • The striking and remarkable effects of these natural nanomaterials have inspired artists, decorators and engineers, and scientists.
  6. 6. WHAT TYPES OF NANOSTRUCTURES ARE FOUND IN NATURE? They include inorganic materials such as • clays • carbonaceous soot (think carbon black) • natural inorganic thin films to a variety of organic nanostructures such as proteins and chitin (insect and crustacean shells) • organic structures such as wing ribs and epidermal projections. • These structures lead to a variety of behaviors in nature including the wettability of surfaces, the iridescence of butterfly wings, and the adhesive properties of the gecko foot.
  7. 7. LOTUS EFFECT • The Lotus leaf is an example of a surface, which due to the physical and chemical conditions at the micro- and nanometer scale, is able to produce a self-cleaning effect. • Wilhelm Barthlott, a German botanist, is considered the discoverer of the Lotus Effect as he applied for its patent in 1994. • This effect is the combination of the chemical make-up of the surface and the micro-and nano-projections on the surface. • The protrusions are ~10 μm high with each protrusion covered in bumps of a hydrophobic, waxy material that are roughly 100 nm in height. • The chitin polymer and epicuticular wax projections allow the leaf to trap air. • The water droplets ride on the tips of the projections and resulting bed of air to create a super-hydrophobic surface.
  8. 8. LOTUS EFFECT -APPLICATION • Scientists engineered this behavior with the product Lotusan® - a self-cleaning paint. • This paint mimics the microstructure of the surface of a lotus leaf once it dries and cures in the environment. • Tiny peaks and valleys on the surface minimize the contact area for water and dirt keeping the surface walls clean. • Numerous products are now available that mimic this hydrophobic property including clothing, spray coatings, plungers, bathroom fixtures, automotive parts, etc.
  10. 10. PITCHER PLANT • The unusual surface of these plants features a microtextural roughness that locks in a lubricating layer of water. This water repels oils on insects’ feet, so they slide to their end. • Biofouling -- the build-up of damaging biological material -- is a huge economic issue, costing the aquaculture and shipping industries billions of dollars a year in maintenance. • Since the banning of the toxic anti-fouling agent tributyltin, the need for new non-toxic methods to stop marine biofouling has been pressing.
  11. 11. • The new coating uses 'nanowrinkles' inspired by the carnivorous Nepenthes pitcher plant. • Biofouling can occur on any surface that is wet for a long period of time, for example aquaculture nets, marine sensors and cameras, and ship hulls. • The slippery surface developed stops the initial adhesion of bacteria, inhibiting the formation of a biofilm from which larger marine fouling organisms can grow.
  12. 12. The Nepenthes pitcher plant (left) and its nanowrinkled 'mouth' (centre) inspired the engineered nanomaterial (right).
  13. 13. ARTIFICIAL NACRE • One of nature’s toughest materials is nacre which is the iridescent mother-of–pearl produced by mollusks. • Mollusks create nacre by depositing amorphous calcium carbonate (CaCO3) onto porous layers of polysaccharide chitin. • The structure of nacre resembles a brick wall at the microscopic scale: Calcium carbonate platelets (‘bricks’) alternate with soft biopolymer layers (‘mortar’).
  14. 14. • While the solid platelets serve as the load bearing and reinforcing part, energy can be dissipated into the soft polymer segments. • Together, this results in a light weight material that is considered as both remarkably stiff and tough. • Researchers at many universities are synthesizing biomimetic nanocomposites to create strong materials for use in light-weight armor systems, structures in transportation systems, durable electronics, and aerospace applications, among others.
  15. 15. Formation process of calcium carbonate nanotablets (CCNs) through oriented attachment: small nanoparticles of CaCO3, larger nanoparticles of CaCO3, calcium carbonate nanotablets, and "bricks and mortar" structure of nacre.
  16. 16. BUTTERFLY WINGS • Butterflies are some of the most exquisitely patterned and coloured creatures in the world. • The colours all start with the scales on their wings. • The scales contain crystals called gyroids that are made of chitin, the substance that is also in insect exoskeletons. • These structures are complex and just a few nanometers large— so extremely tiny. • The cuticle on the scales of these butterflies’ wings is composed of nano- and microscale, transparent, chitin-and-air layered structures.
  17. 17. • These multi scale structures cause light that hits the surface of the wing to diffract and interfere. • The diffracted light waves then interfere with each other so that certain color wavelengths cancel out (destructive interference) while others are intensified and reflected (constructive interference). • The varying heights of the wing scale ridges appear to affect the interference such that the reflected colors are uniform when viewed from a wide range of angles. • The specific color that’s reflected depends on the shape of the structures and the distance between them. • This way of manipulating light results in brilliant iridescent colors, which butterflies rely upon for camouflage, thermoregulation, and signaling.
  18. 18. GECKO’S FEET • The gecko foot can adhere to a surface and also release from a surface with ease. • Keller Autumn’s study of the foot has shown that it is covered with micro long projections called setae and each setae is covered with thousands of 200 nm long projections. • The ability of the gecko to climb along walls and ceilings is due to a combination of these very small nano projections finding minute spaces in the surface in which to adhere due to physical electrostatic forces such as van de Waal forces (intermolecular forces) between the foot and the surface. • This study of the gecko foot has led to advancements in adhesives that can be applied and reused. • Fine griped floorings.
  19. 19. VELCRO • One of the older biomimicry examples is Velcro. • Velcro was invented by George de Mestral in 1941 and was inspired by the burrs he found on himself and on his dog. • Being an engineer and entrepreneur, Mr. de Mestral examined the burr under a microscope and realized the small hooks of the burr and loops of the fur/fabric allowed the burr to adhere exceedingly well. • This sparked his idea to mimic the structure as a potential fastener. • The words velours (French for loop) and crochet (French for hook) were combined to start the Velcro company in 1959. Since then, Velcro has become integrated into daily life and has revolutionized the fastener industry.
  20. 20. BIOMIMETICS IN INDUSTRY • The economizing and energy efficient aspects of biomimetics have been adopted in cars as demonstrated by DaimlerChrysler’s prototype bionic concept car.
  21. 21. inspired by the box fish tree growth patterns skeleton structure of blowfish adapted for designing of vehicles DaimlerChrysler’s prototype bionic car
  22. 22. BIOMIMETICS IN ARCHITECTURE • Termites are extremely sensitive to heat, as they live in groups of over 2 million. Even when the external temperature is as high as 40°C, the nests maintain an internal temperature of 30°C. • Mike Pearce from Zimbabwe took note of these characteristics of termites’ nests and constructed Eastgate Centre, the world’s first all-natural cooling structure, in Zimbabwe’s capital, Harare. • This building has holes on the roof and the lower floors to allow natural ventilation, similar to what a termite’s nest does. • Hot air exits through the roof, and the influx of the cold air from the bottom ventilates the building. • Hence, the energy consumption rate of this building is ,10%, and an internal temperature of 24°C is maintained even when the external temperature is
  23. 23. The Eastgate building in Harare, Zimbabwe, adapting the design of nests of termites. Constructed building based on the design of termites’ nest internal structure and air flow of termite nest
  25. 25. THANK YOU