Learning from Nature: Advanced Biomimetic Materials | Panče Naumov || Radcliffe Institute
Thank. You Meredith. I. Have, been waiting for this introduction, it was simply amazing thank you very much. In. A recent survey I was asked, to describe. Ratcliffe. In five words and this. Might look like an easy question to answer but, they soon realized it was quite challenging because, there are so many words that come to mind. Encouragement. Support diversity. Inclusion, recognition. Inspiration. Motivation, uplift. Elevation, many. Of these universal, values align with the history that happened between these walls and I reflected in the mission of the Institute. Radcliffe. Is intellectually, rigorous urban. In location, bold, in spirit, and global in Outlook, Radcliffe. Is about big and important, issues, in ideas, like peace and governance, health and equity are, resources. And tolerance, ratliff. Transforms, and lightens and empowers, I would, like to highlight. That. Working in this academic constellation. Has been an immensely, intellectually. Uplifting, professionally. Rewarding and, personally, transforming, experience. To. Be ugly fellow is both the great honor and a privilege and, I can't express how grateful I am to the leadership, for. Giving him for, giving me this opportunity to, be part of this I would. Also like to take this opportunity and highly recommend, to my fellow researchers, from Natural Sciences to apply for this fellowship and to, advance professionally in, a supportive, stimulating, and very dynamic setting, as. Meredith. Mentioned, I come with a cross-cultural, experience, and throughout. My two decades, of academic, career I learned, to appreciate both, the benefits, and challenges of, culturally, and socially, very, diverse academic settings, I was. Born and raised in Macedonia, a beautiful country with a very rich and long history in, southeastern. Europe but also a place which appears to be constantly, in transition, I spent. Half of my professional, career in Japan in, an academic environment which, is in many ways established. In advance but. Which is also generally viewed as rather rigid, and conservative, I now. Work for New York University, in their portal campus located in the Emirates where, one of the best private American universities. Has set as its mission to, partake, in the process of transforming, an outward. Authoritarian. Society, within a very short period, of time I. Also. Happen to be the only chemist, in this batch of fellows and when I was thinking about. The subject of this talk the chemist in me was tempted, to show you something. Like this, I. Can. Lend you a few slides of this sort if you ever suffer, from insomnia to, help you with the sleep. But. In attempt to avoid. Being technical, instead I wanted to take you on a journey and tell, you about something, all of us can relate to something, that also continues, to inspire great. Scientific, discoveries I ask. Myself what. Is that these so different, cultures, that I have experienced. Have in common in. A recent interview for, one of the scientific journals, I stated that there, are two things that inspired, me to become a scientist, first, the curiosity, and second, the nature I recognized. Very early in life that full the, full word and beauty of nature instead, my very first recollections, of my early childhood are, those of the beautiful green hills of Macedonia, where, I was both curious and inspired about how plants. And animals live and survive I later. Discovered that, endorsing. Cognitive, connectedness, to nature and engaging with natural beauty is not only common for many cultures regardless, of their social and political milieu, but at, an individual, level it is also thought to be associated with greater well-being and, awareness, for environmental.
Conservation And, that, idea is perhaps best, sublime in this quote of John F Kennedy that. You can find on a board in the Kennedy Memorial Park, right here in front of Harvard, but. Nature also has a quirky, unexpected. Or just, downright, weird sight, geckos. Can climb up walls and stick to ceilings. Insects. Can walk on water and some snakes can even fly these. Obscure corners of the living world might sound like an episode of the Ripley's Believe It or Not yet, they happen more often than we think about them, and more importantly, they may hold enormous, benefits, to the humanity. Over. The course of millennia plants, and animals have developed and perfected mechanisms, for motion survival. And dispersal, with astounding grace, speed and versatility, but. How do they do it and what can we learn from them. So. In. This next slide the. You will see the amazing efficiency. Durability adaptability and, self-healing, capability. For which the. Biological, systems, are endowed and these are some of the main inspirations of the material scientists, structure functionality, principles, and if, we look back in time the. Living beings had a very very long time to perfect themselves, in order to survive the age. Of the earth is about 4.5. Billion, years, and earliest, undisputed, evidence of, life of Earth dates, from at least 3.5. Billion years ago although, there is also evidence that life began much earlier, the. Global changes with processes, such as plate tectonics and solar variability have. Occurred over thousands. To millions of, years, on. A much smaller scale over decades, to centuries the. Human activities, have become an important, driver of the physical climate system, and the biochemical, cycles. To. Just give you a feel of how, long it took the living organisms, to evolve to, what they are now insects. Such as ants have, been around since one hundred and forty million years ago, well, the squid have. Been on this planet since about 100, million s ago our. Human lineage started, only about two million million. Years ago and about, two hundred thousand years ago our species, the homo sapiens, emerged, so. You might want to consider this the next time you step on an ant or have. Your calamari for, dinner. If. Aliens, ever visited, our planet and they decided to communicate, with humans one of their first questions, would probably be how, many distinct, life-forms does you planet have you.
Would Be surprised with a certainty, and now answer, which illustrates, our limited progress with this research topic, in. More than 250. Years since the swedish biologist, Carl Linnaeus began. The science of taxonomy. 1.2. Million species, have been identified and, classified it. Is estimated that it will take us another 480. Years, to complete the job, however. The linear system forms a pyramid like hierarchy, which is inverted, image of the taxonomic rank, shown here the, lower the category, the more entities it contains, there, are more species the general, more, general than families, more, families, than orders, and so on right up to the top levels the kingdom and domain. Recently. A new method was proposed, that allows the total number of species to be predicted, based, on the consistent, scaling pattern among the different levels of taxonomy classification. System. Order, genus, species and, so on, according. To the latest biodiversity. Estimate, based on this new method of prediction, there are eight point, seven million, give. Or take 1.3. Million UK eukaryotic. Species on our planet this. Means that the staggering 86, percent of land species and nearly, 8 91 percent of marine species remain, undiscovered. With. These numbers at hand we cannot even begin to answer questions, such as how, much diversity we can lose while, still maintaining the, ecosystem, services that humanity, depends on. So. Why, are the materials, so important, because, about, everything, you see around you is made of materials, from. The concrete walls to the intricate, parts of your smartphones, from, the smallest grain of sand to most complex systems like the living organisms, and we, want these materials, to be lighter thinner. Smarter. Better, we, care about how they look and feel how long they last and how much we need to pay to use them with. Great enthusiasm and, curiosity, material, scientists, and engineers working. In the biomimetic, materials research. Field ask why, natural, selection, may have favored one species over, another or one, design over another from. The labs of Harvard here, in MIT to, the deserts of rainforests, they seek to answer to. Why animals and plants have adapted and, involved, to disperse and traverse their environments, taking, advantage of physical, laws and environmental. Conditions, which, result that are both startling, and engineers. Our. Desire, desire, - an ability to imitate nature has also continuously, evolved, and as technology improves more, difficult challenges, are yet to come. The. Humanity, change forever, during the first Industrial, Revolution which. Began in Britain in the late 18th, century with, the design of an engine in which, burning, coal produced, steam which drove a piston, the. Second Industrial Revolution came in the early 20th, century when Henry Ford mastered. The moving assembly line and ushered. In the age of mass production it, witnessed, the expansion, of electricity petroleum. And steel the first, two industrial revolutions, made people richer and more, urban now. A third revolution is underway manufacturing. Is going digital and a, number of remarkable technologies, are converging, clever, software more, dexterous robots, new processes. A range, of web-based services, and particularly, important, for all these developments, noble, and better materials. Living. In the area of emergent, hyper-connectivity. We're on the cusp of the fourth Industrial, Revolution or, industry. 4-0, it. Is quite different than the three industrial revolutions that preceded, it because it is supposed to challenge even our ideas, about what it means to be human the. Fourth Industrial, Revolution describes. Exponential. Changes, to the way we live work and, relate, to one another due, to the adoption of cyber-physical systems. The, Internet of Things and the internet of systems.
Implementation. Of smart technologies, in our factories, at workplaces, connecting. Machines that will interact with each other visualize, the entire production chain and make, decisions autonomously. This. Revolution, will impact all disciplines. Industries. And economies, and again, it requires new better materials. In. Parallel with these developments there have been efforts to develop a global understanding of. The functioning, of the earth as a system the. Effort necessitated. Linking, knowledge and unifying methodologies. And conceptual. Frameworks, from, both the physical and biological research. Domains, and will, inevitably, result, in a highly integrated Science, and Technology, real, one. Of the motivations. For this development is the growing impact of humans, on the earth system, and more, importantly, the necessity, to provide solutions, while also recognizing the, impact of the relevant social drivers, and their consequences, for, the changes, that are occurred. Materials. Are derived from natural, resources and, material sufficiency has become an important. As important, as energy, efficiency, with efforts towards, a circular. Materialist, economy, where the materials, are reused, and to. Draw down from the national resources base. One. Of the critical components in that respect the transferring, an idea to application, is that of the design. The. Design is the process of translating, an idea into, detailed information, from which a product can be manufactured, the, starting, point in the design is a market, need and the, end point is the full specification. Of a solution that fills the needs, well. Many aspects, of the natural principles. Are beyond our understanding a, significant. Progress has been made in elucidating the, underlying, principles, in, a highly interdisciplinary exercise. Material, science, scientists, and engineers work. Together to, reverse-engineer, these, principles. Making. Biomimetic, materials and. Systems requires not only understanding. Of the basic principles but. Also modeling, graphic, simulation. Fabrication. Of the materials and systems and ultimately, physical. Implementation. Of the resulting, technology. But. Let's go back in time perhaps, the most famous story related, to the biomimetics, is that of the Swiss inventor George, de Mestral, in, 1941. The Mistral was on a hunting, trip and noticed that both his pants and his Irish pointers, here were, covered in the burst from a burdock plant, being. Curious from a very early age the, Mistral decided, to study the birds under microscope. More, out of curiosity than, because of a business opportunity. What. The Mistral saw were, thousands, of tiny hooks that eventually, efficiently. Bound themselves, to nearly any fabric, being. Inspired by science, they must realize. That if he could create a synthetic, form of this fabric it would, allow for a new way to fathom things a middle ground between buttons, zippers, and simply, sewing stuff together, his. Idea was to take the hooks and had seen, in the thicket, seen in the burrs and combine, them with simple loops of fabric, the tiny hooks would catch in the loops and things would just come together in. 1958. He was granted a patent, for his invention, for what would later become known as, velcro. The. Principles, of operation, of all biometric, materials, rely on capturing, the essence of biogenic, systems in, an attempt to emulate their functionality, by intentional, modulation, of their structure, and composition. The. Hierarchical, and mechanistic, trades that enable responses, to environmental stimuli. Are, central, to the advancement, of the biometric science, as they, inspire the design of durable, artificial, architectures. Some. Of the principles, can be harnessed to make miniature devices, that can fly like a dragonfly, adhere. To walls like a gecko adapting. Texture, pattern, and shape of the surrounding, like octopus, process. Complex, three-dimensional images. In real time recycle. Power of operation, and locomotion. Self-replicate. Or self repair grow. Using surrounding. Resources, or general. Generate, and store energy. Plans. For instance have prevailed and adapted, to different climates by, continually, perfecting, energy, conserving mechanisms, for dispersal, that utilize spatial. Temporal gradients. In temperature light. Pressure and humidity. Some. Futuristic, applications. Can also be in research such, as those that mimic the motility of a tumbleweed. Sophisticated. Through Baltic tumbleweed, like devices, could use the wind to operate on their own for years, traversing. Thousands, of miles of desert escape using. Only the way to send information on, the desert conditions, since. Mars has, its own wind which you can hear on this slide. Making. A rover, that has the structure of a tumbleweed, is an attractive, idea to design a vehicle which can travel great distances with.
A Minimal power as. A second, example this tumbleweed, inspired, prototypical. Minded to nature or the last picture, here it's composed almost entirely, of bamboo, and biodegradable plastics. Which was Kerensky with a skeletal, structure of spiky, plungers that resembles, a giant spherical. Tumbleweed, from another planet. Through. Evolution over millions of, years nature. Introduced, power efficient. Solutions, that, use air of or air currents. Mimicking. These solutions could improve our lives and the tools we use, trees. Disperse, their seeds by, using aerodynamics. Principles, to passively, travel, with aid of wind and these, principles, have been used to develop in, devices, from boomerang to gliders, to helicopter, blades to, aircrafts, and drones. Maples. Like many long. Dispersal. Tree seeds rely. On wind, upward, currents, and gust to spread their seeds over long distances, that can reach several kilometers, the. Wings seed of a maple called, Samara. Autogyros. As it falls, the, spiral motion is insensitive, to the initial conditions, and is, tabled against, wind, disturbances. So. Last spring I actually collected, some of these seeds. Here in front of Radcliffe and I would like to show you how this happens. So. These. Are the seeds, and if we throw, them they. Start to rotate, for. A reason. The. Interesting point here is regardless, how do you throw them in the air they've. Always stabilized, at their motion, and go. Into perfectly, steady, our descent. So. If you throw. Them. So. This. Is maple. Seeds are able to rotate, because. Of the, air, structure, because their center of gravity which, is determined, by the position of the heavy nut is, located, at the base of the wing shaped seed it has been observed that despite. Their small size and slow, velocities, these, seeds are able, to generate with lift being, able to remain in the air for longer times than other non rotating sees, a main, puzzle here has, been to understand, exactly how. The seed, settles, into their study descent. This. Stable, or the rotation of maple seeds of, or other similar, rotary, seeds depends. On the interplay, between their, three-dimensional inertial. And aerodynamic. Properties which, result, in unexpected. High lift forces this. They're small size and slow velocity. The. Generation, of so-called stable, leading-edge, vortex, similar to that observed in hovering, insects, bats and some, birds has, been shown to be responsible, for such high lift force. Robotic. Models seats that have been recently used to accurately predict, the presence of a, strong tornado like vortex, on top of the maple seed wings that, elevates, the lift and, increases.
The Deer dispersal, distance, from the tree. So, these the. Less these, lessons learned from the maples and other similar, seeds have been already used in s technology in, the design of unmanned, aerial. Vehicles, quadcopter. S and drones the. Maple seeds for example, were the inspiration for a new kind of flying machine that could be useful for military information, gathering Lockheed. Martin's intelligent. Robotics, laboratories developed, an unmanned, craft to replicate, the motion the, device named samurai has, only two moving parts in a camera it can be controlled by a remote control, or by an app on a phone. Planet. Earth has, been called the blue planet due to the abundant, water on its surface water. Is the most abundant resource in the natural environment yet, about 97%, of, the total water on earth is sea water the. Fresh water that is directly available to humans makes up only between, 0.4. And 2%, and comes, mainly from frozen, glaciers, and polar as ice caps a liquid. Groundwater, or aerial, humidity. In. A recent global risks, report water scarcity, has been ranked as one, of the highest environmental. And societal, risks, it. Is estimated that two-thirds, of, the world population will experience water stress by 2025. Approximately. 1 billion people live without access, to clean water resources. In, rural areas, of, African, Asian and Latin American, countries turning. The issue of water shortage, and scarcity into a major global concern. Using. An example of climate models and socio-economic scenarios. The, World Resources Institute predicts. That 33, countries will. Face extremely. High water stress by 2040. The businesses, farms and communities in Chile Estonia, Namibia, and Botswana could. Face especially, significant. Increase in water stress, by 2040. And these, countries will become more vulnerable to water scarcity than, they are today. 14. Out of 33 most water stressed countries in 2040. Are in the Middle East the, region already already. The least water secure in the world draws, heavily upon groundwater, and the salinated sea water and faces. Exceptional, watch related challenges for the foreseeable. Future. With. Regional violence, and political turmoil commanding, global attention the, water issue may seem a tangential, problem, however, looking into the future and according to the US National Intelligence, Council, the, water scarcity, will put key North African and Middle Eastern countries, at greater, risk of instability and state failure and will, distract. Them from foreign, policy engagements, with with the US. I. Live, in the Emirates and although this country is only about 45 years old the, main cities here are an, urban, jungle very, smooth to other metropolises. Like, New York City or Shanghai. So. If you drive only about ten kilometers from, here, we, will encounter very. Different environment, the Arabian desert and. There. Is no other place on earth where the contrast between the urban and the natural is so stark it is the fourth largest desert, in the world and the, largest in Asia the. Climate here is hot and dry with only about 100. Millimetre rainfall, per year miles. And miles of nothing but sand and wind yet. The desert is not a deserted, place in. Many regions, fokin do you represent regularly. Occurring phenomena, and him a substantial. Impact on the hydrology, and ecology, of the local vegetation over, several. Billion years of evolution, the nature has helped desert organisms, evolve. And survive, in, an extremely hostile, and arid environment, by harmonizing, the structure, and function and by making use of minimal.
Resources To attain maximum performance. Can. We learn something. From these amazing creatures. Meet the steno, cara beetle I think, Anna would love this part, it. Thrives in the Namib a coastal, desert in southern Africa, one of the most arid habitats on earth with, less than 13, millimeter. Rainfall, per year the. Steno cara beetle is able to harvest water on his bumpy back by, a combination of, hydrophilic, or vegetable, areas, on a hydrophobic. Or non wettable background. So. What happens is early in the morning when the dew in which fox settles over the dunes the beetle, climbs the dune peaks and positions, his body in a way that facilitates new, formation, the. Water condenses, on the wettable regions, and once, droplets, reach critical size, they slide down to non wettable regions, and the beetle slurps up the water dust formed. Inspired. By nature there are now extensive, efforts being made to utilize, this as a design. Principle and it has been already successfully. Replicated, for rock interception. To provide, clean water to, human settlements, in arid regions, these. Technologies, rely upon fog, water drop at the position, on two nylon mesh or Teflon fibers, these. Materials, allow condensation. Of droplets, on their surfaces, but, resist complete, wetting, schemes. Of this kind have been successfully, implemented in desolate, desert, areas, in countries, including South Africa, Namibia and, Atacama. Desert in, other northern, Chile. Several. Lizard species and, tortoises, that live in arid areas use similar principles, to harvest moisture from, humidity foggy or rain bodies. Of lizards such as the Australian thorny, devil Arabian. Thought had a gamma in the Texas horned lizard, have independently. Developed, body surfaces, that are covered, with honeycomb-like, structures. That, render the surface super hydrophobic, super, battable, super hydrophilic, asari, and increase. The condensation, of air humidity by about 100 percent the. Water spreads and is soaked into the capillary, system in between scales, which, transports, the water to the mouth where it is it isn't ingested.
The, Combination, of super wettability mite ornamentation. And the semi tubular capillaries. Allows. For passive, or directed, water transport, for their survival. Do. Not mess with these guys especially the last one on the other or the right. Indigenous. Plants, found in arid and semi-arid locations. Readily, cope with in insufficient, access to fresh water folk. Episodes, occur frequently in many of these regions and help, to augment the water supplies, for native botanic species, through the UN, for collection, as well as water vapour absorption. In. Addition to the adaptive, characteristics. That minimize, the water loss some, species appear, to use fork as an additional, water supply by using spines, that fulfill, multiple functions, the. Bunny ear cactus, are shown here he has an efficient for collection, system, composed, of well distributed, clusters, of conical, spines each. Spine, has, three integrated, parts that have different surface structures, and different, roles in the for collection, process. The. Full collection ability, of these and some other cacti, is believed to be driven by the gradients, in free surface, energy, and the so called laplace pressure. The. Surface wetting properties are, a combination of surface chemistry, and surface structures, their, underlying, benefits, are manifold, and range from prevention of settling of pathogens, to ensuring, floating, ability necrotic plants, to facilitating, the caching of prey by carnivorous, plants, in. 1997. Two German scientists, published the paper on the. Purity of sacred, Lotus and described. What later became note unknown is the Lotus effect. If. You take a close look at the surface of a lotus leaf you'll, discover a double layer of textures, waxy. Microscopic. Bumps are covered in - kale sized hairs, which, strap a thin film of layer when. The rain droplets, touch the lotus leaves they, remain spherical, which allows the droplets to bounce around until, they fall off the leaf which stays dry and clean this. Self-healing, effect can be also found in other species. Plant. Species birds, and even insects, this. Phenomenon, has aroused great interest. For its potential, for applications. In self-cleaning, materials, in, a number of different fields a different. Knowledge on how these services attain, the property, which is now referred to as super, hydrophobic. Is, key to reproducing this natural effect in glasses, for Windows clothes, and other materials, a particularly. Important, application, of this effect is in preparation, of self-cleaning superhydrophobic coatings. For solar cells which, could solve a major problem with decreased efficiency, of solar cells over time especially, in. Arid regions where which, are also endowed with highest insulation. You. Will be surprised to know that there are plants that out there that, do not even require a soil to survive perhaps you're familiar with the so called air plants, such as the tillandsia. Which, are biologically. Referred to as arrow fights, these. Peculiar, plants, make good houseplants, due to their minimal water and soil requirements, they, obtain moisture, and nutrients, from air from the air and rain they. Usually grow on other plants, but are not parasitic, on them and some can even live, on mobile sand dunes so. I did, bring some of these plants for you and you, will notice something. That is not. Characteristic for other plants which is the shape. Of the leaves, so. They have very narrow leaves shaped. Like a. Trap. And this. Serves, for collection, of of water. So. We. Can we can possibly learn something, from that and make similar system, that can be efficient water collectors, especially based. On the shape of the Leafs and the surface of that of these, leaves going. To the next slide Nature. Has devised mechanism, for active locomotion, of plants, typically, observed with rapid movements, for, prey, and defense or with very slow movements during the growth one. Of the frontiers, of the contemporary, material, science, research is, the design of a new advanced, activating materials, which, mimic, the motility and are capable of fast reversible. And controllable, mechanical, motion in whisper, in respond to external stimuli, such as heat light magnetic, field or electric, field. The. Research efforts, in this field are driven by the potentials, for utility, of such motion, to, perform, mechanical work, which could have far-reaching my, technological. Is mechanically. Active elements, for example in the future micro, nano robotics, which will be soft organic, and human like the.
Remarkable, Ability of geckos, to climb vertical walls, and ceilings has, inspired philosophers. Scientists, artists, and laymen, for over two millennia. Aristotle. Noted the ability, of geckos to run up and down in a tree of, at odometry, in any way even with their head downwards. Geckos. Used millions of adhesive, hairs on their toes to climb vertical surfaces at, speeds. Of over one meter per second which is about two miles per hour. Climbing. Presents, a significant. Challenge for an his even requiring both strong and firm attachment, and easy, and rapid removal the. Attempts to mimic the Gecko toe pad is one of the endeavors of the fascinating, field of evolutional. Nanotechnology. Which, focuses, on developing, new functional, and smart materials, by utilizing, design, principles, that have been developed. Throughout the evolution in nature. The. Impressive adhesive, properties of the geckos topaz have been attributed to the, nature cellar design of hierarchical, biological. Structures, realized. With fine hairs on the geckos feet which, results, in an unmatched, demonstration. Of the power of adhesion. Gecko. Toes are now well studied and their sticky properties, have inspired some incredible. Technologies, such as stitch, free ways to seal wounds and sticky. Handheld, paddles that may help soldiers scale, walls someday, the. Fascination, with the mechanism, of adhesion has, resulted in several attempts, to develop and test new synthetic dry, adhesive materials. Inspired. By the Gecko toe pads, however. The ultimate goal of creating a perfect mimic that, would reach the performance, of natural gas of food here as has not been accomplished. Yet which, has even brought dispute, over the originally proposed mechanisms, of adhesion. To. Disseminate, some. Plants, have become, capable of active, migration, by, reversibly, changing, their shape and, have developed systems, to disperse, by creeping crawling.
Ratcheting. Buckling, and slithering, other. Plants, have developed mechanisms, for, passive motility where there are seeds can, buckle, or explodes or to disperse or, burrow themselves, in the soil in response. To periodic changes. In humidity or temperature. Hydro. Responsive, plans for instance utilise fluctuations. In area you midde tea to, enhance seedling survival, and represent. An alternative approach, to environmental, energy transduction because. The, hydro motility does not require light or heat and is driven by slow diffusion, control processes, that, elicit, reactions on longer, timescales a. Multitude. Approach, of approaches, to realization of biomimetic activating, magma moving devices has, been advanced, through, the design of single molecules, polymers, and, composites. Where. External. Stimulation by heat light humidity, or magnetic or electric fields in use, uses. Structural, changes, to drive macroscopic motility. When. In arid conditions some. Grass owns commonly. Undergo, torsional, motion for burial, for example the owns of grasses such as the middle needle and thread grass are. Effective. Drillers, that are capable of, self cultivation by propelling, themselves into. The soil. Resurrection. Plants such as the spike Moss are famous, for the ability to survive, extreme. Dehydration and, desiccation, during. The dry season, the branches curl inwards, forming, a dead looking ball when, dehydrated. The plant can be uprooted. And become tumbleweed, that blows along the ground with the wind when. Moist and the plant is coming out of the dormant state induced by the severe, dehydration and. Opens up in. My lab we have used the some of these principles to prepare materials, which are able to drill and burrow themselves into. The surface, in response, to periodic changes in humidity in. The example, shown here we, have prepared a material, that mimics this behavior, and can, open and close reversibly. When it is exposed to water it, can also feel the presence of a human and can move autonomously by, using only the gradient in aerial humidity. Such. Hygroscopic materials. Have the advantage of long lasting irreversible. Actuation, in absence, of light and without thermal, or photochemical, degradation. Practical applications range from power generators, and smart textiles, to artificial muscles, and sensors. Some. Of the most fascinating phenomena. That have inspired biometric. Research are related to the ability of living systems, to use or to generate light. Light. Is a thermal but, aterial. Light. Does not require a contact, and therefore, provides, means for a remote control, - biological, or artificial systems. Light. Interacting, biological, structures, reflect, the uniqueness of the nature's optical, design but, they also suggest, broad innovation, in nature's use of materials, and its manipulation, of light, and.
If. We can just have the lights dim please. This. Is our planet, and if you look very closely you might see a strange blue glow off the coast of Florida, when, the Florida comes into the picture. This. Bright blue glow in the ocean is produced by a subgroup, of algae called, dinoflagellates. Which are the main eukaryotic. Organisms, that are capable of generating cold. Light so, that would be somewhere here you can, see this blow. When. Their population are, dense. Disturbance. Of the water during night causes, bright blue bioluminescent. Displays that, have been reported, since at least 500. BC and are known to occur globally. Bioluminescence. Are the, phenomenon, of biological, generation. Of visible cold light by, the excitation, of chemically, produced excited, States he, has been documented as early as Aristotle's, the anima about 350. BC it has, inspired chemists, writers, artists, and laymen, for thousands, of years, it. Is displayed by a number of organisms, including certain, species of bacteria insects. Jellyfish, mushrooms. Worms and squid there. Are about 70, biological, families, of lower organisms spanning. Over 250. General, which, are known to display bioluminescence. Only. The family of beetles known as fireflies, for example contains five genera, and about 2,000, species. So. In. The, bioluminescence. World the, core physical, process, of this natural phenomena. Energy, transduction by, which living organisms, use enzymes to, convert the chemical bond energy of ground state reactants, for, electronic excitation, of the reaction products, the. Chem excited products subsequently, emit light in the visible region of the spectrum which is used to communicate signals. The. Bioluminescence. Is used for communication prey. Of defense, or defense so. In the bioluminescence. There are these creatures. Watch such. As the civil slugs, which are the good ones and there, are the bad ones such. As these dragon fish and of course they are the ugly ones, and. This would be the ugly ones this. Type were the type locality of this warm called the block Rd alonga is a small town in Georgia in the u.s. it's body fluids and the sticky slime that the worms decreased when stimulated emit, a bluish, glow the. Nature of the emitting chemical, species however remains uncertain.
Also. There are the scary ones as well so, dish this fish known as photo blarin, uses, luminescent, bacteria under, its eyes you. Don't want to meet this guy in a dark alley, but. It is scary because it's very really tiny and harmless. So. The light of the bioluminescence, has been utilized. And, provided, an irreplaceable, analytical. Methods for precision, with precision on a pico mall range this is 10 to the minus 12 and evolved. Into one of the first non-invasive methods for visualization of cell and tissue organization. The. By analytical techniques based on bioluminescence. Have become some of the most versatile, and powerful analytical. Tools developed. In the 20th century they. Are nowadays extensively. Used for in vivo imaging for. Monitoring of cell proliferation protein. Folding, and secretion, environmental. Research food, quality control, and protein, and genetic engineering the. Bio analytical, techniques based on bioluminescence. Are sensitive, reliable. Quantitative. Rapid, non-invasive. And generally come with a high signal-to-noise, ratio. However. Some of the most recent biotic applications, in material, science, are focused. On the Firefly landers which, help to very efficiently uncouple. The light from the body and to deliver strong, optical, signals in sexual communication. The. High transmission, nanostructures. Of the Firefly Lantern cuticle, have become biological. Inspiration for highly efficient LED illumination. Such. Biologically. Inspired LED. Lenses, substantially. Increase the light transmission, over visible, range compared, to conventional, and reflection. Coatings. One. Of the most remarkable consequences. Of, the orders and patterns, that are generated spontaneously is, the so-called structural, color the. Description, of these optical, effects is as old as the Robert Cook's famous, book micrographia published. In the 17th. Century where. He presents microscopic. Images, of brilliant, feathers, of peacocks and ducks and reports. That the colors of their feathers, are destroyed, by, a drop of water, when. A matter is illuminated, with white light we see color only the reflected light is of particular wavelength. That is detectable, by our eyes, there. Are two ways to eliminate, the remaining wavelengths. By absorption, as is the case with colored, material such as pigments, dyes and metals where, the color is due to the exchange of energy between the light and electrons, in. The second case the light is reflected, scattered, and deflected. And it doesn't reach the eyes because, of the physical phenomena, that happen, on the specific, surface structures. In. Nature these colors are enhanced, by thin film and multi-layer. Interference. Diffraction. Gratings. Light a light scattering, or photonic, crystals, so, if you look at these pictures you see the different, structures, in the blue region here, then in the green region and there is a further degree. Of complexity, because if you zoom in these, structures. You will see even finer a tinier. And finer structures. That actually all contribute, to light without any pigmentation. Some. Insects, and butterflies species. Use similar complex photonic, bandgap structures, that prevent propagation. Of a band of wavelengths through, them and thus, cause very strong colors reflections, in, butterflies. Such as the Blue Morpho butterfly the, visibility. Of up to 1/2 mile is attributed, to photonic, structures, that are formed by discrete, multiple, layers of cuticle. And air. The, butterflies use light, interacting, structures, on their wing scales to, produce color the. Cuticle on their scales is composed of transparent. Chitin, and air layer structures, with, size from, the nano scale to the micro scale. These. Multi scale structures, cause light that hits the surface of the wing to diffract, and interfere, cross. Reefs that protrude from the sides of the ridges on the wing scale diffracting. Incoming light waves causing, the waves to spread as they travel through spaces, between, the structures, the. Varying heights of the wing scale ridges, 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, thermal, regulations, am signaling. So. Before, I go on to the last part of my talk I would just like to briefly introduce, two. Last examples that, come from faculty, who are now here at Harvard where, there is a very active research in this biomimetic, field, the.
First Is a, sessile deep water sponge, known as the Venus flower basket. It's called Venus flower basket because it has a couple of streams that remain, a trapped there forever forever for, life, so, this is a symbiotic organism. This. Impressive, structure was studied by Jonah Eisenberg, here at Harvard and although. It is essentially, made of the fine fibers, of glass with diameter, close to the head of a human hair it gets withstand, enormous, pressure, at the seafloor due, to a specific, hierarchical, structure, which embodies, reinforcements. At multiple, levels. The. Second example comes from the laboratory of Lakshminarayana, Mahadevan, it. Explains, how tendrils, of cucumbers, and some other plants work once. It is attached to a solid surface the tendrils, shortens, into a helix pulling the plant but. Rather than twisting, in only one direction which is impossible without twisting, the plant on the other hand the, two halves of the coil section, curl up in opposite directions, separated. By an uncoiled, stretch so, there is no net twist. In. Addition to being a significant, component, of a bio-inspired architectural. Design a portion, of the biomimetic. Research is proprietary to, specialized, national defense labs that. Develops tell technologies, and is not available to public the stealth. Or low-observable, technology, covers a combination. Of techniques that range from aircraft shaped, to special, low observable coatings, that are used to make personnel or military, objects or vehicles, less visible, or invisible to. Radar infrared. Infrared, sonar, and other direct detection methods, the. Very early stealth technologies, involved, the concept of camouflage, producing. The visual signature, by, making appearance, of an object blend into the visual background. Increase. Capability of, the detection interception. Technologies, required, advanced, materials, that, either deflect, or absorb, electromagnetic waves. From tracking devices, for. Example central. To the design of the f-35, Joint Strike Fighter design. Is the, application of composite, materials, such as composites. Of fiber mats and polymers, to, reduce observability. On maintenance. Costs, while. Avoiding applications, of aesthetic, stealth coatings. Future. Increases in human welfare will be driven by the increased, understanding and, mastery of the natural world and the materialist. We scientists, are posed to expand the, frontiers of human knowledge by, exploring these secrets, but. The globalization, has, a dark side too we. Are living in an urban century. And, demographic. Forecasts. Indicate that, world, population will reach 9 billion by 2050. Which, is an increase of 2 billion than at present. Being. A phenomenon, of physical, and cultural restructuring. The globalization, will have complicated, and far-reaching social I, stated. Economic, and physical and political, effects. Environmental. Challenges, facing the planet are complex, and their impact on the natural world and on human society can, be catastrophic, climate. Change loss, of natural resources declining, biodiversity. Therefore, station and the certification. Changes. In the carbon nitrogen and phosphorus cycles, sea-level. Change and pollution each post enormous, problems, both regionally, and globally and, indicate. A dystopian. Future. So. On this slide you can see some of the species that are already extinct, or close to extinctions. These, challengers. Are intricately, interwoven, with, issues, of human health population. Migration. Water, food, and energy security and, it inevitably. The potential, for conflict, they. Require a broad interdisciplinary, approach. To understand, them and to provide solutions, many. Of these challenges, already have had or will have direct impact locally, our, planet. Is now in the midst of the sixth wave of mass extinction, of plants. And animals in, the past half billion years, we're. Experiencing. A divorce state of species, die offs since the loss of dinosaurs, 65 million, years ago it, is estimated that we are losing species. 1,000. To 10,000, times the background, rate which is one to five species per year, these. Slides that I showed, showed. Only a few of these species that are close to extinction or extinct, and this. Is only a small fraction of the species that we are aware of there are many more species both, small and big that, will loss forever without us even knowing that they ever existed.
So. There are several questions that I will post at the end of my talk can we reverse this process, can. We prevent slow down destroying, or remedy nature while continuing, to increasingly, explore, its resources, and, does. The humanity, really need a backup planet. Thank. You.
2019-04-14 08:53
