BOOK OF INSPIRATION
POLITECNICO DI MILANO
A. Y. 2016/ 2017
School of architecture and society
Supervisor: Prof. Arch. Simone Giostra
Master of architecture
Student: Nadezhda Safronova 832804
CONTENTS

Introduction
3
Photonic system
4
Structural skeleton
8
Water collection
14
Load distribution
20
Community sharing
30
Temperature regulation
36
Structure and form
38
Water purification
50
Circulation
52
Replaceability
56
Connection
60
Ventilation
62
Moisture protection
64
Bibliography
66
Introduction It seems that human has build already all possible variety of forms, though nature is still a grand source of inspiration. Besides ethetical beauty, all these structures are showing maximum structural efficiency and minimal material expenditures. These are sketches of intersting engineering solutions that could be found in nature accompanying my thesis project about biomimetics.

PHOTONIC SYSTEM
EDELWEISS
Leontopodium nivale/ alpinium

Scheme of multidirectional hair growth and cross- section of one hair, showing that besides reflectivity hairs have a rough surface that also helps to avoid heating.
Reflective hair Edelweiss is one of the examples of a photonic structure found in a plant. Wooly layer covering the plants absorbs near- ultraviolet radiation before it reaches the cellular tissue. Another function of white hair is limiting water evaporation because the plant distributes mostly over very dry and windy regions. The thickness and density of this hair layer is highly variable. The filaments are clearly seen to be transparent with a refractive index not very different from that of water (circa 1.4). The filament has a diameter of about ten micrometers.

PHOTONIC SYSTEM
FENESTRARIA
Fenestraria rhopalophylla

Mechanism of Fenestraria to avoid direct sunlight letting it go through plant's transparent skin.
Heat barrier This plant can be seen in African desert. The amount of plant body outside the ground varies depending on light conditions. For example, European climate lets it grow rather high while in Africa only an upper part is visible. The protection of fenestraria is a very curious solution. On the ends of leaves there are no chlorophyll, they are transparent. In this way sun rays enter this kind of "hothouse", don't burn the plant and give needed amount of light to the inside of leaf.

STRUCTURAL SKELETON
VICTORIA REGIA
Nymphaea victoria/ Victoria regina/ Euryale amazonica

Density of structure is always constant that gives great stiffness.Thickness of leaf supporting veins is proportional to mass of leaf part it supports, so in the centre structure is more massive.
Constant structure density
The leaves of Victoria Regia could be up to two meters in diameter. Though their thickness is not very small, they are capable of sustaining a grown- up man. That is thanks to their organization. Structure of leaf is very interesting from the structural point of view. Big "wires" come from the centre of the leaf and spread decreasing their diameter. In this way the gap between structural parts is always small and this kind of net supports the leaf very efficiently.

STRUCTURAL SKELETON
CHOLLA CACTUS
Cylindropintia fulgida
With time living cells die, turn woody and act like a foundation for new cells that are filled with water , therefore rigid and structurally stable.
Constant reuse Cholla is a cactus native to the southwestern United States and northern Mexico. It is a tall thin branching cactus plants known for having numerous spines. Chollas rarely reproduce from seeds, instead growing a genetically identical plant from a severed piece of steam that gets torn off the original plant. provides stabilization via hollow cylindrical struts joined as trusses.Thin walled cells filled with water provide rigidity since they act like small pressured containers. As the plant matures, the living and active epidermis cells can function for decades before turning woody. So the plant structure acts like a system of hollow cylindrical struts joined as trusses.

STRUCTURAL SKELETON
VENUS FLOWER BASKET
Euplectella aspergillum Owen
Increasing the amount of structural levels, construction becomes more efficient.
Hierarchical leveling helps to provide strength. Skeleton of sponge provides strength with lightweight material via its siliceous composition. In this species, the skeleton comprises an elaborate cylindrical lattice-like structure with at least six hierarchical levels spanning the length scale from nanometers to centimeters. The structure consist of a central filament surrounded by concentric silica nano particles and interlayers. Two intersecting grids define a locally quadrate, globally cylindrical skeletal lattice onto which other elements are deposited. The grids are supported by spicules that form vertical, horizontal and diagonally ordered struts.
Flower basket has five or more levels of hiererchy.

WATER COLLECTION
DISCHIDIA
Dischidia rafflesiana
t
Roots are growing inside of the sack- form leaf. They always stay humid, as due to the difference of the temperature inside and outside water is condensated on the inner surface .
Hot temperature helps water condensation.
That plant has two types of leaves: the flat ones and sack- formed that are of great interest. They store a complicated system, resolving the problems of storage, collection and usage of water. Due to the dramatic changes of temperature, on the inner surface of leaves the water is condensated, that is used directly by the roots of the plant that are growing inside this leaves. Moreover, the level of humidity is never too low and the amount of evaporated water is minimal.
Inner structure of leaf.

WATER COLLECTION
NAMIBIAN FOG- BASKING BEETLE. Stenocara gracilipes
water waxy surface
Shell surface is covered with hydrophilic bumps and hydrophobic wax finish that makes water collection effecient.
Water from air That beetle climb on the dune top during the night. As the surface of its body is black, it radiates heat in surroundings and becomes slightly cooler. When the breeze is blowing, water droplets appear on its back. After it has collected enough of water, it rises his shell in a way that water slides to its mouth. Moreover for further effectiveness it has small bumps on his back surrounded by waxy finish that is hydrophobic.

WATER COLLECTION
ELEPHANT FOOT PLANT
Beaucarnea recurvata
Water storage Elephant Foot Plants (Discorea elephantipes) have swollen bases for water storage and can store water from six months to a year. It does this by retaining water within its root structure and base of the stem. The root structure does this by expanding and contracting according to the amount of water stored through the transfer of water from the soil. In general, the older the plant, the larger the base will become.

LOAD DISTRIBUTION
ABALONE SHELL Haliotidae
Alternating layers- hard inorganic and soft organic make the structure more resilient, preventing cracking.
Alternation for breaking resilence. Abalone shell structure is represented by an elastic organic protein material between rigid inorganic calcium carbonate structure. Thanks to that alternation cracks do not go further than protein layer. While the inorganic layer provides the hardness, the organic provides the toughness to the shell. The organic constitutes less than 5% by volume of the composites. This results in an "ideal" impact resistant material. Hence, shells are incredibly resilient to breaking, despite their thinness.

LOAD DISTRIBUTION
METACARPAL BONE OF A HORSE Equus caballa
In a metacarpal bones of a horse, voids for blood vessels are made in a way that doesn't decrease structural strength.
Voids form optimization
The presence of a hole in a structural element offers the potential for it to act as a site of stress concentration and initiation of cracks, but do not weaken the bone nor act as fracture initiation sites. The key features that minimize cracking are: their location in regions experiencing compression, elliptical shape, the softening of the material discontinuity by increased compliance of the tissue around opening, and a ring of increased stiffness distanced from it to absorb stresses shifted from the compliant foramen edge.
Watching the cut of horse forefoot bones it is visible a high amount of voids for blood vessels. They are organized in a way that would not decrease structural performance.

LOAD DISTRIBUTION
BIRD SKULL Aves
max load
min load Some areas more dense than others depending on the loads applied.
Light and stiff Bird bones are slightly different to other animal bones as they have changed over time to become lightweight so to allow the bird to fly. This is achieved through incorporating a large amount of hollow space within the bone itself, however to maintain strength, the bone layers lightweight structures with stronger, denser structures where needed. The thinner the bone, the more dense the bone structure. Its is also possible to see the layering of these structures.

LOAD DISTRIBUTION
DRAGONFLY Anisoptera
Dragonfly wing movement simulation Source: ZQ spring 2012
Flexibility is a key to structural stability.
The morphology of dragonfly wing is an optimal natural construction built by a complex patterning process, developed through evolution as a response to force flows and material organization. Variations of quadrangular and polygonal patterns follow multi- hierarchical organization logics enabling it to alter between rigid and and flexible configurations. The concentration of stresses and bending moments must have imposed strong selection pressure in the development of the nodus. The patterns of the wings follow the general tensile forces exhibit on the wing. The various shapes carry the responsibility of determining the amount of stiffness or flexibility in that area of the wing. Two main types of joints occur in the dragonfly wings, mobile and immobile. Some longitudinal veins are elastically joined with cross veins, whereas other longitudinal veins are firmly joined with cross veins. Scanning electron microscopy reveals a range of flexible cross-vein and main-vein junctions in the wing, which allows local deformations to occur. The occurrence of resilin, a rubber-like protein, in mobile joints enables the automatic twisting mechanism of the leading edge.
Dragonfly wing is a system of joints- mobile and immobile that allows to maintain structural strength staying flexible.

LOAD DISTRIBUTION
BAMBOO
Bambusoideae
structure more dence near borders
cross section is priorly oval Mechanisms of bamboo to prevent buckling.
transverse bulkheads
Stiffness and buckling resistance with minimum material. The stems of bamboo may resist buckling by including transverse bulkheads that prevent ovalization. Besides the bamboo is in its outer parts hard and in its inner parts weak, what causes a very stable construction. The tubes, normally circular in cross section, go oval prior to buckling, and that reduces the critical force. Preventing that ovalization may be one of the roles of the periodic transverse bulkheads so in, bamboo. The structure of bamboo consists of fibres that are more dense while approaching the outer core.
Non- homogeneous fibres diposition provides stiffness with material economy.

COMMUNITY
CLIFF SWALLOWS
Petrochelidon pyrrhonota
wind resistance
load resistance
Form is driven by the empty space left between already built nests
Form to fit Also of importance in the evolution of colonial nesting are the spatial restrictions which narrowly specialized behavioral characteristics impose on a species. The specialization, whether inherent or traditional, which restricts nesting gulls and alcids to small islands so limits the number of usable breeding sites that procreation of the species depends on maximum utilization of the available space. A similar situation applies in the Cliff Swallow. The special environmental requirements for nesting in this bird include importantly a protected overhanging cliff, or cliff substitute, a source of mud of suitable quality for nest building, and an open foraging area. Sites containing all these essential features in close proximity were decidedly rare in North America before European settlement, and if each adequate site because of extensive territorial requirements could support only one pair of swallows, the dispersion would have been dangerously sparse for procreation and survival of the species. Any behavioral mutations which served to reduce the size of the defended territory around the nest and thus permit colonialism would, under such conditions, have survival value and be perpetuated.

COMMUNITY
SESSILE BARNACLES Cirripedia
Density of deposition increases strength of the whole structure.
Bonding together for greater strength Space optimization is a concern for a number of creatures, particularly in situations where physical habitat is limited. In these situations, members of a population optimize space utilization depending on population size. The resulting pattern of space use reflects competitive and cooperative processes that are more complex than optimization patterns due to material or energy resource efficiency alone, as seen in many of our previous examples. The patterns of space utilization in colonial organisms are not as regular as those seen in the Fibonacci sequences, hexagons, or other examples presented herein, and therefore are not studied in the same contexts. Some trends, however, have been noted, particularly with regards to the relationship of individual mass to the population density primarily, as density increases in a space limited environment the average mass of the individual decreases. Interestingly, for a wide variety of species, including barnacles, this relationship is close to the exponential constant of 3/2.

COMMUNITY
TREE ROOTS Roots
Exchange between trees through root system helps surviving.
Sharing for surviving Trees are traditionally considered as distinct entities even though they can share a communal root system through root grafts, which are morphological unions between two or more roots. During periods of root graft formation, root grafting tended to reduce radial growth of jack pine trees, after which growth generally increased. The influence of root grafting on growth was more significant in natural stands, where root grafting was more frequent than in plantations...These results suggest that root grafting initially is an energetically costly process but that it is afterward nonprejudicial and maybe beneficial to tree growth. The use of a communal root system allows for a maximum use of resources by redistributing them among trees, leading to increased tree growth. A distinction is usually made between mechanical and hydrological effects of roots without much focus on the influence of architectural characteristics on these effects. Some commonly used architectural characteristics are the spatial distribution of root area ratio for slope stability analysis and root density or root length density for analysis of water erosion control. But many other architectural features, such as the branching pattern, root orientation and fractal characteristics, seem empirically and intuitively related to the effect of root systems on erosion phenomena. Many links between root system architectural characteristics and their soil fixing effects probably do exist and more links could be identified. However, most of these links remain very weak and empirical. The research which is needed to make these relationships explicit is still poorly developed and mainly focused on resistance against uprooting by wind loading. Moreover, although the mechanical and hydrological mechanisms of soil-root interaction are rather well described for simple processes such as sheet, rill or interrill erosion, this knowledge is almost nonexistent for complex processes such as gully erosion. This hampers understanding the importance of root system architecture for these processes.

STRUCTURAL STABILITY AND TEMPERATURE REGULATION
TERMITE'S MOUND
Isoptera's mound
outer wall central shaft air channels ridge stored wood fungus garden royal chamber brood chamber Deposition of functions in termite mound.
Advanteges of arched structure In order to create optimal temperature conditions mounds are created as a complicated and elaborated system. The secret is a combination of steady ground temperatures and wind ventilation. Termite mounds, having the form of oval in plan are planned north- south along the longer side. So vast area is absorbing warm lights, while when in the middle of the day only thin side is exposed to the direct sunlight. It is assumed that when it is getting too hot inside the mound, ventilation shafts can be opened so the warm air rises. The nests of termites gain structural support for chambers, ventilation shafts, and insulating cavities because arches are the main architectural element. The arches, supporting a network of other arches, provide most of the structural strength needed to support specialized chambers, ventilation shafts, and insulating cavities, and they supply convenient walkways as well. Recycling feces is a superb way to turn a problem into a solution. Network of arches provide structural strength to mound.

STRUCTURE AND FORM
POMELO
Citrus maxima
Air bubbles makes pomelo peel spongy thus resistant to deformation even if it falls from the big heights and it has a noticeable weight.
Air spaces inside structure prevent deformation. The pomelo fruit has excellent damping properties due to the hierarchical organization of its composite peel, called pericarp. The mesocarp with its airfilled intercellular spaces represents a compressible foam. Analyses of pomelo peel revealed a gradual transition in density between exocarp and mesocarp. Structurally, the dense exocarp can't be separated clearly from the spongy mesocarp. Due to this lack of an abrupt change in tissue composition,structural and mechanical properties the risk of delamination of the tissues is reduced.

STRUCTURE AND FORM
WEAVER BIRD NEST Ploceidae
Complexity of structure increases stability. Naturalists consider these birds' nests to be the most astonishing structures built by birds. This species uses plant fibers and tall plant stems to weave themselves extremely solid nests. First of all, a weaver bird collects the building materials. It will cut long strips from leaves or extract the midrib from a fresh green leaf. There is a reason for its choice of fresh leaves: The veins of dry leaves would be stiff and brittle, too difficult to bend, but fresh ones make the work much easier. The weaver bird begins by tying the leaf fibers around the twig of a tree. With its foot, it holds down one end of the strip against the twig while taking the other end in its beak. To prevent the fibers from falling away, it ties them together with knots. Slowly it forms a circular shape that will become the entrance to the nest. Then it uses its beak to weave the other fibers together. During the weaving process, it must calculate the required tension, because if it's too weak, the nest will collapse. Also it needs to be able to visualize the finished structure, since while building the walls, it must determine where the structure needs to be widened.

STRUCTURE AND FORM
WASP NEST
Vespula vulgaris
Bee "prints" layer by layer.
Natural 3d printing In nest construction, many social wasps use an oral secretion to cement together nest material, e.g. plant fibers, primarily composed of cellulose. Nests are waterresistant due to the saliva-cellulose matrix. The chitin-like saliva is primarily protein with high proline content. When mixed with the cellulose, it dries quickly and irreversibly to a water insoluble, water repellant surface. In general, wasps in rainy environments add more saliva to the mixture, because the saliva's mucoproteins provide adhesive and hydrophobic properties, like most other polistine wasps depends for its secretory production on proteinaceous materials.
The process of nest building

STRUCTURE AND FORM
SEA ANEMONE Actiniaria
Anemone changes its position to get more food.
Flexing for food collection In some cases, nature capitalizes on the way hollow tubes bend. A tall sea anemone, Metridium, has an area of its columnar body just beneath the crown of tentacles that is narrower than anywhere else. The material properties of the stalk don't vary, but when a gentle water current is present, the stalk bends at this point rather than at the bottom, and the tentacles are exposed broadside to the flow in the best position for feeding on suspended matter. It doesn't take much narrowing to concentrate the bending depends strongly on radius.

STRUCTURE AND FORM
GIANT GREEN ANEMONE
Anthopleura xanthogrammica
max
elastic modulus increase
max
min
distance from bending axis
min
Elasticity increasing in the more vulnarable zones.
Increasing elasticity with increasing height helps stress resistance. Anemones resist bending because of the high stress resistance of the tissues and the distance of those tissues from the axis of bending. Green Anemone has a flexural stiffness, that is the ability of a beam-like organism to resist bending. The higher the elastic modulus of the organism's tissues and the greater the distance of those tissues from the axis of bending, the less the organism will bend when loaded.
Cross section of anemone body.

STRUCTURE AND FORM
FAN PALM
Livistona chinensis
Wind aeration and equal sun light distribution
Accumulating sunlight, avoiding sunburns In nature the green leaves of plants are the equivalent to photovoltaic panels. They absorb solar light, converting its energy into electricity (electrochemical energy) for water splitting and the generation of chemical energy carriers. Excessive heating of leaves to temperatures above 40- 45 degrees C can seriously damage the chemical structure and the function of biomolecules and, therefore, such high temperatures should be avoided, for example, the potato leaf does not tolerate temperatures above 40 C. Nature has consequently developed a series of adaptations, which help leaves control the temperature. One is, of course, water evaporation, which, however, is restricted to areas with sufficient water supply. Another strategy is to keep the heat capacity low by means of building very light leaf structures so that the accumulated heat can easily be transferred to the atmospheric environment. It is also known that the leaf size decreases geographically with increasing solar energy input. Palm Licuala ramsayi from northeastern Australia leaf fan provides a large solar absorber area. However, the leaf is cut into segments, which are tilted in such a way that the air can pass freely through the fan transporting off heat. In addition, during a heavy storm, the fan follows the wind and the segments reorganize to a streamlined pattern from which they recover unharmed.

WATER PURIFICATION
EASTERN OYSTER
Crassostrea virginica
Sources of N atmospheric runoff fertilizer
N2 ng
i az
N2
algae
as
si m
ila
tio n
gr
organic nitrogen m re o ti za
i al er
in n
Sinks of N denitrification transport burial
NH4+
NO3
nitrification
den
itri
fica
tion
N2
Sediment Nitrogen Cycling in Oyster Reef Ecosystems: Nitrogen fuels algal growth in coastal systems. As the oysters eat the algae they delivery organic N to the sediments. This nitrogen undergoes a series of complex reactions and some of the nitrogen may be converted to N2 gas and be removed from the system.
Natural dentrification Coastal ecosystems rely upon oyster reefs to filter water, provide protection from storms, and build habitat for other species. There are two curious detail about that organism: a biomineralized adhesive that allows to construct such extensive reef systems and their way to clean water. Adhesive cement is an organic- inorganic hybrid and differs from the surrounding shells by displaying an alternate CaCO3 crystal form, a cross-linked organic matrix, and an elevated protein content. Oyster reef restoration is now a mainstream approach to control nutrient pollution as this coastal ecosystems have a natural means to remove nitrogen. Nitrogen pollution in these sensitive ecosystems can lead to algal blooms, eutrophication and dead zones. This mechanism is denitrification- the microbially mediated reduction of nitrate, a bioavailable form of nitrogen, to N2 gas, a form of nitrogen that most algae cannot use. When oysters feed they move nitrogen in algae from the water to the sediments through the production and accumulation of biodeposits. These biodeposits fuel sediment microbes and, when conditions are right, enhance denitrification. Converting the nitrogen in algae to N2 gas involves a series of reactions and pathways, where there can be leaks and some nitrogen may be recycled back to the water column before it is convert to N2 gas and removed. Denitrification is commonly used to remove nitrogen from sewage and municipal wastewater and oysters are an example of efficient cycle.

CIRCULATION
SLIME MOLD
Physarum polycephalum
slime mold network
actual Tokyo railway network
slime mold network
actual UK roadway map
Source: Andrew Adamatzky, & Jeff Jones (2009). Road planning with slime mould: If Physarum built motorways it would route M6/M74 through Newcastle International Journal of Bifurcation and Chaos
Mold finds the shortest way. The slime mold, Physarum polycephalum, is an extremely effective forager capable of creating extensive and highly efficient networks between food sources. This single-celled creature, classified as a protist, oozes its way across surfaces in search of bacteria, fungal spores, and other microbes to feed on. As it spreads and grows in search of food, it naturally organizes itself into a network of tube-like structures that quickly and efficiently connect its disparate food sources. Physarum maximizes its ability to find food by "remembering" and strengthening the portions of its cytoplasm that connect to active food sources. By rhythmically contracting and expanding its body, Physarum is able to move and grow its body in search of food. When it fails to find food or the food source dries up, Physarum retracts its cytoplasm, leaving behind a trail of slime essentially marking which pathways are useful and which are dead-ends. By trimming back connections and maintaining only active pathways, Physarum uses the least amount of resources and energy possible while still creating a resilient and fault-tolerant system. Links between food sources are made covering the shortest possible distances, but are connected in such a way that a disruption in one area does not impact the overall health or efficiency of the slime mold's network.

CIRCULATION
LUNGS
Pulmonarius
Thickness and length are decreasing proportionally.
Division for effeciency The vessels found in mammalian cardiovascular and respiratory systems are usually arranged in hierarchical structures and a distinctive feature of this arrangement is their multi-stage division or bifurcation. At each generation, the characteristic dimension of the vascular segments will generally become smaller, both in length and diameter. The branching structures found in mammalian cardiovascular and respiratory systems have evolved, through natural selection, to an optimum arrangement that minimizes the amount of biological work required to operate and maintain the system. The relationship between the diameter of the parent vessel and the optimum diameters of the daughter vessels was first derived by Murray (1926) using the principle of minimum work. This relationship is now known as Murray's law and states that the cube of the diameter of a parent vessel equals the sum of the cubes of the diameters of the daughter vessels.

REPLACEABILITY
EUCALYPTUS
Eucalyptus globulus
Replaceability as key to surviving When a tree or shrub is cut down or destroyed by either another organism or a destructive natural force, such as fire, the plant itself is usually killed. For Eucalyptus kochii plenissima, however, this is not the case. Due to a special root adaption called a lignotuber, absent in most other plants, this species can regenerate after the aboveground part is destroyed.A lignotuber is a special swelling at the top of the plant's root system (which sits mostly submerged below ground). It contains starch, sugars, nutrients, and meristematic foci. These contents enable the plant to regrow its shoots. The key to the process, however, lies in the meristematic foci. Resembling little pimples, meristematic foci are similar to stem cells, with undifferentiated cells and tissue that ultimately grow and change into new shoots. The meristematic foci, however, cannot act alone, and this is where the starch, sugars, and nutrients within the lignotuber come into play. The nutrients and sugars are broken down and used by the plant to grow and regenerate. The starch is used for respiration, just as it was used by the plant before the leaves were destroyed. Respiration brings in carbon dioxide, which is necessary for the plant to function, just as humans need oxygen. To increase the energy available to the plant for shoot regeneration, Eucalyptus kochii plenissima sheds most of its root system. By shedding unnecessary roots and leaving only the structural roots needed to anchor the plant, the energy previously used to maintain the extensive root system is made available to regenerate the parts above ground. Thus, the lignotuber of Eucalyptus kochii plenissima acts almost like a plant seed, containing all of the necessary cells, tissue, and energy reserves needed to regrow the damaged plant.

REPLACEABILITY
Lingotuber First part is lignotuber, that is a part of root above ground containing a lot of minerals and chemical elements, so that when the tree is dead or burnt, new tree is growing from the same lingotuber.
Epicormic shoots Second part is epicormic shoots. They lie dormant inside a trunk until needed. They have regenerative function, so in case of lack of sun energy or damage of upper part they wake up and start to grow.
Serotiny Third part is serotiny. Their amount depends on condition of tree. So, when it is dying a trigger start to work, enlarging the amount of serotiny and launch them.

CONNECTION
LIMPET
Patella vulgata
Renewable glue Another mollusk, the limpet Patella, backs the magnetite cutting tips of its radula with silicon dioxide. Incidentally, mollusks renew their radulas from the back as they wear near the front much the way elephants renew their teeth." Most classes in the phylum of the Mollusca possess a radula, a flexible ribbon, located in the mouth cavity, on which are implanted several tens of transverse rows of teeth. The radula is used as a rasp during feeding of organisms living on rocky substrates. Through the continuous growth of the radular ribbon new rows of teeth steadily enter into the wearing zone, while at the same rate teeth in the last row break loose from the ribbon. The enhanced erosive capability of the radula is due to the presence of teeth with an upright standing, hard, mineralized cusp.

VENTILATION
TURRETS' NESTS
Formicidae turret nest
outflow inflow
outflow
Surface wind is used to ventilate the turrets' nests.
Underground nest ventilation Surface wind, drawing air from the central tunnels of the nest mound, is observed to be the main driving force for nest ventilation during summer. This mechanism of wind-induced ventilation has so far not been described for social insect colonies. Thermal convection, another possible force driving ventilation, contributed very little. According to their predominant airflow direction, two functionally distinct tunnel groups were identified: outflow tunnels in the upper, central region, and inflow tunnels in the lower, peripheral region of the nest mound. The function of the tunnels was independent of wind direction. Outflow of air through the central tunnels was followed by a delayed inflow through the peripheral tunnels. Leafcutting ants design the tunnel openings on the top of the nest with turrets which may reinforce wind-induced nest ventilation.

MOISTURE PROTECTION
PINE CONE
Pinus lambertiana
Pinecone opens not only as a response to moisture level but also to release the seeds.
Response to humidity The scales of pine cones flex passively in response to changes in moisture levels via a two-layered structure. During the lifecycle of the pinecone, it opens and closes during different points of its life, often dependent on the conditions which surround it? For instance, the pinecone scales grow in order to protect its seeds after being fertilized. Then, those scales close to allow for the seeds to develop. Once the seeds are ready, those scales will open to release the seeds, allowing them to fly away as far as possible.What makes this even more amazing is that when the weather is moist, those same scales remain closed (so the seeds cannot escape). But when the weather is dry, those scales open to ensure that the seeds are leaving at the right time. You see, when the weather is dry those seeds can travel furthest as they are not weighed down.

BIBLIOGRAPHY
Biomimicry, Janine M. Benyus Nature, mother of invention : the engineering of plant life, Felix R Paturi On growth and form, D'Arcy Thompson Three crops, a permanent agriculture, J. Russell Smith. Origins of Form: The shape of natural and man-made things why they came to be the way they are and how they change, Christopher Williams. Biomimicry in architecture, Michael Pawlyn. Structure, Space and Skin, Nicholas Grimshaw & Partners The Power of Limits: Proportional Harmonies in Nature, Art, and Architecture, Gyorgy Doczi Zygote Quarterly (bio- inspired magazine)
https://asknature.org/ http://www.biourbanism.org/ http://slimoco.ning.com/
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