Years of research has revealed that nature applies certain underlying principles in a spectacular variety of imaginative form. In this way nature:
1) Economizes the use of materials
2) Maximizes structural strength
3) Maximizes the enclosed volume
4) Produces extremely high strength-to-weight ratios
5) Utilizes stress and strain as a basis for structural efficiency
6) Creates energy efficiency through form without external power
7) Creates form that enhances air circulation
8) Uses local materials for building
9) Uses curvilinear forms that disperse and dissipate multi-directional forces
10) Integrates aerodynamic efficiency with structural form
11) Produces nothing that is toxic to the environment
12) Designs structures that can be built by a single organism
Our research comes from many different sources and are by no means all our own. Many people have studied to a tremendous extent the way nature grows, builds, and evolves. Most of what has been done can be found at a good university library. But rarely do the scientists and explorers use this knowledge to influence our understanding of design and the way we build architecture. This is what Tsui Design & Research Inc. is trying to do. We are engaging in research and the development of technology that stems from a scientific understanding of how nature evolves into the forms and structures we see ( or don't see). Nature never creates without a functional purpose, and the forms and patterns are rarely only for visual beauty.
We hope these pages are inspirational, educational and provide a general understanding of nature's building systems. There is still much to be understood and it is our belief that through understanding more about nature, we will learn more about the present and future roles of humanity.
Truth is always or more terrifying than imagination.
The termite is the acknowledged master architect of the creature world. No other insect or animal approaches the termite in the size and solidity of its building structure. The world's tallest non-human structures are built by Australian or African termites. If a human being were the size of an average termite, the relative size of a single termite nest is the equivalent of a 180 story building--almost 2000 feet high. It would easily be the tallest building in the world. How is it possible that this tiny creature has the engineering know-how to erect an edifice of this magnitude? Obviously this knowledge is innate to the termite. The process of construction, the materials and correct combination of materials to yield an elegant, structurally efficient and durable structure is simply awe-inspiring.
The building material is usually local soil mixed with saliva. Sometimes dung is mixed in. It becomes so hard and impervious that the native people of the area use it for building their mud and stick shelters. The termite mound, or termitary, consists of hard, thick walls that seal in moisture and keep heat out. The Australian and African variety of termite towers are designed for cooling. A system of channels and ducts circulates air through the mound. These passageways run through areas of the mound that have walls that are porous or have tiny ventilation holes. The pores act as fresh air ventilation and stale air exhaust. This supply and return system performs solely on heat and gravity with no moving parts. Can our tall building work with such efficient simplicity?
At the lower core of the termitary are the living and working quarters. This area is the coolest and most insulated zone of the nest. The royal chamber, which is the largest chamber in the nest, houses the queen and king. Below the royal chambers are where the workers store food and care for the young termites, called nymphs. In some colonies the workers tend gardens where tiny mushrooms and varieties of fungus are grown. The termites grow this fungus inside a comb which is located in several pockets in the central zone of the inner nest. The comb, made of termite droppings, provides nourishment for the growing fungus and the termites feed on both the fungus and the comb. Termites live on cellulose, the substance which makes the framework of vegetation, and fungi.
Ingress and egress from a termite tower is provided by a series of underground tunnels. The tunnels lead outward and branch into a network of passage that open to the outside. The insects make their trips to the outside at night, when it is cooler, and collect twigs, leaves, seeds and other food. In very hot, dry climates some species in the desert dig straight down exceeding 125 feet(38m) to connect with underground water. Underground wells supply the termitary with water and a source for cooling the interior. The peaks and towers of the termite's nest act as lungs that expel rising hot air, which is generated by the breaking down of the fecal comb by the fungus. The air then rises via a large central air duct, and moves up through the long porous chimneys.The carbon dioxide in the air then diffuses to the outside, while oxygen diffuses into the chimneys. The oxygenated air eventually loses its heat to the cooler outside air and cools sinking down into the cellar. Such an ingenious HVAC system is necessary for the survival of some three million termites to a single colony.
The exterior form of the termite nest depends upon the climate. For instance some termite nests have adapted to their rainy surroundings by creating umbrella-like roof structures that direct water from heavy rains away from the nest. Compass termites appear like giant wedges with the broad side facing due east and west. This solar orientation serves to keep the high, intense sun from hitting any appreciable portion of the mounds surface and allows the weaker morning and setting sun to warm the greater surface area of the structure; thus, the structure attempts to create an even heating situation whereby the mound does not overheat.
THE TARDIGRADE: NATURE'S MOST INDESTRUCTIBLE CREATURE
The tiny tardigrade, whose size is no larger than the head of a pin, has proved to be one of nature's toughest survivors. Laboratory experimenters have immersed it in liquid helium down to a savage -272 degrees Celsius. They have left it at -192 degrees Celsius for 20 months, and cooked it for a week at 92 degrees Celsius in ether, alcohol and other noxious chemicals. Restored to normal temperature and given water, the tardigrade strolls away. Some specimens were brought back to life after 120 years in a dry and dusty museum.
Obviously the tardigrade has abilities human beings lack. Tardigrades dwell in mud, damp seashore sand, or on the water film surrounding the leaves of mosses and lichens. Some varieties are entirely aquatic. Zoologically they fall somewhere between worms and insects and can move about by wriggling on four pairs of stubby legs. There are tardigrades worldwide except in the tropics and Antarctica. A single gram of dried moss has been known to yield 22,000 of them.
How does this soft-bodied creature have the unique ability to switch itself off and on under extreme circumstances--enabling it to spread a normal lifespan of 18 months over some 60 years? How does this armored arthropod last so long? One reason may be its shape--an oval or ellipse, and its series of flexible shell-like body pieces,.
BEAVER--MASTER MOUND BUILDER
Of the order of rodents the beaver is one of the most cleaver. Nature has equipped the beaver with a set of tools that makes its architectural achievements possible. Just as the materials and methods of construction in human-made architecture enable us to evolve our buildings to achieve great feats of engineering and show us new possibilities in form, so the tools and materials of the beaver create the circumstances by which it can create the mound design of which it is famous.
The beaver is one of the heaviest rodents, weighing up to 70 pounds, and can stay submerged underwater for up to fifteen minutes. Its webbed hind feet and broad tail, which it uses as a rudder, propel and steer the animal through the water and are also tools for construction. Beavers are experts not only in building dwellings but also in hydro-engineering.
Beavers vary their dwellings according to local conditions. The inner chamber of their mound dwelling is positioned according to the level of the river in which it is situated. Once the mound is built the water rises up to meet the lodge. During construction, they dig an upward sloping tunnel into the riverbank which culminates into a larger subterranean chamber about three feet in diameter and two feet high. There is also usually a feeding chamber located near the entrance. Feeding generally occurs at night inside this chamber or outside on the river's edge, and all leftover scraps from feeding are disposed of directly into the water.
The beaver has designed its own version of an HVAC (heating, ventilation & air-conditioning) system; most of the mound structure is carefully sealed with mud and clay, but part of the upper dome superstructure is left with hollow openings for ventilation. During cold weather small clouds of steam can be seen rising from the tops of beaver mounds.
The specifics of mound building are remarkable. Strong, stout timber is placed onto the bottom of the stream or river bed, creating a "wall" that is built up from the river bottom. Pieces are interwoven throughout and forked branch pieces are then placed between the dam wall and the river bottom supporting the structure against water current. Cross pieces or stakes are often inserted for additional resistance.
An alternative strategy is to anchor the structure to existing trees or boulders and further brace these by heavy stones brought to the site. Gaps in the wall of the dam are filled with small twigs, reeds, leaves and other small materials and covered with mud or clay to make the dam completely watertight. The walls of the underwater entrance are smooth and steep. In front of the entrance is an ingenious deep pit where materials are gathered. The pit also acts as a water current buffer by reducing the speed and destructive force of the water, protecting the structure. The downstream wall is composed of coarse branches anchored laterally for additional bracing. The crown of the dam is hydrodynamically designed to be lower at the edges to allow water to flow over near the banks.
Acoustics is a very important consideration in dam construction. For some reason beavers instinctively seek out those places in a river where the water is rushing noisily, for example between stones or where there are dips. A smooth surface is necessary for the water to run over the dam quietly, so the beavers place branches and mud in that space in order to level the area. When the dam is essentially level, the water-now obstructed-rushes past on either side of the dam creating another noisy depression. So the beavers fill in that space with material so that once again, they can make a level surface.The beavers end this process by placing finer materials such as mud and small stones in between the crannies of the twigs for a more compact and smooth surface.[d] When their work is completed, the water level will have risen and it will run quietly around the dam.
When the surrounding water level of rises, threatening its home, the beaver has several options. They can go to the source of the problem-the water- and lower the crown of the dam where the water runs over thus lowering the water level. If this does not suffice, they can gnaw off materials from the ceiling of the structure to build up the floor. Similarly, soil and twigs can be heaped together to create a thicker and higher floor level. If the water level continues to rise, more twigs and mud can be added to the original structure and the main chamber can be dug out further up, keeping the same angle of entry. In some areas, as in shallow, slow moving ponds, the beaver creates an island of branches, twigs and mud.If a hole develops in the dam they immediately find and repair the damage. Their mounds can reach a height of six to ten feet with hollowed-out living chambers inside, and entrances below water level. The largest recorded dam is in the Voronesh region of the former Soviet Union and measured about 3800 feet long, 3 feet high and wide. In the swamps of the Mississippi basin and the Jefferson river in Montana beavers build dams over a thousand feet long which are strong enough to carry a person on horseback!
In the winter, when the water surface is completely frozen, beavers have devised a method of controlling their environment. In places where the water is dammed up they make openings in the dam to allow water to flow out thereby lowering the water table underneath the frozen surface. This creates an airspace in the ice where they can breath and swim. The temperature inside is maintained at above freezing even when the outside temperature drops to -95 degrees Fahrenheit. Before winter sets in they cut down trees for storage. They collect large quantities of branches and brush which they anchor in heaps at the bottom of the water near their entrances. This stock pilling solves the problem of transporting provisions from great distances; or land to their living quarters.
Few species have the ability to manipulate the environment to their own ends as the beaver does. The dam, lodge, winter foodstore, canals and runways are all part of a completely designed environment. The beaver and its dam, which at first might seem to be destructive rather than constructive, have wide effects on the ecology of the surrounding countryside. The dam raises the water table and slows drainage at the base of the dam by maintaining a steady flow of water in headstreams. The dam also prevents soil from washing downstream. And the rich soil that builds up soon supports a variety of plants that will attract other animals. Similarly, the systems of dams and pools provide food and habitat to other creatures, which in turn attract predators and the whole web of life is enriched.
Once the stream has backed up and collected into a still pond and the lodge has been built, the beavers can regulate the depth of the water.The beavers' main task and principal means of survival, is to monitor the water level and maintain the dam. An enormous responsibility for the beaver when you remember that some dams grow to be a half-mile long! The commitment of labor to this kind of massive project:(cutting trees, trimming spillways, etc....) makes sense for the beaver only because the dam is meant to last forever. Beaver dams are maintained generation after generation by offspring of growing colonies. There are dams today that have been in use for over a century.
The beaver is the greatest animal architect and the strength of its structures alone is enough to verify its valued position. The lodges and dams are intelligently designed and well made. They incorporate materials difficult to collect and are combined into a coherent form. The functional mastery of hydro-engineering is unparalleled; certainly no other animal structure in the world has to withstand the rentless, elemental pressures borne by a beaver dam spanning a swift river. These dams and lodges work decade after decade, responding to adjustments, recovering from disasters and holding fast in form, function and purpose.
The dam building engineering of the beaver is another model worthy of study. Although the structural system used by beavers is generally understood and used in human dam building,a person wishing to build an economical dam structure from local materials could learn from the engineering process of the beaver. The use of trees to provide anchoring is a rarely used architectural concept. This method of structural anchoring could be used in tension structures to create suspended roofs or small buildings off the ground. There are quite a few examples of "tree houses" built in rural areas throughout the United States using the beaver's tree anchoring system.
Perhaps the greatest lesson we can learn from the beaver is its understanding of the natural environment and the non-destructive maintenance of that environment. The presence of the beaver dam has positive ecological effects which consider the entire environment as the design--not merely the issolated dam structure. The beaver dam uses only enough materials to serve the purpose(Principle 1), to create adequate structural strength to resist even the most extreme water pressure and flooding situations.
The hemispherical shape of the beaver dam expresses the principle of maximizing volume while minimizing materials (Principle 3) and surface area. This shape also distributes stress and strain loads throughout the structure(Principle 5) similar to an igloo. This goes hand-in-hand with the hemisphere's energy efficiency and air circulating ability described in Principle 6. The stability of the dome/mound structure is a sensible resolution to the constant water pressure and potential flooding of the area. The den shape is roomy and also durable. As indicated in Principle 10 the entire dam structure is built by a few beavers using simple procedures of construction. The beavers readily adapt to the specific features of the site and seem to innately proceed with a construction strategy based upon the immediate locale. As with all of nature's structures the beaver's den is both aerodynamic(Principle 8) and hydrodynamic. Air easily passes over the mounds drawing internal air with it and replenishing the dens with fresh air. In the water the dam provides a silent and smooth running mini-waterfall for regulating water levels and flow. The arched profile of the dam provides a perfect form for achieving this purpose.
Blades of tall grass serve as foundations for the nest of a spittlebug. The spittlebug builds its nest when it is young. The nest protects the young spittlebug's skin from the sun and helps hide it from predators. The bubble forms are made from a small pool of liquid. Then the bug introduces air into the liquid through a tube on the end of its abdomen. The air makes the liquid bubble up into foam. To make this bubble foam durable the spittlebug's kidney tubes adds a special ingredient to the liquid before the foam was made. The foam is present until the young spittlebug (nymph) develops into an adult--a process that takes 30 to 100 days depending upon the temperature.
The spittlebug is also called a froghopper. When the froghopper is fully grown it will have wings and legs capable of enormous jumps, but as a young nymph it has no defenses so it builds its house of durable bubbles in which to hide. This insect sinks its sharp beak into the stem of a plant or blade of grass. The plant juices that flow out are both its food and the material by which it builds. As the plant sap is taken in it flows throughout its body. Internal chemicals are added which change it into a soapy liquid. This liquid trickles from his tail until a pool collects under it.
The insect blows into the liquid with its abdomen It has a row of plates on his underside which open when it raises its tail and close when it lowers it. The froghopper uses its body like a bellows to make a stream of tiny round bubbles. As its tail moves up and down, the bubbles pile up until the insect is completely covered with the froth. It takes approximately 10 to 20 minutes to built the bubble home. The bubbles last for as long as a week and seem to repel predators, in fact, smaller insects are known to become permanently stuck to the sticky bubbles.
As with all of nature's artificers Principle 10 applies most aptly here. That is, a singular builder, armed with some basic skills, in this case, knot tying, braiding and grass weaving, can create a habitable structure of extraordinary lightness and strength,Fig.2.71. Although creating a building form from a weaving process has been limited to middle eastern and north African countries using long river grass strands bound together, bringing the weaving concept as a modern construction application is functionally possible.
Using thin strands of re-bar a building could be constructed by an inter-weaving method with all intersecting and overlapping points welded together to produce a wound armature of unprecedented strength and rigidity. Any flexible, lightweight material could be "woven" to produce a tensile structure based upon the weaverbird model. This results in a relatively lightweight structure that has uni-lateral tenuity as well as compressive resistance. Weaving a building is a method not commonly thought of in our western frame of reference. It is an approach that has great potential because, like the weaverbird, a few simple skills are all that is needed. Of course, where we humans are concerned, a building is more than its structure, it must have waterproofing, sheathing, insulation, plumbing, etc. The marvelous aspect of nature's structures, like the weaverbird, is that a few materials, grass, plant silk and twigs are all that is needed to have a wholly functional home.
Perhaps this principle of using fewer materials to create a complete "building" is in itself worth contemplation. It certainly includes many of nature's principles mentioned before. It is curious that the weaverbird is one creature that requires practice to perfect its construction technique. In this regard the weaverbird is similar to us--it must learn to build well.
The advantage of tension, overlap structures, like the weaverbird nest, is its ability to resist destruction. The typical "cut-and butt" framing approach of conventional architecture has little inherent resistance to being pulled apart as witnessed by the aftermath of hurricanes, tornadoes, earthquakes and flooding. Not surprisingly, bird's nests have been commonly retrieved from these catastrophes separated from their original location but completely intact--evidence of its superior tensile capacity.
Some of the strongest organisms in nature are overlap, tension structures; trees, plants, flowers, just about any fibrous structure relies on overlapping and a kind of inherent "weaving" within itself. This gives it the ability to transfer and disperse stresses without collecting loads in one place where it would weaken from the load. The weaverbird nest has no single area where stress and strain congregates; and that is its advantage.