With the advance of science and industry, we learn day by day that, in many different fields, the best of things can be expected from nature: the best materials, the best medicine, the best conditions of life, the best structures. For this reason the attention of specialists has been drawn to the superior structures of nature — structures such as the trunk of a tree, animals, and, finally, the human being; the stability of the mountain because of its shape and form; the resistance and steadiness of the tree, which with a very high slenderness ratio can stay stable against lateral forces such as the wind; or living beings, and in particular the human being, who can, through a large number of hinged connections, achieve a fitting balance and standing.
Amid all this, what the advance of computer science is bringing the human mind slowly to consider is that one of the principal factors of stability in a structure, besides the laws of statics, is the degree of intelligence in that structure. A tree, for instance, when the wind is blowing, contracts its roots — which grip the earth like a claw — and hands its trunk over to the wind, so that it may sway in the current and, in truth, acquire greater flexibility. A human being who is standing in a moving bus slightly bends his knees in order to gain balance, and takes hold of the seat rail with his hand in order to prevent lateral motion — thereby, in truth, strengthening his lateral support. In this state, the muscles of the legs and arms contract and raise the resistance of the supports; on the other hand, some of the muscles of the body, such as those of the back, slacken so that the jolts of braking and the like do not put the joints to pain.
By the principle that in a structure the forces follow stiffness, the forces produced in the structure of the body are drawn to those points that have greater contraction; and, since the sum of the forces is a constant number, a smaller share reaches the softer points of the body.
Pyramid-shaped buildings — the pyramids of Egypt or those of South America — are among the most stable of building forms and have a particular resemblance to the mountain. Likewise, in recent years one can observe reputable buildings that have been designed and built with an inspiration drawn from nature, such as the Kansai Airport building, which was designed on the model of the skeleton of a dinosaur.
What has perhaps not yet been carried out in practice is a structure that, while holding the form of a natural structure, also carries within itself its intelligence. But now, with the help of microprocessors, we can undertake to bring awareness into a structure, and alongside it to produce members that have the capacity to change.
For further acquaintance with this technology, here follows a translation of an item from Architectural Record (no. 11, 2000):
A scientist at Xerox has found a way to create organic members inside the building.
Imagine a building that can sense the shocks of an earthquake and at once turn itself into a tree-like, flexible structure and so bear the shock it receives. Or imagine a bridge that can perceive the destructive force of a storm and, in real time, reinforce its piers in such a way that they withstand the forces brought upon them. Or imagine a car able to detect a fundamental fault in its engine and at once produce a reaction meant to lessen the technical defect.
One of the scientists of computer science at the research centre of Xerox Corporation in Palo Alto, in the United States, by the name of Feng Zhao, has been engaged for some time in research into such intelligent structures and holds that such structures will soon be among the items of daily use.
Zhao and his colleagues at the Palo Alto centre are designing a system of small, cheap sensors capable of detecting the surrounding information — such as heat, light and vibration — and of exchanging it with other sensors scattered throughout the building, whose number may rise into the thousands and even into the millions. This vast network of sensors can, at once, analyse the gathered body of information and produce, almost instantly, a fitting response in the structure.
In the case of buildings resistant to the force of earthquakes, such a response can take the form of sending electrical signals to materials made of alloys with shape memory, already placed among the elements of the building's skeleton, so that they expand or spread out and raise or lower the flexibility of the different points of the structure during the swings of the earthquake. The same act can take place in the structure of a bridge as well, during the occurrence of a storm.
These sensors are placed inside and around the building and are able to detect what is going on around it — a current of warm air, movement and the like — and to react of themselves. What distinguishes these sensors from a thermostat or a thermometer is that they carry within themselves advanced software that enables them to put the gathered information in order and to share it, in an organic manner, with other sensors; so much so that one can see a likeness between these sensors and the neurons of the human brain.
It should be noted that these sensors are not connected to an information bank in a central computer; rather, each small sensor has a memory of its own, and every set of sensors that has been placed together forms a "super sensor" with fuller information about that region of the structure. This set of sensors, just like the human brain, is able to throw away unimportant information and to use the important. In other words, the sensors are mostly asleep and wake only when a noteworthy event occurs about them.
At present, the Xerox company produces sensors the size of a 25-cent coin. In the coming 5 to 10 years, Xerox expects, on one side, to bring the sensors down to the size of a lentil, or even smaller, and, on the other, to raise their power and efficiency. To grasp the point, one should know that in a building the volume of informational operations conducted by sensors will be far greater than the volume of information exchange on the internet. It is said that, for their price to come down, in addition to the 10 years mentioned, a further 10 years must pass. In the end, these sensors can be brought into the skeleton and sprayed over the structure.