The Push and Pull Building System, Part 1

"Steady under strain and strong through tension,
Its feet on both sides but in neither camp,
It stands its ground, a span of pure attention,
A holding action, the arches and the ramp
Steady under strain and strong through tension."
Seamus Heaney, 'The Bridge'

     We see a lot of bio-inspired materials come from tiny forms, but humans were builders far before they were nanotechnologists. Along side the growth of bio-inspired material science is the rise of bio-inspired architecture called Zoomorphic. Famous architects have started to show Zoomorphic in their work including Will Alsop, Edward Cullinan, Norman Foster, and many more.
    The Zoomorphic exhibit created a discussion with architects and scientists on how deep the roots are between organic tendencies. Julian Vincent, Professor of Biomimetics at Bath University, says that he would like to see architects learn the principles of natural structures and apply it. He says that architects are now concerned with designing buildings that use energy efficiently. An example of this is the spiraling latticework of Norman Foster's Swiss Re Tower because the internal spiral wells provide natural ventilation. Designing these things comes with the same problem as designing bio-inspired nanotechnology which is building techniques that are form fitting.
    D'Arcy Thompson wrote about early links between nature and buildings. An early example is in 1851 when Joseph Paxton built the Crystal Palace. It is thought that he got the idea of ribbing from the Victoria regia, a water lily. Thompson pointed out how nature makes these structures by using the least amount of energy possible like a hexagonal pattern from wasps nests, and egg shells, where the whole structure is a curved surface.

    Since early human history the structures of houses were created brick by brick. The struggle came when the use of bridges were needed. Because of the force of gravity, a string or cable that is suspended off of poles will always have a sag in the middle. Building an arch was the solution to this problem. Isambard Kingdom Brunel made an arch bridge as a grand scale when the Great Western Railway had to cross the Thames. His design had the flattest arch in the world and many people thought that it would never work but it is still standing 150 years later.
    The Forth Bridge is a cantilever bridge, a structure that engineers share with nature: the backbones of quadrupeds are cantilevers. In the Forth Bridge the weight is equally balanced which makes it pretty stable. To have a good bridge you need equal parts on compression and tension. The Forth Bridge has some compression and some tension, but tension structures really only entered the builder's era with suspension bridges. The essence of a suspension bridge is to span the complete distance with two hanging cables and then to suspend the deck from these cables with smaller vertical cables.

    Another great invention in the world of architecture was reinforced concrete. Concrete and steel are complementary since concrete is strong in compression and steel is strong in tension. Having a steel grid inside of the concrete enables almost any size or shape to be cast in concrete. Concrete helped architects and engineers design nature's most organic structure: the shell. Heinz Isler has built more then 1,500 shell buildings by using natural forces to find his forms. Even though Isler was unaware of this, the results of his experiments came from the criteria of natural objects which puts them in the mainstream for bio-inspiration. Isler designs his shell buildings by scaling up from his original structure. Their delicacy makes them so unique, classical domes have a thickness/radius ratio of about 1:50. Natural eggshells have a ratio of 1:100. Isler's domes have a ratio of 1:800. Eventually, computers were able to copy this design very easily and that made Isler very angry.
                           Isler's shell design over a filling station on the Berne-Zurich highway

    Santiago Calatrava is currently the leading exponent of organic architecture. Calatrava is both an engineer and an architect . His most famous bridge is Alamillo Bridge. The bridge looks like a giant harp because it has giant cables suspended everywhere. He also designed the 2004 Athens Olympic Stadium. He is known for his beautiful but also extremely expensive buildings such as Zurich Railway Station, Milwaukee Art Museum, Campo Volantin Footbridge, and the Sundial Bridge at Turtle Bay.