Here are some necessary steps in biomimesis:
- Identifying the Specific Function to be Developed (choose what is “gold” for you). In every mechanical system we develop, there are some particular processes that must be studied in particular, in contrast to other processes that are well understood. Identifying these will lead us in the second step, in selecting the types of animals and organisms that we must study.
- Gathering the Material (digging through a lot of “dirt”). This requires perseverance, patience, and good sources. One must develop the necessary knowledge to understand the biological processes at work in sufficient depth.
Remember that when you read material you must have specific questions in mind, so you select what you need from tons of unnecessary information.
- Classifying the Material. Animals perform many functions. Their behavior is partially influenced by processes unrelated to the function under study. For example, fish must feed and their mouth is developed to obtaining food. If we attempt to understand streamlining, we must also discard the shape of the head as being influenced by unrelated functions. It is particularly important in this classification of the information to find independent species that have developed similar traits—or the opposite, i.e. different species that have developed dissimilar functions with equal success.
- Imitating Nature. Remember that imitation of nature is Not the goal; the goal is to imitate its performance. But, often the first step in understanding is imitating. We will often try and construct a system that imitates the form and function of the animal world. This will hopefully make us understand the necessary from the unnecessary parts, and hence understand the basic principles hidden within complex behaviors.
- Technology Assessment. When we imitate nature we may find that technology is lacking when trying to replicate live animals. For example, we do not have good muscle-like actuators yet. This leads us to either abandon imitation where technology is not available, or develop novel technology if feasible.
- Final Design. The final step is to decide whether new principles have been learned, and if so whether the technology is available to implement them. Implementation does not mean imitation because once principles are mastered there may be totally different ways of applying them.
The Ultimate Success of Biotechnology is not in Replicating Animals, but in Replicating their Performance When it is Outstanding.
A Simple Example
Assume that we know little about fluid mechanics and we intend to construct a fin to be used for controlling the motion of a fast submarine. Shape is the first important consideration, both in outline and in cross-section. Should the fin be paper-thin? Or should it be very thick?
Somehow intuitively we feel that it should be “streamlined’’, i.e. thin in the transverse direction so it does not create large drag, but how thin? Looking at a variety of fins from whales to smaller fish we find that indeed all of them are streamlined (thin), but with a remarkable property: Almost all of them have a cross section in the direction of the flow which has the shape of a NACA profile. The precursor to today’s NASA (National Atmospheric and Space Administration), called NACA (National Advisory Committee for Aeronautics), developed a number of “optimal” wing shapes after considerable work. One of the most often used shapes is the NACA-0012, which is shown in the attached figure.
As Theodore von Karman, one of the leading scientists in mechanics and fluid mechanics in the first half of this century, noted in his book “Aerodynamics’’ (1963), the profile of another NACA profile, NACA63A016 is almost identical to the profile Sir George Cayley had found for a trout in the year 1810, about a hundred years earlier than NACA.
Another interesting point: Birds have also wings that conform to the NACA shape. World War I (bi) planes, however, had paper-thin wings. It took several years to discover that a thicker wing, as used in all aircraft today, is far preferable to a thin wing, how about the rest of the wing shape, the outline? Here there is a great variety of shapes depending on the function and a great classification must be studied depending on the desired qualities.
