Is traditional engineering the right system with which to manipulate our world?
Submitted by sis on 09 March 2007
Engineering is probably humankind’s greatest achievement. And like all high-profile activities, it is in danger of becoming our downfall. It’s not that we are too good at it, it’s that we hardly realise that there are alternatives. A new study which compares engineering and the living world as problem-solving systems suggests that we have the tools for sustainable living, but are not using them properly (Vincent et al., 2006). We don’t necessarily have to go down an overtly ‘green’ path, but we need to reorganise current techniques with a different emphasis.
However, whereas individual species of animals and plants each have only a few adaptations, and so are found in well-defined habitats, humans can assume a wide variety of survival mechanisms, changing them as the environment changes. Thus, humans are not limited in climatic range, and have overrun the Earth. However, current methods of providing protection or isolation from the climate, such as houses, heating, air conditioning, waterproofing and protection from floods, are energy expensive, accounting for nearly half of our current energy usage.
In recent years, members of our research group have been comparing strategies to see whether biology has better or different solutions to the problems of survival. To do this, we used a collection of 40 ‘inventive principles’ which Genrich Altshuller, a Russian inventor and thinker, devised to represent the manipulations by which engineers solve problems. He and his colleagues gleaned these by studying successful patents, categorising them in terms of the problem that had been solved and the means of solution. The list forms part of a problem-solving system called TRIZ (Altshuller, 1988).
A problem arises if you want something, but you are prevented from achieving this desire. Plato pointed this out several thousand years ago. Altshuller also realised this, but reformulated and formalised the idea by producing a list of categories that covered all possible results and their conflicts. He then showed that a good invention is successful because it resolves a conflict with a new concept rather than with a compromise that satisfies nobody. Significantly, he listed the ways – the inventive principles – by which the conflict could be manipulated in order to achieve this resolution.
All this was a bit complex for us in our aim to compare biology and technology. Altshuller had help, and together they analysed some 3 million patents. We had less time and fewer people, so we simplified his system, and stated that there are six basic things that we can change in order to resolve a conflict. These are:
Nonetheless, when we saw that biology relies on changes in energy no more than 5% of the time, we realised that this is an important difference. In biology, change is effected by imbuing everything with information, starting from the DNA molecule. The proteins that DNA encodes also contain that information and allow the organism to interact with its environment, which represents another source of information. Proteins and their products then interact and ‘self-assemble’ in defined ways to form organelles, tissues, organs and organisms. The ordered arrangement of these levels of organisation, and the behaviour of the resulting organisms, all rely upon their embedded information and reflect it in the patterns that we observe. None of this occurs in the standard methods of engineering, although the idea of self-replicating machines has been around for some time. Adrian Bowyer, a member of our team, is running a project in which the computer programme for making a rapid prototyping machine can be downloaded from the Internet and read by a rapid prototyping machine. This machine will then be able to make a copy not only of itself, but also of (notionally) anything else. More details of this disruptive idea are available from the RepRap websitew1. Nevertheless, all patterns in the manufactured world are the result of conditions imposed by an engineer at some level.
Another difference is that technology is very reliant on materials – for instance, we use over 350 types of polymer in engineering. Biology has just two – protein and polysaccharide. But these are so variable, because of the information they contain, that they can achieve more than any manmade polymer. That information allows them to self-assemble into structures, such as the cell wall of a plant or the cuticle of an insect or lobster, which provide yet more functional versatility. In addition, with only two polymers to deal with, recycling is relatively easy. Current waste reclamation allows us to separate only about six polymers (Table 1) with any reliability. But these six represent most of the functionality we require. Why do we have so many polymers? We should select our materials for their ease of sorting and recycling. Their functionality can be increased even further by copying nature and assembling them into structures such as foams and honeycombs, or combinations and permutations of such structures.
Table 1: The six separable plastics
We are only at the beginning of the study of biomimetics and how to make the best use of the technological tricks we can learn from biology, but already we have discovered ways to challenge technology and revealed ways that biological organisms – the great survivors – answer the same problems in a sustainable manner. Now we have to set about changing technology to ensure our survival – although humans have successfully colonised a wider range of environments than any other species, they have done so in a very inefficient way, at enormous environmental cost.
Classroom activity: A biomimetic challenge
Get your students involved in biomimetics! Here are two challenges from the Science in School editor:
Send us your ideas and/or pictures by 30 June 2007, and we will publish our favourite entries together with Professor Vincent’s responses. Don’t forget to tell us your name, age, school and country. Include the text ‘Biomimetics challenge’ in the subject line of your email and send it to: email@example.com
By reading this article you will learn some new synonymous terms: biomimetics, biomimicry, bionics and bioinspired design. They are all words describing how living creatures are used as models or inspiration for engineers when developing new materials or constructions. Animals and plants are very well adapted to their environment because they have solved challenges related to their survival, for example isolation from extreme heat or cold. They have evolved materials and strategies which are very well suited for certain aspects of their life, such as reproduction, feeding, protection and so forth. Professor Vincent gives us examples of so-called biological tricks that can be useful in engineering. By comparing basic elements within biology and technology, scientists and engineers will achieve a better understanding for resolving their problems. There are plenty of things we can learn from nature!
Don’t forget to study and involve your students in the two challenges at the end of the article!
w1 – RepRap website
For an example of recent biomimetic research into spider silk, see:
Cicognani G, Capellas M (2007) Silken, stretchy and stronger than steel! Science in School 4 : 15-17.
Professor Julian F. V. Vincent is the director of the Centre for Biomimetic and Natural Technologies at the University of Bath, UK.