A View on Bio-inspiration

1.1 Introduction

Bio-inspiration is not a new concept; the human race throughout its history has looked to the environment for inspiration. Many of the tools and concepts we use today have their provenance from the natural world, for example flight and birds, dogs' noses and sensing, and vision and cameras. However, there is a growing body of thought worldwide that bio-inspired or bio-derived approaches can provide a wealth of innovative solutions and that the applications of biotechnology will play a predominant role in the next 'technical revolution'. In fact, biotechnology and bio-inspired approaches can help meet the many challenges of defence and security, not only in such areas as situational awareness, surveillance, network centric operations and protection/performance but also in many civilian application areas.

Bio-inspired Materials and Sensing Systems explores how we can learn from Nature to provide new approaches to solving some of these challenges. In particular, the concerns regarding terrorism1 are well founded as graphically demonstrated with the events of 2001 in the United States (US) and subsequently in the United Kingdom (UK) in 2005 and further incidents in various parts of the globe.

This is not an exhaustive study as the subject is extremely wide and varied and there are many researchers already carrying out excellent work in discrete areas. Furthermore, the increasing number of publications in a variety of journals illustrates the growing awareness of an interdisciplinary approach to this fascinating field. To illustrate this, an appraisal of patents published between 1985 and 2005 showed that whilst the total number of patents increased over the period examined, those with biomimetic content had increased faster as a proportion of total patent publications. There are also many excellent references available on specific areas (i.e. biosensors, biomaterials, etc.). Our goal is to provide an overview of how bio-inspired/-derived approaches can be used to enhance components, systems and systems of systems for defence and security applications. This book aims to provide a wider perspective of ongoing work in these areas and focus on structures, sensing, power, processing and potential applications.

1.2 Context/Motivation

Why are we looking at the natural world for inspiration and in particular biological organisms? Biological organisms use readily available natural materials to assemble highly functionalized structures, sensing and processing systems. They have evolved packaging that is relevant and appropriate to their environments in terms of physical structure, physiology, repair, sensing and processing attributes along with a whole series of survival strategies. In addition, through successive generations, the ability to transfer genetic coding relevant to the next generations provides an adaptive capability. The motivation, therefore, is to use biotechnology, bio-inspiration and advances in our understanding of biological processes to lead toward the development of new materials and artificial sentinel systems that can confirm the exposure to a wide range of unknown toxic materials.

To fully understand and learn from Nature, the importance of an inter-disciplinary approach cannot be stressed enough. In fact, interdisciplinary research in biotechnology and the related scientific areas has increased tremendously over the past decade. This pace of growth, in conjunction with advances in micro-fabricated systems, computer hardware, bio-engineering and the availability of low-powered miniature components, has now made it feasible to design bio-inspired materials, sensors and systems with tremendous potential to meet many of today's challenges. The defence and security areas are well suited to this type of approach as the output may enhance the paradigms in the way we sense and process information from the environment.

1.2.1 Bio-inspiration

What do we mean by bio-inspiration, especially when it is currently the fashion to put 'bio' (the abbreviation for biology) in front of a range of technical terms? Bio-inspiration is often referred to as biomimicry or biomimetics. It is therefore important that biomimicry/biomimetics and bio-inspiration be defined:

Biomimicry (from bios, meaning life, and mimesis, meaning to imitate) is a relatively new science that studies Nature, its models, systems, processes and elements and then imitates or takes creative inspiration from them to solve human problems.

Another definition of biomimicry is: a conscious strategy by designers to observe and learn principles of design from Nature.

Biomimetics (as already mentioned above) is the word most frequently used in scientific and engineering literature to indicate the underlying biological paradigms present keeping each species functioning in its own unique way.

Bio-inspired relates to ideas inspired by mechanisms or laws operating in biological organisms (e.g. neural networks).

Other descriptors frequently encountered include:

Bio-derived materials are materials made from or originating from living organisms.

Bio-fabrication is a process using cells, viruses, proteins, biomaterials and bio-active compounds as building blocks to fabricate advanced biological models, medical therapeutics and non-medical biological systems.

Bio-inspiration (although purists prefer the term 'bionics') in reality is a term that is all embracing as it covers all aspects of Nature. It allows us to follow Nature by using natural or other materials such as polymers and ceramics.

From an engineering viewpoint the term biomimetic (accredited to Otto Schmitt in the 1950s) has been used for describing how ideas from Nature can be used for engineering purposes. Bionics is a term attributed to Jack Steele at the US Air Force Research Laboratory at Wright Patterson Air Force Base in Dayton, Ohio. It is used to describe the application of processes, structures and systems found in Nature to engineering and technological developments.

The report on Biomimetic Engineering for Space Applications notes that Gustave Eiffel was inspired by the structure of the human femur (thigh bone) when designing the flared shape of the Eiffel Tower. The design was based on observation of the lattice work of tiny ridges of bone (called trabaculae). The arrangement of the trabaculae provided an effective way of supporting the mass of the structure. The iron curves of the Eiffel Tower were based on this principle, such that the structure of the tower could withstand the shear and strain forces due to wind flow.

Currently, we refer to bio-inspiration as a model that allows us to either copy or adapt Nature's processes. Biological systems are able to sense many stimuli, such as light, sound, heat, pressure, chemicals (pheromones for...