Yoseph Bar-Cohen

Biomimetics: Biologically Inspired Technologies

CRC Press: 2006. 527 pp. £79.99 0849331633

One touch of nature makes the whole world kin — That all with one consent praise new-born gauds, Though they are made and moulded of things past, And give to dust that is a little gilt More laud than gold o'er-dusted.

Yoseph Bar-Cohen's multi-author volume Biomimetics, devoted as it is to a plethora of 'new-born gauds', has examples of gold coated in a variable thickness of dust. In defiance of Ulysses' cynicism in Shakespeare's Troilus and Cressida, there is only a little shiny dust on display here, and I suspect that readers will quickly brush it aside.

One of the chapters begins: “The field of biomimetics encompasses a broad range of topics, generally based on the concept of 'learning from Nature' in areas of Materials Science and Engineering (MSE). This 'learning' may be through inspiration in design, function or a combination of both.” Until I read this book, that was my impression of biomimetics too. However, only 5 of the 20 chapters are focused on aspects of MSE, particularly mechanical properties. One of these centres on 'muscles' made from electroactive polymers, and includes some irresistible pictures of a teenage girl arm-wrestling with a synthetic arm.

The rest of the book has a strong emphasis on robotics, both macroscopic and nanoscopic, no doubt prompted by the editor's attachment to the Jet Propulsion Laboratory in Pasadena, with its mission of space and planetary exploration. Synthetic eyes and associated electronics also receive extensive attention. There are two unusual but interesting chapters devoted to design and optimization procedures that imitate the processes of biological evolution. One of these chapters, on 'genetic algorithms', contains some intriguing examples of this procedure, one of which even incorporates an ingenious analogue of sexual reproduction. Another example involves the optimum locations of a group of post offices to serve a community as economically as possible, and another considers the dynamic balancing of a gas-turbine shaft. Generally, the book contains much control and optimization theory, some of it alarmingly mathematical. It should also be pointed out that most of the optimization procedures discussed make use of computer simulation, rather than physical modelling.

Some chapters include detailed examples of applications of the principles set forth, whereas others, no less stimulating, describe in depth the relevant features of nature but barely hint at specific applications, such as the chapter on defence and attack mechanisms in biology. Only one (very long) chapter, on the 'mechanization of cognition', seems to be 'gilded dust'; I cannot see that it contributes anything to the theme of the book.

Bar-Cohen himself wrote the substantial opening and closing chapters, and suggests the next stages of research. He also penned the chapter on synthetic muscle, one of his research specialities.

This book differs sharply from earlier treatments of biomimetics, such as R. McNeill Alexander's Animal Mechanics (Sidgwick & Jackson, 1968). Stephen Mann's Biomimetic Materials Chemistry (VCH, 1996), which I reviewed here ten years ago ( Nature 382, 684; 1996 ), focused on materials chemistry. An important subset of this theme is the chemistry and microstructure of high-strength composites, and also spider silk, which clearly exerts great fascination — there is also a chapter on silk in Bar-Cohen's book.

The focus on robotics and on optimization by evolution seems to be unique and constitutes the main claim of Bar-Cohen's volume to widespread attention. Another feature of the book is the extreme care he has taken to obtain the critical opinions of 66 experts, and their ministrations evidently contributed much to the book's clarity of presentation.