Biomimetics (the transfer of functional principals from living systems into designs) is a rapidly growing field of research. Nevertheless, gauging how useful it has been as a tool for developing new products and technologies is difficult, as the field is currently ill defined and real, tangible outputs have so far been few. Moreover, it is questionable if it is producing true engagement across the scientific, engineering and design disciplines.
Given the current state of the discipline, we (see Wolff et al. 2017. Bioinspiration & Biomimetics: http://iopscience.iop.org/article/10.1088/1748-3190/aa86ff) have critiqued the field and suggested ways forward to improve outputs and engage more cross-disciplinary researchers.
In our review we offer:
(1) A clear definition of biomimetics as “the transfer of functional principals from living systems into designs”. There have been definitions offered before but they have suggested that the ultimate goal be to ‘mimic’ or ‘copy’ natural processes, which is not realistic, nor (in most instances) valid.
(2) A distinction between the design and engineering processes and natural processes, such as evolution by natural selection. We consider this important as a misunderstanding about the processes and outcomes of evolution by natural selection appears to be a significant factor affecting the success of biomimetic programs.
(3) A detailed synthesis of 3 popular biomimetic endeavours: (i) the design of reversible adhesives based on gecko toe pad properties, (ii) the development of high performance materials based on spider silk tensile properties, and (iii) the engineering of digital and other systems based on the principals of swarm intelligence in ants.
For each of the above we outline the working principals of the natural phenomena and how the biomimetic principals are generally being developed, and offer an appraisal of the functional and mimetic success of the designs developed thus far.
We thus concluded that:
(1) Exploring and testing single aspects of the natural model (be it the fibrillar structure of gecko toes or the protein composition of spider silks) in the absence of considering the organism as a whole with operating feedback systems, competing structures, and interactions with the environment, results in ineffective designs.
(2) A lack of well-defined working principals, including the timeframe and generality over which the functional properties of interest are expected to operate, results in unsatisfactory designs.
We recommended that:
(1) The target function must be specified from both a biological and engineering perspective. This includes identifying the problem/question in a top-down and bottom-up manner, and investigating and outlining the various complexities associated with the function.
(2) The underlying working principals must be defined across multiple contexts and hierarchical scales to ensure that key features affecting the function of a structure are not being ignored.
Modelling (e.g. using finite elements), prototyping, and comparative analyses are tools that should be incorporated into biomimetic programs.
(3) An appropriate natural model should be selected. This will involve identifying and testing the functions of different viable alternatives. This is likely to be time consuming and difficult since engineers, designers and biologists cannot know all the viable alternative models. Thus the establishment of a biomimetic database that details the traits of various models might help researchers identify the most appropriate model(s) for a specified purpose.