ELiSE—An Integrated, Holistic Bionic Approach to Develop Optimized Lightweight Solutions for Engineering, Architecture and Design

Abstract

It is generally acknowledged that living organisms have developed powerful solutions for the challenges posed by environmental factors. These solutions are often more efficient than comparable technical solutions, as they are optimized by an evolutionary process (which takes millions of years) and elegantly integrate diverse functions in a single structure. In the case of stable lightweight constructions, such principles can be found among the exoskeletons of diatoms and radiolarians, which are the most prominent components among unicellular planktonic organisms.

Bionic transfer of such plankton structures to the technical world is, especially if developed by architects and designers, often based on an intuitive selection from the large variety of biological forms. The results—buildings, vehicles or articles of daily use—are beautiful and interesting, but often not really optimized, as systematic adaptations to the technical load cases are missing. In contrast, approaches developed by engineers extract mechanical principles of natural lightweight structures and transfer them to technical solutions. These solutions are usually adapted to the technical requirements (load cases, materials) but they still depend on arbitrary choices from the vast pool of biogenic structures. Therefore the results have a strong random component and it is not clear how well the lightweight potential of a certain object has been exploited. In contrast, natural lightweight forms, especially the shells of planktonic organisms (diatoms, radiolarians, coccolithophorids and acantarians) combine a strict adaptation to performance (mechanical strength, light weight and permeability) with a peculiar beauty, and exist in a large variety. Their adaptation to new challenges is achieved efficiently by the evolutionary process.

In order to achieve a similar degree of adaptation as is present in biogenic structures, the ELiSE lightweight process was developed as a systematic 5-step procedure: This includes (1) a precise technical specification of a lightweight component including e.g. load cases, materials, and manufacturing restrictions, (2) a selection of powerful archetypes identified from biological databases using similarity search algorithms and a mechanical assessment of these models using Finite Element Analyses, (3) the abstraction of natural design principles to digital concept models using CAD and novel tools, (4) a structural adaptation using optimization tools such as Evolutionary Strategic Optimization, and (5) the final design which combines bio-inspired structures, results of optimizations routines and realistic manufacturing methods to produce an optimized part. Here we show how the ELiSE method relates to the natural evolutionary process and discuss the characteristics of the results compared to conventional methods.