Innovative Technical Creativity Methodology for Bio-Inspired Design

Part 7: TRIZ Combined with other ApproachesInternational audienceThe present research primarily focuses on building an effective rationalization of the knowledge which can be extracted from biological experts. To achieve such results, a structural framework, allowing knowledge integration from different fields at specific phases of the creative process is proposed. The formalized methodology along with its associated frameworks relies on principles from C-K Theory, TRIZ, and their links with biologically inspired design.To assess such design process methodology, an initial application within a case study has been implemented. This case study has been conducted through an industrial partnership with a Research & Development service department from a company working in the offshore oil production sector.But more than the concepts themselves, this new approach of biologically inspired design has emphasized, within this study case, an interesting potential in its propensity to quickly guide designers in accessing the most relevant knowledge from the biological field

Visualization of the internal structure of Didymosphenia geminata frustules using nano X-ray tomography

For the first time, the three-dimensional (3D) internal structure of naturally produced Didymosphenia geminata frustules were nondestructively visualized at sub-100 nm resolution. The well-optimized hierarchical structures of these natural organisms provide insight that is needed to design novel, environmentally friendly functional materials. Diatoms, which are widely distributed in freshwater, seawater and wet soils, are well known for their intricate, siliceous cell walls called ‘frustules’. Each type of diatom has a specific morphology with various pores, ribs, minute spines, marginal ridges and elevations. In this paper, the visualization is performed using nondestructive nano X-ray computed tomography (nano-XCT). Arbitrary cross-sections through the frustules, which can be extracted from the nano-XCT 3D data set for each direction, are validated via the destructive focused ion beam (FIB) cross-sectioning of regions of interest (ROIs) and subsequent observation by scanning electron microscopy (SEM). These 3D data are essential for understanding the functionality and potential applications of diatom cells

The Role of Surface Chemistry in Adhesion and Wetting of Gecko Toe Pads

An array of micron-sized setal hairs offers geckos a unique ability to walk on vertical surfaces using van der Waals interactions. Although many studies have focused on the role of surface morphology of the hairs, very little is known about the role of surface chemistry on wetting and adhesion. We expect that both surface chemistry and morphology are important, not only to achieve optimum dry adhesion but also for increased efficiency in self-cleaning of water and adhesion under wet conditions. Here, we used a plasma-based vapor deposition process to coat the hairy patterns on gecko toe pad sheds with polar and non-polar coatings without significantly perturbing the setal morphology. By a comparison of wetting across treatments, we show that the intrinsic surface of gecko setae has a water contact angle between 70–90°. As expected, under wet conditions, adhesion on a hydrophilic surface (glass) was lower than that on a hydrophobic surface (alkyl-silane monolayer on glass). Surprisingly under wet and dry conditions the adhesion was comparable on the hydrophobic surface, independent of the surface chemistry of the setal hairs. This work highlights the need to utilize morphology and surface chemistry in developing successful synthetic adhesives with desirable adhesion and self-cleaning properties