Mechanics of Slender Biological Structures

点击翻译按钮获取中文摘要

Slender structures are ubiquitous in our man-made world: aircraft wings, hydraulic turbine blades, or 3D printing filaments all have one or two dimensions much larger than the third one. Similarly, the natural world is also filled with examples of slender structures: tree branches and leaves, hairs, spider silk, or cellular membranes, etc. My research focuses on the mechanics of slender structures, and this Discovery Program more specifically concerns the morphogenesis and Fluid-Structure Interactions (FSI) of biological slender structures. Morphogenesis describes how biological cells grow and divide to shape organs and organism, i.e., how shape and structure originates. Mechanical forces play a central role in morphogenesis either as internal loads or external stimuli. One predominant source of external forces is FSI. It thus creates a feedback loop of shape and structure influencing FSI, and FSI affecting morphogenesis in return. Specifically, this Discovery Program addresses the following questions. How do seaweeds grow to achieve their variety of shapes? How does their hydrodynamic environment influence their growth? How do plants grow? Do they only inflate their cells like balloons under pressure or do they also swell their cell walls? How come trees bend under the wind to reduce their drag but do not flutter like flags? Does oscillating allow grasses to capture more wind-borne pollen? Similarly, does oscillating allow soft corals to capture more water current-borne food particles? My approach combines theoretical models, table-top experiments of idealised systems, and observations on natural systems obtained in a framework of tight collaboration with biologists. Over the long term, answering the questions above is crucial to optimise seaweed aquaculture, agriculture, forestry, and hydrology to maximise output and minimise our impact on the environment. The fundamental knowledge will serve as the base ingredients for models of wind damages to crops and forests, and water flow in vegetated canals and flooded land. This knowledge will prove ever more important in the context of changing climate and more frequent storms. Combining both applied industrial research and biomechanics into one lab brings in enormous benefits of synergy in terms of cross-breeding of ideas. Through biomimetic, the research in this discovery program will have an immediate impact on the development of self-cleaning hydrophobic surfaces, hierarchical 3D printed filaments with high surface area for tissue engineering, high toughness micro-structured fibers, or oscillation-enhanced heat exchangers for laminar flow conditions, etc.