MMEAW: Modelling the MEchanics of Animal Whiskers

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MMEAW is a multidisciplinary project, lying at the interface between structural engineering, robotics and comparative animal physiology. It aims to extend our understanding and knowledge of how whiskers are adapted to their function and apply that understanding to applications in engineering. MMEAW builds on previous research in this field, for example the EPSRC funded Whiskerbot project (EPSRC ref: GR/S19639/01). The aims of MMEAW are as follows:1) Understanding how animals exploit a range of whisker morphological parameters such as taper, curvature, twist, stiffness, anisotropy and weight, to their advantage.2) Determining critical values of taper, twist, curvature and relationships between them e.g., ratio of weight to length (curliness), which lead to qualitative change in vibrissae mechanics. Thereby identify criteria for optimal performance.3) Establishing a rational scheme for classifying vibrissae.MMEAW involves two key activities. First, by taking measurements of the shape and form of animal whiskers, it will build a data base of detailed information on whisker morphologies. Working with museums, we shall gather data on a range of species - from small rodents, to large mammals and to birds. The information we are interested in includes details of the length, curvature, taper, weight, tortuosity (i.e., out of plane curvature), and cross sectional properties, such as shape, diameter and stiffness. We also want to know details of how and where each whisker connects to the animal's face, including the angle and orientation of the whisker. All that information will be stored in a data base. Since no such data base exists anywhere, it will be made available to museums internationally, where it can be aggrandized. The process of gathering data on vibrissae will last one year.The second major activity involves the formulation of mathematical models, using the data gathered on vibrissae shape and form, and applying mechanics principles to analyse what happens to a whisker when its tip is disturbed e.g., when it brushes against different surfaces, is pressed in by a force, passes through a liquid (otters and seals) and undergoes the 'whisking motions' observed in some species (rats). MMEAW will use advanced modelling methods, based on the Cosserat Theory of rods, i.e., a rigorous mathematical theory of long slender structures. That approach will enable MMEAW to model the effects of different curvatures, tapers, tortuosity etc., within a unified and rational scheme, one that provides detailed information on the loads transmitted from the tip of the whisker to the base. The modelling and analysis will be complemented by field work (observations of animals) carried out by a member of the team with extensive specialist experience. Indeed, MMEAW involves the collaboration of a multidisciplinary team with strong track records in elastic rod theory, engineering and animal comparative physiology.By formulating a well posed mathematical problem, MMEAW will be able to identify optimal conditions for vibrissae and extend the analysis to embrace extreme loadings and deflections, thereby offering a global perspective on how different vibrissae morphologies affect performance. That information can be used by robotics engineers and structural engineers to implement optimal designs for flexible robotic arms and antennae, indeed it carries across to any engineer developing technology that involves long slender flexible structures; whether a robot arm, a building structure (beam, column, strut), a cable buoy system, a space tether, or a medical stent.