Optical Fibre Picorheology

Soft materials such as food biopolymer mixtures (eg fruit pastels) and blood clots are both viscoelastic and can thus both store and dissipate energy. Indeed this is vital to their correct functioning in industry and biology. We will build a new device to measure the viscoelasticity of tiny quantities (picolitre) of such materials. It will allow us to construct a picture of how blood clots are formed from ruptured arteries, since the device can be placed at a number of locations in the materials sampling their whole behaviour. The picorheometer functions at such high frequencies (-MHz) that the measurements can probe the internal dynamics of the molecules jiggling around in solution. This will allow us the build models connecting the molecular structure to how they flow when deformed. Blood clots are implicated in a series of medical conditions including hemophilia and strokes. The food industry now uses a large range of sophisticated ideas from theoretical physics to determine the shape and viscosity of foods. The picorheometer will allow foods to be examined dynamically, again allowing new structure/motion models to be built, which can subsequently be related to recipes used in their production.