Investigation of acoustic radiation forces on micro-particles and biological cells in ultrasonic particle manipulation Seminar

Radiation force is a net force acting on a particle produced by difference of compression and expansion behaviour of fluids in an ultrasonic field. This force moves the dense objects towards the region of low pressure region. It can be used to trap, separate, agglomerate, levitate, filter and mix particles in a host fluid. To apply this technique safely and efficiently we need to predict the radiation force. The objective of my work is to characterise biological cells to better predict the radiation forces on them and how this can be applied to bio-medical advancement. Previous analytical solutions to calculate the acoustic radiation force for particles were limited to simple geometries and numerical solutions were restricted to particle and field representations, as well as being computationally demanding. To overcome these limitations an efficient and flexible numerical finite element (FE) model is developed to investigate acoustic radiation forces on a single particle of arbitrary size, shape, elasticity, and composition and material properties in a wide variety of stationary ultrasonic fields. The model compares well with analytical solutions and suggested useful results on shape dependency and the effects of shear waves in ultrasonic particle manipulation. The efficiency of the algorithm allows a significant volume of parameter space to be investigated within sensible time frames. The initial results are presented for the forces on inhomogeneous particles for example cell with a nucleus inside. The recent progress of the model including the viscosity is also discussed.