title: Proof of principle study of ultrasonic particle manipulation by a circular array device.
abstract: A feasibility study of a circular ultrasonic array device for acoustic particle manipulation is presented. A general approach based on Green's function is developed to analyse the underlying properties of a circular acoustic array. It allows the size of a controllable device area as a function of the number of array elements to be established and the array excitation required to produce a desired field distribution to be determined. A set of quantitative parameters characterizing the complexity of the pressure landscape is suggested, and relation to the number of array elements is found. Next, a finite-element model of a physically realizable circular piezo-acoustic array device is employed to demonstrate that the trapping capability can be achieved in practice.
authors.affiliation: Department of Mechanical Engineering ,  University of Bristol ,  Bristol BS8 1TR, UK.
authors.forename: Alon
authors.initials: A
authors.lastname: Grinenko
authors.forename: Paul D
authors.initials: PD
authors.lastname: Wilcox
authors.forename: Charles R P
authors.initials: CR
authors.lastname: Courtney
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Drinkwater