The radiation force on a rigid sphere in standing surface acoustic waves

In this paper, the theory of acoustic radiation force exerted by standing surface acoustic waves (SSAWs) on a rigid sphere in ideal fluids is extended to account for the Rayleigh angle. The conventional theory used to calculate the radiation force acting on spheres in SSAWs is developed for plane standing waves (PSWs). PSWs exclude the dependence on the Rayleigh angle, causing significant limitations in the SSAW-based application settings. The radiation force on a cylinder in SSAWs is calculated based on which spherical structure is to be further considered. The Rayleigh angle effects can amplify the force of acoustic radiation in the direction normal to the piezoelectric substrate. In addition, the Rayleigh angle plays a notable role in both the magnitude and sign of the acoustic radiation force in the direction parallel to the substrate, which is significant for manipulating spherical particles in SSAWs. Thus, our formulas have great potential in the SSAW-based applications. Published by AlP Publishing.