Modeling and Analysis of the Two-Dimensional Axisymmetric Acoustofluidic Fields in the Probe-Type and Substrate-Type Ultrasonic Micro/Nano Manipulation Systems

Abstract

The probe-type and substrate-type ultrasonic micro/nano manipulation systems have proven to be two kinds of powerful tools for manipulating micro/nanoscale materials. Numerical simulations of acoustofluidic fields in these two kinds of systems can not only be used to explain and analyze the physical mechanisms of experimental phenomena, but also provide guidelines for optimization of device parameters and working conditions. However, in-depth quantitative study and analysis of acoustofluidic fields in the two ultrasonic micro/nano manipulation systems have scarcely been reported. In this paper, based on the finite element method (FEM), we numerically investigated the two-dimensional (2D) axisymmetric acoustofluidic fields in the probe-type and substrate-type ultrasonic micro/nano manipulation systems by the perturbation method (PM) and Reynolds stress method (RSM), respectively. Through comparing the simulation results computed by the two methods and the experimental verifications, the feasibility and reasonability of the two methods in simulating the acoustofluidic fields in these two ultrasonic micro/nano manipulation systems have been validated. Moreover, the effects of device parameters and working conditions on the acoustofluidic fields are clarified by the simulation results and qualitatively verified by the experiments.

Sophisticated acoustofluidic patterns generated in quasi-Sierpiński-carpet shaped chambers with heterogeneous radiation surface distributions

“…The left side of equation (2) indicates the inertial force per unit volume acting on the fluid with the two terms in the parentheses being the local acceleration and convective acceleration, respectively, while the right side denotes the stress variations including the pressure gradient and the viscous forces. Other forces, such as gravity force and buoyancy force, are not taken into consideration due to the reason that they are approximately negligible compared with the aforementioned driving forces [33].…”

Ultrasonic trapping and collection of airborne particulate matter enabled by multiple acoustic streaming vortices

“…As is well known that when an object is in an acoustic field, it may experience the acoustic radiation force [37][38][39][40][41] and the acoustic streaming-induced drag force [27,33,42]. The acoustic radiation force on a single airborne particulate matter in the acoustic field is: where R p is the radius of the particulate matter, ρ p is the density of the particulate matter, and c p is the sound speed in the particulate matter [37].…”