Related Experiment Video
Updated: Dec 28, 2025

Fabrication, Operation and Flow Visualization in Surface-acoustic-wave-driven Acoustic-counterflow Microfluidics
Published on: August 27, 2013
Tritoroidal particle rings formation in open microfluidics induced by standing surface acoustic waves
Tengfei Zheng1,2, Chaohui Wang1,2, Chaoping Xu1,2
1State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, P.R. China.
Abstract:
In this paper, the particle movements in a sessile droplet induced by standing surface acoustic waves (SSAWs) are studied. Tritoroidal particle rings are formed under the interaction of acoustic field and electric field. The experimental results demonstrate that the electric field plays an important role in patterning nanoparticles. The electric field can define the droplet shape due to electrowetting. When the droplet approximates a hemisphere, the acoustic radiation force induced by SSAWs drives the particles to form tritoroidal particle rings. When the droplet approximates a convex plate, the drag force induced by acoustic steaming drives the particle to move. The results will be useful for better understanding the nanoparticle movements in a sessile droplet, which is important to explain the mechanism that SSAWs enhance reaction and crystallization in droplet.
Related Concept Videos
Steady, Laminar Flow in Circular Tubes
Steady, Laminar Flow Between Parallel Plates
Standing Waves in a Cavity
Toroids
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb points in...
Torque On A Current Loop In A Magnetic Field
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Surface Tension of Fluid
Surface tension varies...

