Acoustic microstreaming near a plane wall due to a pulsating free or coated bubble: velocity, vorticity and closed streamlines

Abstract

Acoustic microstreaming due to an oscillating microbubble is analytically investigated to obtain the circular streaming motion adjacent to a nearby wall. Classical theory due to Nyborg is carefully derived in the radial coordinates. The theory is used to obtain the flow field and the vortical motion caused by the microbubble motion. The length of the vertices are decreasing when the microbubble is excited at distances close to the rigid wall, while the maximum shear stress is increasing.

Ultrasound and Microbubbles for Targeted Drug Delivery to the Lung Endothelium in ARDS: Cellular Mechanisms and Therapeutic Opportunities

“…Using a combination of particle image velocimetry (PIV) and theoretical analysis, other researchers have shown that the shear stresses induced by acoustic microstreaming flows around microbubbles are significantly higher (~19 Pa) than the shear stresses induced by normal blood flow (~0.5-2 Pa), resulting in sonoporation [102]. These and several other theoretical and experimental studies showed that acoustic microstreaming may be a major mechanism of sonoporation [105][106][107]. Furthermore, microstreaming flow pattern is strongly dependent on the driving ultrasound frequency, microbubble size, pressure amplitude, properties of surrounding media as well as oscillation mode of microbubbles, which might explain why sonoporation and intracellular delivery of molecules are strongly affected by these parameters, as noted in several other studies [102,[108][109][110].…”

Advances in Micromanipulation Actuated by Vibration-Induced Acoustic Waves and Streaming Flow

“…With flexibility and scalability similar to microrobots, their cost is much lower. Microbubbles have complex fluid and vibration models [33], especially for the Bjerknes force generated by the interaction of multiple bubbles [34,35], and the control method means that it is also one of the objects of micromanipulation [36]. The study of microbubbles has its own field.…”

“…Therefore, particles can still be dynamically analyzed by the method described above. Hydrodynamics is highly nonlinear, and studies related to micromanipulation are numerous and complex [33,47,48]. Here, we summarize the simple mechanical principles involved in streaming flow rather than precise numerical solutions.…”

“…In particular, several bubbles that are close to each other and in a vibrating state can produce more complex mechanical phenomena that can be partially solved by applying Bjerknes' circulation theorem. Some related studies were published about the stream around multiple bubbles, such Mobadersany et al [33], and the influence of stream on bubbles, such as Combriat et al [35]. The microrobot system proposed by Ren et al showed the potential of Bjerknes force in the field of acoustic manipulation.…”

Echogenic exosomes as ultrasound contrast agents

“…[37][38][39][40][41] UCA oscillations also cause acoustic microstreaming ows surrounding the microbubble leading to enhanced mixing and shear stress experienced by nearby cell membranes. 31,42 The shear stress is believed to increase membrane permeability or excite mechanosensitive ion channels, potentially allowing for therapeutic drug delivery to the cells. 43,44 However, UCAs are restricted to the vascular system as they are too large to permeate outside of the blood vessels.…”