Buckling resistance of solid shell bubbles under ultrasound

Area of Science:

• Acoustic physics
• Materials science
• Biomedical engineering

Background:

• Contrast agent bubbles are crucial in medical ultrasound imaging.
• Understanding bubble shell behavior under acoustic stress is key for optimizing imaging.
• Solid shell bubbles exhibit distinct mechanical properties compared to lipid monolayer bubbles.

Purpose of the Study:

• To investigate the volume oscillating behavior of thin solid shell contrast agent bubbles under increasing acoustic power.
• To model the abrupt buckling transition observed in solid shell bubbles.
• To establish a relationship between acoustic pressure and bubble shell mechanics.

Main Methods:

• Numerical simulations incorporating shell bending modulus to determine critical buckling pressure and post-buckling shape.
• Experimental validation of simulation findings.
• Development of a model based on effective surface tension.

Main Results:

• Solid shell bubbles resist compression, leading to an abrupt buckling transition.
• Simulations predicted the appearance of a finite number of wrinkles post-buckling.
• The developed model, using buckling tension and rupture shell tension, favorably compared to experimental data.

Conclusions:

• The buckling tension directly estimates the acoustic pressure threshold for bubble buckling.
• The study provides a robust model for predicting solid shell bubble behavior under acoustic load.
• Findings enhance the understanding and application of solid shell contrast agents in medical imaging.