Figure 5.

Normalized radii of a 1 μm lipid-coated bubble as a function of time (a) without (model II) and (b) with (model IV) considering the inter-bubble interactions with a large lipid-coated bubble (R₂₀ = 5 μm), and (c) the corresponding maximum expansion ratios at different shell elasticities, while (d–f) represent those at different shell viscosities. The amplitude of applied ultrasound is 400 kPa, and the inter-bubble distance is 20 μm.