Inertial Interface Cavitation Creates Complex, Flow-Like Structures Within a Soft Solid

Abstract Background Inertial cavitation near soft material interfaces generates highly asymmetric bubble dynamics, intense stress localization, and complex fluid–structure interactions. However, the subsurface deformation fields within soft solids remain poorly resolved due to limitations in ultrafast, full-field measurement techniques. Objective This study aims to quantify the spatiotemporal deformation of soft hydrogels during laser-induced inertial cavitation near a gel–water interface. Methods We integrate single-pulse laser-induced inertial cavitation, an embedded internal Digital Image Correlation (DIC) speckle patterning method, and DIC to resolve in situ , full-field subsurface kinematics at 1–2 million frames per second. Results Among all the tested different non-dimensional stand-off distances, four distinct cavitation–interface interaction regimes are identified, spanning symmetric bulk-like oscillations to strongly asymmetric collapses accompanied by interface indentation, jet reversal, and bubble penetration. Full-field measurements reveal stagnation points, vortex-like deformation patterns, and large localized strains that depend on the non-dimensional bubble stand-off distance. Conclusions This work establishes an experimental framework for quantifying inertial cavitation dynamics near a compliant gel–water interface. Using ultrafast imaging and DIC, we captured full-field deformation, strain localization, and jet formation across a wide range of stand-off distances near gel–water interfaces.