Experimental and numerical investigation of dynamic cavitation in agarose gel as a soft tissue simulant

Abstract

In recent years, soft gels, including agarose, have been widely used to mimic soft biological tissues. Hence, such materials’ transient dynamic response has become increasingly relevant. When gels are subjected to an impact, the typical mechanical response is associated with the cavitation of bubbles.This study presents experimental and numerical investigations on the dynamic behavior of impact-induced cavitation in agarose gels. The drop tower test was used for the experiments, and agarose samples with three different concentrations similar to soft brain tissue were tested. The acceleration causing the bubble cavitation and the correlated bubble sizes were determined. Such quantitative measurements can be utilized to evaluate brain tissue injuries.In parallel, we present finite element simulations of the drop tower experiment. We model the complete test setup to validate the measurements and derive the relevant pressure fields with simplified models. The numerical solutions are shown to be in excellent agreement with the experimental results of bubble cavitation, enabling substantial simplifications in further investigations of soft tissue under dynamic loading.Our study gives insight into the mechanisms of bubble cavitation in soft tissue. Combined with the numerical simulation, it estimates how impact and pressure waves act and, for example, which areas of the head may be affected by cavitation that induces brain injuries.