Cavitation is the sudden, unstable expansion of a void or bubble within a liquid or solid subjected to a negative hydrostatic stress. Cavitation rheology is a field emerging from the development of a suite of materials characterization, damage quantification, and therapeutic techniques that exploit the physical principles of cavitation. Cavitation rheology is inherently complex and broad in scope with wide-ranging applications in the biology, chemistry, materials, and mechanics communities. This perspective aims to drive collaboration among these communities and guide discussion by defining a common core of highpriority goals while highlighting emerging opportunities in the field of cavitation rheology. A brief overview of the mechanics and dynamics of cavitation in soft matter is presented. This overview is followed by a discussion of the overarching goals of cavitation rheology and an overview of common experimental techniques. The larger unmet needs and challenges of cavitation in soft matter are then presented alongside specific opportunities for researchers from different disciplines to contribute to the field. soft solids | traumatic brain injury | TBI | rheology | bubble Cavitation is the sudden, unstable expansion of a void or bubble within a liquid or solid subjected to a negative hydrostatic stress. While predominantly studied in fluids, cavitation is also an origin of damage in soft materials, including biological tissues. Examples of cavitation in fluids and soft solids are shown in Fig. 1 A-C. As one key example, strong evidence suggests that cavitation occurs in the brain during sudden impacts, leading to traumatic brain injury (TBI) (3). Research on this life-impacting injury and its relation to cavitation has accelerated in recent years (4-8). A broader and deeper understanding of cavitation within soft matter is necessary to navigate the complex paths that lead to damage in the brain and other soft materials. Cavitation in fluids has been studied extensively since Rayleigh's (9) formulation in 1917, which predicted that the maximum pressure in a cavitating liquid is proportional to the far-field pressure and inversely proportional to the cavity size. As surface energy

Characterizing the high-strain-rate and high-strain mechanics of soft materials is critical to understanding the complex behavior of polymers and various dynamic injury mechanisms, including traumatic brain injury. However, their dynamic...