[SMaLS] Emergent mechanics in Earth-mediated soft systems

Speaker: Shravan Pradeep (Center for Soft and Living Matter Postdoc Fellow, University of Pennsylvania)

Title: Emergent mechanics in Earth-mediated soft systems

Abstract: Earth materials, much like living organisms, have evolved over millions of years, developing distinctive mechanical and transport properties. How does nature engineer soil with specific functions? What general principles govern the emergence of macroscopic soil properties, and how can they guide the development of new fundamental ideas in soft matter physics? My research addresses these questions by recasting soil as a hierarchical class of soft matter, revealing how microscopic interactions give rise to mesoscale structures and macroscopic mechanics. I will discuss two major themes that progressively incorporate greater complexity, both in the systems examined and the multiscale methods employed, to illustrate this framework. First, I will present a geo-inspired "Soft Earth" system, an idealized model soil, that exhibits an interaction-controlled rate-dependent plastic flow and brittle-to-ductile failure transitions. Second, I will describe a multiscale framework coupling flow, friction, and adhesion in natural muds to explain their unique gripping and lubrication behavior, properties famously harnessed by Major League Baseball in the "rubbing mud" used to prepare every game ball. Together, these studies illustrate how re-imagining soil as a class of complex soft matter can yield new fundamental understanding to unify yielding framework in soft particulate systems and generate simple design principles for valorizing Earth-mediated circular materials, with potential applications spanning climate-resilient soils, precision agriculture, and planetary terraforming.