(4fi) Engineering Earth-Mediated Sustainable Soft Matter for Energy, Environment, and Space Exploration Applications

Bold approaches are required to address the pressing global challenges posed by the increasing population, finite natural resources, and the effects of climate change. General solutions include decarbonizing our economies, promoting sustainable materials, and space exploration for resource extraction. Motivated by the renewed interest in using sustainable geomaterials to help meet the UN Sustainable Development Goals for resilient infrastructure and climate action, my lab will use materials geomimicry to address these challenges. This innovative approach investigates the structure-property relationships of natural geomaterials, to architect novel class of sustainable matter that mimic their structure, resilience, and multifuntionality. Earth-based sustainable materials are akin to living matter in two ways: (1) they are naturally designed multifunctional structures; and (2) they are “self-learning” materials that are mechanically resilient to the barrage of environmental conditions under which they evolved. Geomaterials can sustain self-stress and possess unique transport properties due to the optimized interparticle interactions from a mixture of cohesive agents, natural stabilizers, geo- and biopolymers, frictional particles, and adequate moisture distribution. This hierarchical design of these “soft earth” structures aid in functions, such as, groundwater retention, carbon storage, and landscape stability. Unlocking the bottom-up design rules by probing structure-mechanics relationships at relevant length scales will unlock potential designs in engineering sustainable multiphase soft materials. Towards this central goal, the initial work in my lab will be focused in the following research areas:

• Designing sustainable soft earth materials with desired rheo-tribological properties: lubrication, adhesion, and friction.
• Engineering model systems for precise spatiotemporal characterization of material mechanics to train structure-property relationship models using physics-informed machine learning.
• Coupling non-linear dynamics and material rheology towards developing advance manufacturing protocols for 3D printing multiphase soft earth-mediated materials.

My group will leverage collaborations with soft matter simulationists, theorists, geochemists, and data science researchers in advancing these research goals.

Prior Research

My research has focused on understanding the effects of surface anisotropy and multiscale interactions on the flow properties of model dense suspensions and natural geomaterials. During my doctoral research, I explored colloidal surface anisotropy as a powerful method for engineering flow behavior in dense suspensions. By combining macro-scale rheology with in-situ microstructural characterization, I developed scaling theories that can be applied to a broad class of materials. Currently, my postdoctoral work is focused on understanding the multiphysics coupling of flow and frictional properties in soft earth materials. Our work explained the rheology of non-inertial geophysical flows using the framework established for dense suspensions and colloidal gels. We have applied our understanding of rheology in multiphase natural complex fluids to predict the hazard potentials associated with real-life mudslide data. In our most recent work, we explored the mechanical origins of baseball’s “Magic Mud” as a sustainable material with optimal rubbing and gripping properties. We uncovered that the baseball mud has an ideal composition of cohesive constituents and water to uniformly coat baseballs with a mildly adhesive residue, along with angular frictional grains that enhance friction.

Teaching Experience & Interests

Philosophy: Educating and mentoring next generation is central to my vision as an academic. My primary goal will be to cultivate positive learning and research environments where every student and trainee, regardless of their background, can thrive and achieve their full potential. I believe that the future of STEM education will focus on teaching philosophies that embrace equitable, learner-centered environments connecting real-life problems from the students’ communities. To realize this, the current one-size-fits-all approach should be amended for a more inclusive one.

Experience: I have nine semesters of teaching experience, both as a teaching assistant and guest lecturer, across chemical and mechanical engineering departments, spanning courses both at the undergraduate and graduate-level. During my doctoral and postdoctoral work, I engaged in diverse teaching environments, including classrooms and laboratories, with class sizes ranging from 20 to 180 students. A significant milestone in my teaching journey was obtaining Teaching and Communications Certificate through the NC State Graduate School. This program provided formal training in essential areas such as classroom communication strategies, effective structuring of course contents, engaging with a diverse student body, and developing a teaching portfolio.

Interests: While I am able to teach fundamental chemical engineering courses, I am especially interested in teaching transport phenomena and thermodynamics-related courses. Additionally, I would like to introduce a new interdisciplinary graduate elective course focused on mechanics of soft materials.

Honors and Awards (Selected)

• Penn Center for Soft and Living Matter Postdoctoral Fellowship (2024)
• APS Forum for Early Career Scientists Mini Grant (2024)
• APS Division of Soft Matter Future Investigator Travel Award (2023)
• ACS Colloids and Surface Science Division LaMer Award Finalist (2023)
• NC State James Farrell Outstanding PhD Student Award (2022)
• ACS Colloids and Surface Science Division Langmuir Graduate Award Finalist (2021)

Journal Publications (Selected)

• Shravan Pradeep, Paulo. E. Arratia, Douglas. J. Jerolmack, “Origins of complexity in Soft Earth suspensions”, Nature Communications (2024).
• Robert Kostynick*, Hadis Matinpour*, Shravan Pradeep*, Sarah Haber, Alban Sauret, Eckart Meiburg, Paulo E. Arratia, Douglas J. Jerolmack, “ Rheology of debris-flow materials is controlled by the distance from jamming”, PNAS (2022). *Equal contribution
• Shravan Pradeep, Alan Wessel, Lilian C. Hsiao, “Hydrodynamic origin for the suspension viscoelasticity of rough colloids”, Journal of Rheology (2022).
• Shravan Pradeep, Mohammad Nabizadeh, Alan R. Jacob, Safa Jamali, Lilian C. Hsiao, “Jamming distance dictates colloidal shear thickening”, Physical Review Letters (2021).
• Shravan Pradeep, Lilian C. Hsiao, “Contact criterion for suspensions of smooth and rough colloids”, Soft Matter (2020).