As a geoscientist, I investigate the properties of diverse geomaterials in the Earth's subsurface, including rocks, minerals, soils, sediments, faults, and other porous or fractured media. My research is distinguished by clay across multiple length scales, spanning over 12 orders of magnitude—from nanometers to kilometers. I examine clay-water interactions at the atomic level, clay microstructure and dynamics at the microscale, the coupled physics of clay-rich geomaterials at the continuum scale, the influence of clay on geomaterial behavior at the laboratory scale, and its role in geofluid transport—including carbon dioxide, water, and hydrocarbons—at regional scales. This broad spectrum of investigation allows me to address important questions in sustainable geotechnics including (1) waste containment (bentonite barriers and clay liners), (2) clay-based geopolymers, (3) geotechnical behavior of clay soils, (4) contaminant sequestration, (5) clay sediment transport, (6) carbon geologic storage, and (7) geo-energy applications.