Driven by climate change, population growth, development, urbanization, and other factors, water crises represent one of the greatest global risks in the coming decades. Advances in materials represent a powerful tool to address many of these challenges. Understanding—and ultimately controlling—interfaces between materials and water are pivotal. In this presentation, Dr. Darling will lay out the challenges and present several examples of work in his group based on materials engineering strategies for addressing applications in water. In each instance, manipulation of interfacial properties provides novel functionality, ranging from selective transport to energy transduction to pollution mitigation.