Dry Eye Disease affects over thirty million Americans and imposes an annual economic burden exceeding $55 billion in healthcare costs and lost productivity. Despite its clinical importance, the fundamental principles connecting the molecular composition of this lipid layer to its mechanical performance remain poorly understood. Most current treatments address symptoms rather than the underlying causes of film instability. This research project will identify the design rules that govern how tear film lipid composition controls stability, lubrication, and resistance to mechanical failure. The findings will provide a scientific foundation for developing targeted therapies for Dry Eye Disease. They will also guide the creation of bio-inspired lubricating materials for medical technologies such as long-wear contact lenses, ocular implants, and artificial joint systems, contributing to United States leadership in biotechnology. The project includes a hands-on outreach module, The Amazing Engineering of Your Eye, designed to introduce kindergarten through K12 students to core concepts in biomechanics and biomedical engineering. University students will receive training in advanced biophysical measurement methods, building a skilled and interdisciplinary workforce for the biotechnology sector. This research project seeks to establish a quantitative, mechanism-based framework linking the molecular architecture of the tear film lipid layer to its interfacial biomechanical and tribological performance. Although the biochemical composition of the tear film has been extensively cataloged, the causal relationships between nonpolar lipid attributes and the resulting mechanical stability, adhesion, and frictional response remain unresolved. Three coordinated research objectives address this gap through the lens of interfacial biomechanics and mechanobiology. Objective 1 will determine how structural features of major nonpolar lipid classes, wax esters, cholesterol esters, and tr