Characterizing interfacial energy and liquid-condensed / liquid-expanded domain morphology in two-dimensional systems

The National Science Foundation Division of Chemical, Bioengineering, Environmental, and Transport Systems awarded Augsburg University $307,710 on August 1, 2026, under the Engineering program (CFDA 47.041) to characterize interfacial energy and liquid-condensed/liquid-expanded domain morphology in two-dimensional lipid systems.

The project will develop and apply a non-perturbative fluorescence microscopy method to measure line tension at lipid phase boundaries and examine how lipid composition and additives such as cholesterol affect interfacial properties and monolayer pattern formation. Specific research aims include generalizing line tension measurements across phospholipid monolayers of varying composition, determining how linactants affect line tension and growth instabilities, and studying the growth of single liquid-condensed domains. Work will examine how phospholipid headgroup charge, chain length, and surfactant structure influence line tension and morphology. Results are intended to support rational design and fabrication of lipid interfaces for pharmaceutical drug delivery, biosensors, lab-on-a-chip devices, and other biological and materials applications. The project includes student researcher training and development of educational materials.

Performance occurs at Minneapolis, Minnesota through July 31, 2029. Augsburg University, a tax-exempt private nonprofit based in Minneapolis, will deliver the research and training activities.

Abstract

Lipids are FAT-like molecules that do not mix well with water. Lipids have many technological and industrial applications. For example, pharmaceutical companies use lipids for drug delivery applications. Food and personal care companies use lipids as non-toxic foaming agents and emulsifiers. Lipid systems can form complex patterns and shapes in two dimensions. This project will use a new method to measure the energy required to form a boundary between lipid phases in two dimensions. IT will also examine how lipid constituents affect pattern formation. The results may lead to new technologies for drug development and delivery, biosensors, and lab-on-a-chip devices. Results from this project also extend to other materials and interfaces, such as the inner lining of the lungs. Student researchers will be trained in valuable workforce-ready skills. Additional benefits will be educational materials developed during this project. Lipid monolayers at the air/water interface can coexist in the liquid-condensed (LC) and liquid-expanded (LE) phases. These phases form complex two-dimensional domains or stripe patterns due to competition between interfacial line tension and differences in dipole density between the two phases. This project will use a new non-perturbative method for measuring line tension from fluorescence microscopy images. The work will focus on three aims: generalizing LC/LE line tension measurements across phospholipid monolayers of varying composition; determining how linactants, such as cholesterol, affect line tension and growth instabilities; and studying the growth of single LC domains. The project will yield insights into how phospholipid headgroup charge, chain length, and surfactant structure affect line tension and monolayer morphology. The results will support the rational design and fabrication of lipid interfaces for biological and technological applications. The project will result in new curricular materials in image processing, data analysis, and general education. Undergraduate students will develop research skills as they address these scientific questions. The project will sustain a research collaboration between a primarily undergraduate institution and the university of minnesota. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are not planned for this award.