This proposal was received in response to the Active Nanostructures and Nanosystems initiative, NSF 06-595, category NIRT. As device dimensions shrink towards molecular scales, interfacial forces become increasingly important and traditional theories that smear out atomic structure become inadequate. The research team will combine new experimental and theoretical methods to determine the limits of traditional theories, identify new interfacial phenomena, develop general models for interfacial forces at the nanometer scale, and explore new strategies for active nanodevices. Measurements and simulations of capillary forces on chemically modulated nanowires and on menisci confined in nanometer gaps will probe changes with length scale in surface tension, static and dynamic contact angles, contact angle hysteresis, and capillary actuation by light and electric fields. Studies of interfacial forces will provide information about field-induced changes in the charge distribution and forces at interfaces that are important in electrowetting.
The proposed research will improve our fundamental understanding of fluid flow, capillary phenomena and actuation at the nanometer scale. The results will be directly relevant to the design and optimization of active nanodevices, and aid understanding of unwanted adhesion in micro-electro-mechanical systems and of transport of ground water and oil in small pores. Students will receive a broad interdisciplinary training that will enable them to become leaders in the rapidly developing field of nanotechnology. Multiscale modeling software developed as part of the research will be made publicly available through a collaboration with Sandia National Laboratories. Outreach will be coordinated with local programs, including the Center for Educational Outreach and the Materials Research Science and Engineering Center on nanostructured materials, the annual Physics Fair, the Center for Talented Youth, and the Youth for Astronomy and Engineering Program.
