National Science Foundation
Studies of interfacial forces will provide information about field-induced changes in the charge distribution and forces at solid/liquid and fluid interfaces that are important in electrowetting.
As device dimensions shrink into the nanometer range, interfacial forces become increasingly important. At the same time, traditional continuum theories of interfacial forces become inadequate, and fundamentally new phenomena appear. A combination of experimental and theoretical tools will be used to determine the limits of traditional theories, identify new interfacial phenomena, develop general models for interfacial forces at the nanometer scale, and explore processes that may enable new active nanodevices. New approaches for making measurements at smaller scales and performing simulations at larger scales will allow experiments and simulations to consider the same phenomena on scales from 10 to 100 nm. Measurements and simulations of capillary forces on chemically modulated nanowires and 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 solid/liquid and fluid interfaces that are important in electrowetting. Prototypes for active nanodevices such as bistable switches and actuators will be evaluated in the above geometries, extending microfluidic mechanisms to smaller scales and exploring new driving forces that become significant at nanometer scales.