The performance of many modern day methods of analysis (e.g., sensors and separations) is dictated by chemical and physical interactions at interfaces. This presentation describes three novel approaches to the creation of analytical methods and instrumentation based on different attributes of interfacial processes. The first approach entails the development and concept demonstration of a biochemical cassette for immunoassays. This strategy exploits the ability of atomic force microscopy to detect changes in the topology of an array of antigens immobilized on gold surfaces in a grid-like array that arise from specific binding with solution-based antibodies. The second approach involves the coupling of electrochemical methods and liquid chromatography. This technique, termed electrochemically modulated liquid chromatography, connects conductive stationary phases (e.g. porous graphitic carbon) as the working electrode in a LC column configured as an electrochemical cell. Alterations in the applied voltage then change the effective surface composition of the stationary phase, and therefore the extent of the retention of a vast array of analytes. The third approach explores the ability to construct a miniaturized fluid pump for use in chip-scale LC and flow injection analysis systems by using the changes in the shape of liquid mercury that arise from electrochemically-induced changes in its surface tension. The design, testing, and plans for miniaturization are described.