Toward total automation of microfluidics for extraterrestial in situ analysis

Despite multiple orbiter and landed missions to extraterrestrial bodies in the solar system, including Mars and Titan, we still know relatively little about the detailed chemical composition and quantity of organics and biomolecules in those bodies. For chemical analysis on astrobiologically relevant targets such as Mars, Europa, Titan, and Enceladus, instrumentation should be extremely sensitive and capable of analyzing a broad range of organic molecules. Microchip capillary electrophoresis (μCE) with laser-induced fluorescence (LIF) detection provides this required sensitivity and targets a wide range of relevant markers but, to date, has lacked the necessary degree of automation for spaceflight applications. Here we describe a fully integrated microfluidic device capable of performing automated end-to-end analyses of amino acids by μCE with LIF detection. The device integrates an array of pneumatically actuated valves and pumps for autonomous fluidic routing with an electrophoretic channel. Operation of the device, including manipulation of liquids for sample pretreatment and electrophoretic analysis, was performed exclusively via computer control. The device was validated by mixing of laboratory standards and labeling of amino acids with Pacific Blue succinimidyl ester followed by electrophoretic analysis. To our knowledge, this is the first demonstration of completely automated end-to-end μCE analyses on a single, fully integrated microfluidic device.