Universal RF-Powered Aqueous Extractor-on-a-Chip Instrument for Identification of Chemical Signatures of Life on Mars

The prospect of finding chemical signatures of present or past life on Mars is one of the important drivers behind Mars exploration program (MEP). One of the technical challenges facing MEP is the lack of compact and universal sample processing technology that enables the cataloging of organic molecules in Martian crustal materials. In the past year, we have been developing a super-compact, lightweight and low power-consumption microfluidic extractor-on-a-chip (μEX) instrument that will address this challenge for in situ Mars exploration missions and Mars Sample Return sample analysis. The core operational principle of μEX is based on a unique property of water - the ability to change its permittivity (i.e., dielectric constant) as a function of frequency to match the dielectric constants of organic solvents. In our instrument, the dielectric constant of water decreases when 180 GHz RF radiation interacts with translational modes in a solution by disrupting orientation of the water molecules’ individual molecular dipoles. Since “like dissolves like”, μEX can then extract biomarkers from soil samples by simply applying 180 GHz radiation to water, without the use of any other chemicals. Consequently, target biomarkers that are characterized by very different properties (e.g., size, charge, volatility, polarity, etc.), and which are typically only soluble in organic solvents, can now be easily extractable from the solid matrices and soluble in water. Here we present our research results, which include characterization of μEX operation and data on organics extracted from Mars-analog soil samples.