The potential discovery of extraterrestrial biosignatures within our solar system would represent a transformative milestone, reshaping our understanding of life and our place in the universe. Such a finding would imply that life is not unique to Earth, but is potentially a widespread phenomenon. It would expand our biological knowledge by exploring alternative biochemistries, the evolution of biochemical pathways, and revealing how life adapts to extreme environments. Moreover, it would guide the direction of future space exploration, refining the methodologies used to detect extraterrestrial biosignatures and informing the selection of mission targets.
This dissertation contributes to these goals by advancing microfluidic technologies for the most sensitive detection of potential biosignatures in the solar system. Centered on the development, optimization, and application of the Microfluidic Organic Analyzer (MOA), this work introduces an advanced instrument in a compact form, tailored for space-based high-resolution, high-sensitivity chemical analyses. Integrating a Programmable Microfluidic Analyzer (PMA) with a microfabricated glass Capillary Electrophoresis (CE) wafer, the MOA is crafted in a flight-capable, low-mass format. This innovative design enables the precise and sensitive detection of organic biomarkers through laser-induced fluorescence, providing the necessary sensitivity and resolution for a meaningful analysis of habitability and the potential presence of biosignatures, for example, on icy moons such as Europa and Enceladus, as well as on Mars.
Key advancements developed here include the refinement of microfabrication techniques for glass microfluidic and CE devices, aligning them with rigorous industrial standards and quality controls required for space flight instrumentation. To achieve high levels of sensitivity and resolution necessary for fluorescence analysis in capillary electrophoresis, excellent quality glass CE wafers need to be designed and fabricated. Stringent quality control protocols have been established to ensure that researchers can reliably achieve the highest precision in fabricating these glass microdevices, a crucial factor in space instrumentation development. Moreover, this dissertation details significant enhancements to the MOA’s fluorescent labeling and detection methodologies, pivotal for identifying trace biosignatures in extraterrestrial environments. The operational readiness of the MOA for space missions has been validated through testing in micro- and hyper-gravity conditions via Zero-G parabolic flights. These tests, along with developed automated protocols on the PMA, facilitate remote, autonomous operation, underscoring the MOA’s ability to perform under the challenging conditions encountered during space exploration.
A variety of Earth-based analog sites and samples have been examined to establish a reference framework for interpreting biomarkers detected on icy worlds. By analyzing organic biosignatures in challenging terrestrial environments, such as Antarctic ice cores and geothermal hot springs, this work provides a comparative baseline for extraterrestrial biosignature detection by identifying the identities and concentrations of potential biosignatures that must be detected. The necessity for highly sensitive detection technologies, capable of detecting low picomolar concentrations, is emphasized to enable meaningful measurements even on Earth, where life is abundant in the ecosystem. This level of sensitivity is crucial because extraterrestrial sites that can be examined, much like the most challenging and biosignature-poor sites on Earth, may exhibit only trace amounts of biosignatures. Accordingly, the MOA is meticulously engineered to detect even the subtlest signs of life, aligning with the nuanced complexities of our current understanding of life’s potential distribution across the cosmos.
This research enhances the technological readiness of microfluidic systems for planetary exploration, supporting the search for life beyond Earth and potentially changing our understanding of life and biochemical evolution across the cosmos.
