Microfluidic Inorganic Conductivity detector for Europa (MicroICE) using capacitive coupling

Assessing the habitability of astrobiologically exciting worlds like Europa require analyses that are only available through in-situ missions. We have developed a science payload to fit within a stringent volume, mass, and power usage envelope, the Ice Shell Impact Penetrator (IceShIP) with state-of-the-art analytical instrumentation for detecting low concentration organics, the Icy Moon Penetrator Organic Analyzer (IMPOA), capable of sustaining >50 k-g impact load. This work reports the integration of MicroICE, a capacitively coupled contactless conductivity detector (C
⁴
D), for quantifying low concentration inorganics. We have used a fast, highly reproducible, resource-efficient technique resulting in a 95±11 micron thick PDMS layer with simple fabrication for easy technology transfer for flight applications. The LODs were 78±6 µM NaCl, 29±18 µM MgSO
4
, 28±8 µM Na
2
SO
4
, 72±14 µM KCl and exceeded the NASA Europa Lander SDT report target LOD by four orders of magnitude. Device performance for three identical devices had no statistically significant differences and retained consistent performance even after a 30-day benchtop storage. Robustness, repeatability, and reproducibility are critical for high acceleration space-flight missions and this work presents a technique that satisfies these key aspects with performance exceeding that requested by NASA in a small mass, energy-efficient design.