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Sample Processor for Life on Icy Worlds (SPLIce): Design and Test ResultsWe report the design, development, and testing of the Sample Processor for Life on Icy Worlds (SPLIce) system, a microfluidic sample processor to enable autonomous detection of signatures of life and measurements of habitability parameters in Ocean Worlds. This monolithic fluid processing-and-handling system (Figure 1; mass 0.5 kg) retrieves a 50-L-volume sample and prepares it to supply a suite of detection instruments, each with unique preparation needs. SPLIce has potential applications in orbiter missions that sample ocean plumes, such as found in Saturns icy moon Enceladus, or landed missions on the surface of icy satellites, such as Jupiters moon Europa. Answering the question Are we alone in the universe? is captivating and exceptionally challenging. Even general criteria that define life very broadly include a significant role for water [1,2]. Searches for extinct or extant life therefore prioritize locations of abundant water whether in ancient (Mars), or present (Europa and Enceladus) times. Only two previous planetary missions had onboard fluid processing: the Viking Biology Experiments [3] and Phoenixs Wet Chemistry Laboratory (WCL) [4]. SPLIce differs crucially from those systems, including its capability to process and distribute L-volume samples and the integration autonomous control of a wide range of fluidic functions, including: 1) retrieval of fluid samples from an evacuated sample chamber; 2) onboard multi-year storage of dehydrated reagents; 3) integrated pressure, pH, and conductivity measurement; 4) filtration and retention of insoluble particles for microscopy; 5) dilution or vacuum-driven concentration of samples to accommodate instrument working ranges; 6) removal of gas bubbles from sample aliquots; 7) unidirectional flow (check valves); 8) active flow-path selection (solenoid-actuated valves); 9) metered pumping in 100 nL volume increments. The SPLIce manifold, made of three thermally fused layers of precision-machined cyclo-olefin polymer, supports all fluidic components (Figure 1) and integrated microchannels (125 x 250 m). Fluid is pumped by a stepper-motor-driven pump (Lee Co.). The functionality of the integrated MEMS pressure sensor (Honeywell) and passive check valves (Figure 2) were tested in conjunction with our newly designed integral bubble traps (Figure 3) and hydrophobic membrane-based concentrator (Figure 4). The concentrator (initially tested as a standalone component) demonstrated 5-fold vacuum-evaporative concentration. Polyethylene fused bead beds (PEFBBs; 50 porosity) store drylyophilized buffers, calibrants, and fluorescent dyes, and also promote mixing of sample with calibrant, dye, or H2O. Software-controlled automated tests demonstrated successful 1) fluid delivery to each component 2) valve and pump synchronization 3) sample aliquot delivery to instrument interface ports, and 4) rehydration of vacuum-dried fluorescent dye. In Figure 5, fluorescein on PEFBBs was rehydrated for 15 min using a pump-delivered water aliquot; it is displaced as H2O enters the bottom of the channel and pushes the dye into a check valve. Ultimately, SPLIce will fluorescently label amino acids in the sample for microchip-based electrophoretic (MCE) chiral separation and detection to seek and quantify key organic bio-signatures [5]; it will also deliver sample to a microfluidic version of WCL (mWCL) to measure soluble ions and redox-active species.
Document ID
20170011062
Document Type
Conference Paper
Authors
Chinn, Tori N. (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
Lee, Anthony K. (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
Boone, Travis D. (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
Tan, Ming X. (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
Chin, Matthew M. (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
McCutcheon, Griffin C. (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
Horne, Mera F. (Universities Space Research Association Moffett Field, CA, United States)
Padgen, Michael R. (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
Blaich, Justin T. (Millennium Engineering and Integration Co. Moffett Field, CA, United States)
Forgione, Joshua B. (NASA Ames Research Center Moffett Field, CA, United States)
Gentry, Diana (NASA Ames Research Center Moffett Field, CA, United States)
Zell, Peter T. (NASA Ames Research Center Moffett Field, CA, United States)
Bywaters, Kathryn F. (Search for Extraterrestrial Intelligence Inst. Mountain View, CA, United States)
Kelly, Erin T. (Search for Extraterrestrial Intelligence Inst. Mountain View, CA, United States)
Davila, Alfonso F. (NASA Ames Research Center Moffett Field, CA, United States)
Ricco, Antonio J. (IPA-ARC Moffett Field, CA, United States)
Date Acquired
November 13, 2017
Publication Date
October 22, 2017
Subject Category
Lunar and Planetary Science and Exploration
Astronomy
Report/Patent Number
ARC-E-DAA-TN44735
Meeting Information
International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2017)(Savannah, GA)
Funding Number(s)
CONTRACT_GRANT: NNX15AP13A
CONTRACT_GRANT: SAA2401923
OTHER: 20001.04.04C0.00.265000
CONTRACT_GRANT: NNA13AC87C
CONTRACT_GRANT: NNH15CO48B
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
Life detection
Icy worlds
SPLIce
Enceladus

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