For the last decade, most applications of microfluidics for “lab-on-a-chip” (LOC) technology have focused on the successful transfer of established technologies from conventional lab-bench methodologies to a chip-based format. Because of the unique environments offered within microfluidic networks, a variety of integration processes can be performed in a continuous format, on one platform. The Lab-on-a-Chip Application Development (LOCAD) team at NASA’s Marshall Space Flight Center is utilizing LOC to support technology development specifically for Exploration. This paper will describe the design and operation of an integrated micro-channel/microarray configuration. Specifically, the filling processes of a liquid inside a circular chamber hosting the micro-array, subjected to a specific inlet pumping velocity at various geometrical and/or operational parameters will be examined. Numerical simulations are performed for the movement of a liquid-gas two-phase flow inside the microchannel and the circular disk-shaped well. The numerical simulations were conducted using the free surface Volume of Fluid (VOF) method which allows for the interface between two immiscible fluids to be simulated while incorporating the effects of surface tension. The results are presented in terms of the movement of the gas-liquid interface. During the filling processes the two-phase flow patterns result from the competition among the inertia, adhesion and surface tension. The numerical results indicate that air bubble entrapment cannot be avoided by continuous pumping of the liquid. A pressure “pulse” in descending increments is necessary to eliminate air entrapment. Only by carefully “tuning” the appropriate balanced pressure drop across the microchannel at the last stage of pulsation, the liquid was able to contract into the small channel.

** † † ‡ § , The Lab-on-a-Chip Application Development (LOCAD) team at NASA’s Marshall Space Flight Center is utilizing LOC to support technology development specifically for space exploration. In this paper, we investigate both numerically and experimentally, the transient “filling” two-phase flow patterns in a protein trap chip (PTC) configuration. We will describe the design and operation of an integrated microchannel/PTC configuration. Specifically, the filling processes of a liquid inside an expanded chamber hosting a dammed-structure used to block micro beads for protein trapping are studied. Numerical simulations are performed for the movement of a liquid-gas two-phase flow inside the microchannel and the PTC. The 3-D numerical simulations were conducted using the free surface Volume of Fluid method (PLIC-VOF) which allows for the interface between two immiscible fluids to be simulated while incorporating the effects of surface tension. The results are presented in terms of the movement of the gas-liquid interface. During the filling processes the two-phase flow patterns result from the competition among the inertia, adhesion and surface tension. The effects of hydrophilicity through the contact angle among gas/liquid/solid interface are investigated systematically. An experimental flow visualization system was devised to observe the characteristics of the filling process. Detailed numerical model procedures, as well as experimental results/comparison will be described.

NASA's Marshall Space Flight Center (MSFC) Lab on a Chip Application Development LOCAD) team has worked with microfluidic technology for the past few years in an effort to support NASA's Mission. In that time, such microfluidic based Lab-on-a-Chip (LOC) systems have become common technology in clinical and diagnostic laboratories. The approach is most attractive due to its highly miniaturized platform and ability to perform reagent handling (i-e., dilution, mixing, separation) and diagnostics for multiple reactions in an integrated fashion. LOCAD, along with Caliper Life Sciences has successfully developed the first LOC device for macromolecular crystallization using a workstation acquired specifically for designing custom chips, the Caliper 42. LOCAD uses this, along with a novel MSFC-designed and built workstation for microfluidic development. The team has a cadre of LOC devices that can be used to perform initial feasibility testing to determine the efficacy of the LOC approach for a specific application. Once applicability has been established, the LOCAD team, along with the Army's Aviation and Missile Command microfabrication facility, can then begin to custom design and fabricate a device per the user's specifications. This presentation will highlight the LOCAD team's proven and unique expertise that has been utilized to provide end to end capabilities associated with applying microfluidics for applications that include robotic life detection instrumentation, crew health monitoring and microbial and environmental monitoring for human Exploration.

At Marshall Space Flight Center we have established a capability to investigate the use of microfluidics for space flight. The Lab-On-a-Chip Application Development (LOCAD) team has created a program for advancing Technology Readiness Levels (TRL) of 1 and 2 to TRL 6 and 7, quickly and economically for Lab-On-a-Chip (LOC) applications. Scientists and engineers can utilize LOCAD'S process to efficiently learn about microfluidics and determine if microfluidics is applicable to their needs. Once the applicability has been determined, LOCAD can then perform tests to develop the new fluidic protocols which are different from macro-scale chemical reaction protocols. With this information new micro-fluidic devices can be created and tested. Currently, LOCAD is focused on using microfluidics for both Environmental Monitoring & Control, and Medical Systems. Eventually, handheld portable units utilizing LOC technology will perform rapid tests to determine water quality, and microbial contamination levels. Since LOC technology is drastically reduced in physical size, it thereby reduces power, weight, volume, and sample requirements, a big advantage considering the resource constraints associated with spaceflight. Another one of LOCAD's current activities is the development of a microfluidic system to aid in the search for life on Mars.

The Iterative Biological Crystallization team in partnership with Caliper Technologies has produced a prototype microfluidic chip for batch crystallization that has been designed and tested. The chip is designed for the mixing and dispensing of up to five solutions with possible variation of the recipe being delivered to two growth wells. Developments that have led to the successful on-chip crystallization of a few model proteins have required investigative insight into many different areas, including fluid mixing dynamics, surface treatments, quantification and fidelity of reagent delivery. This presentation will encompass the ongoing studies and data accumulated toward these efforts.

At NASA's Marshall Space Flight Center, the Iterative Biological Crystallization (IBC) project has begun development on scientific hardware for macromolecular crystallization on the International Space Station (ISS). Currently ISS crystallization research is limited to solution recipes that were prepared on the ground prior to launch. The proposed hardware will conduct solution mixing and dispensing on board the ISS, be fully automated, and have imaging functions via remote commanding from the ground. Utilizing microfluidic technology, IBC will allow for on orbit iterations. The microfluidics LabChipo devices that have been developed, along with Caliper Technologies, will greatly benefit researchers by allowing for precise fluid handling of nano/pico liter sized volumes. IBC will maximize the amount of science return by utilizing the microfluidic approach and be a valuable tool to structural biologists investigating medically relevant projects.

A team from the structural biology group located at the Marshall Space Flight Center in Huntsville Alabama is developing a platform suitable for cross-disciplinary microchannel research. The original objective of this engineering development effort was to deliver a multi-user flight-certified facility for iterative investigations of protein crystal growth; that is, Iterative Biological Crystallization. However, the unique capabilities of this facility are not limited to the low-gravity structural biology research community. Microchannel-based research in a number of other areas may be greatly accelerated through use of this facility. In particular, the potential for gas-liquid flow investigations and cellular biological research utilizing the exceptional pressure control and simplified coupling to macroscale diagnostics inherent with the facility will be discussed. Also noted will be the opportunities for research-specific modifications to the microchannel configuration, control and diagnostics.

We are developing a novel technique with which we have grown diffraction quality protein crystals in very small volumes, utilizing chip-based, microfluidic (LabChip) technology. With this technology volumes smaller than achievable with any laboratory pipette can be dispensed with high accuracy. We have performed a feasibility study in which we crystallized several proteins with the aid of a LabChip device. The protein crystals are of excellent quality as shown by X-ray diffraction. The advantages of this new technology include improved accuracy of dispensing for small volumes, complete mixing of solution constituents without bubble formation, highly repeatable recipe and growth condition replication, and easy automation of the method. We have designed a first LabChip device specifically for protein crystallization in batch mode and can reliably dispense and mix from a range of solution constituents. We are currently testing this design. Upon completion additional crystallization techniques, such as vapor diffusion and liquid-liquid diffusion will be accommodated. Macromolecular crystallization using microfluidic technology is envisioned as a fully automated system, which will use the 'tele-science' concept of remote operation and will be developed into a research facility aboard the International Space Station.

The first flight of NASA's new exploration-class launch vehicle, the Space Launch System (SLS), will test a myriad of systems designed to enable the next generation of deep space human spaceflight, while also providing the rare opportunity for 13 6U CubeSat-class payloads to be deployed in several locations along the flight path. The first mission of SLS and NASA's new Orion crew vehicle, Exploration Mission-1 (EM-1), will launch from upgraded facilities at Kennedy Space Center no earlier than fiscal year 2020. The initial Block 1 configuration for EM-1 will be capable of lofting at least 26 metric tons (t) of payload to the moon, with propulsion supplied by twin five-segment solid rocket boosters, four RS-25 engines and an Interim Cryogenic Propulsion Stage (ICPS). SLS will send Orion into a distant retrograde lunar orbit, paving the way for future missions to cislunar space and eventually Mars. The multidisciplinary small satellites for EM-1 derive from NASA research, as well as from international partners, industry and academia. Research subjects for the various smallsats include the moon, sun and an asteroid. Science objectives vary from characterizing the effects of radiation on living organisms (yeast) to landing the smallest spacecraft yet on the moon to supporting space weather research. Some of the payloads are technology demonstrations that will pave the way for more ambitious future missions that will be deployed by the more powerful SLS Block 1B configuration.