17 research outputs found
Literature Review of Disinfection Techniques For Water Treatment
No full textNilab Azim, University of Central Florida, USAngie Diaz, Amentum, USWenyan Li, Amentum, USTesia Irwin, The Bionetics Corporation, USLuz Calle, National Aeronautics and Space Administration, USMichael Callahan, National Aeronautics and Space Administration (NASA), USALiterature Review of Disinfection Techniques For Water TreatmentThe proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.Water treatment is a developing concern, both terrestrially and in spacecraft, as exploration missions extend in time and distance. Current biofilm control is limited for long-term applications. To optimize biocides for present and future space exploration vehicles, a thorough understanding of common and traditional disinfectant techniques is required. This review is focused on the three fundamental disinfection techniques: chemical, physical, and biological. Mechanisms, advantages, disadvantages, and specific properties of each major technique, as well as their studied effect on established biofilms, are also considered. This paper provides a general background on disinfectants and some information on effects on biofilms that can be useful to develop innovative ideas for state-of-the-art disinfection techniques for water treatment in specific environments, such as those currently posing mission risks as well as for future spacecraft water system development
Polymer-based and Functionalized 3D Microelectrode Array (MEA) Biosensors
No full textMicrophysiological systems are three-dimensional (3D) in vitro systems that recapitulate crucial biological aspects of cell heterogeneity and native tissue architecture by mimicking complex structures that are impossible in two-dimensional (2D) cell cultures. Microelectrode arrays (MEAs) are biosensors used to spatially and temporally monitor the activity of microphysiological systems by transducing cellular signals into electronic signals to provide quantitative data on the in vitro system. Conventional MEAs are typically planar in nature, however, 3D MEAs offer several advantages such as better simulation of an in vivo cellular environment and improved signal-to-noise ratio and cell-electrode coupling. MEA fabrication utilizing traditional cleanroom methods is rather extensive, expensive, and specialized, therefore this thesis presents a transition from 2D MEAs fabricated via the cleanroom approach to 3D MEAs fabricated via the makerspace approach utilizing polymers. The first study in the thesis discussed the fabrication and characterization of 2D MEA devices using cleanroom methods and investigated post-processing methods to address limitations that arise for planar devices. The next study introduced the makerspace approach, where benchtop techniques were used to successfully fabricate and characterize a fully functional 3D MEA. A subsequent study investigated another benchtop method to define an electrical insulation using a pour-spin method of polystyrene solution. However, there was a challenge of adhesion of the PS to the substrate, which was improved by both utilizing another type of printer and functionalizing these surfaces with polydopamine. In the final study of the thesis, a benchtop technique called electrospinning was used to define synthetic polymer-based nanofibers atop of the 3D MEAs to simulate extracellular matrices as well as demonstrate their potential as drug delivery systems. This thesis demonstrates the highly versatile nature of makerspace microfabrication utilizing polymers to allow for new processes that offer advanced functionalities when producing microdevices such as 3D MEAs interfacing with microphysiological systems
Microgravity Effect on Bacterial Growth: Further Clarification of the Underlying Mechanism
No full textWenyan Li, NASA Kennedy Space Center, USAAngie Diaz, NASA Kennedy Space Center, USATesia Irwin, NASA Kennedy Space Center, USANilab Azim, NASA Kennedy Space Center, USAAubrie O'Rourke, NASA Kennedy Space Center, USAICES303: Physico-Chemical Life Support- Water Recovery & Management Systems- Technology and Process DevelopmentThe 53rd International Conference on Environmental Systems was held in Louisville, Kentucky, USA, on 21 July 2024 through 25 July 2024.Gravity interacts with other physical environmental factors to impact the formation of today's Earth and contribute to biological variations between water and land species. Microbes, with their simple structures and small sizes, are expected to be less gravity-sensitive than larger species. However, microgravity can greatly impact the mass transfer and interface behavior in the extracellular environment, and various effects of spaceflight on bacterial growth have been observed. Our earlier literature review summarizes the systematic efforts to understand the spaceflight effect on microbial growth through the extracellular mass transfer mechanism and provides an in-depth literature review to address some discrepancies observed in the literature. This paper analyzes the effects of microgravity on the extracellular environment, and their potential effect on bacterial growth, to further clarify the underlying mechanism of the microgravity effect on bacterial growth
Silver Foam: A Novel Approach for Long-Term Passive Dosing of Biocide in Spacecraft Potable Water Systems – Update 2023
No full textTesia Irwin , NASA Kennedy Space Center, USAAngie Diaz , NASA Kennedy Space Center, USAJennifer Gooden , NASA Kennedy Space Center, USAMary Hummerick , NASA Kennedy Space Center, USAWenyan Li , NASA Kennedy Space Center, USANilab Azim , NASA Kennedy Space Center, USADeborah Essumang , NASA Kennedy Space Center, USAMichael Callahan , NASA Johnson Space Center, USAICES303: Physio-Chemical Life Support- Water Recovery & Management Systems- Technology and Process DevelopmentThe 52nd International Conference on Environmental Systems was held in Calgary, Canada, on 16 July 2023 through 20 July 2023.A spacecraft water disinfection system that suitable for extended length space exploration, should prevent or control the growth of microbes, prevent or limit biofilm formation, and prevent microbiologically influenced corrosion. In addition, the system should have minimal maintenance requirements, be chemically compatible with all materials in contact with the water, be safe for human consumption, and be suitable to be shared across international spacecraft platforms and mission architectures. Ionic silver is a proven broad-spectrum potable water biocide under investigation for future exploration missions. The competing technology for dosing silver ions in future water systems is based on actively dosing the ions via electrolytic production. Several challenges with this approach have prompted additional investigations into alternative dosing techniques. Controlled-release technology is an attractive option for developing a high-reliability passive silver dosing device. This paper describes the continued development of a nanoparticle/polyurethane (NP/PU) composite foam for the controlled release of silver ions, and is intended to build upon the 2022 International Conference on Environmental Systems (ICES) paper number 97. This paper provides the technical background and performance test results of ongoing long-term silver ion release testing, microbial check valve (MCV) function, and disinfection function during system dormancy from the silver chloride (AgCl) NP/PU composite foams. The ultimate goal of the project is to develop a stable and reliable passive dosing silver ion release device for use in future spacecraft potable water systems
Environmental Testing of a Fully Automated Carbothermal Reactor for Lunar Oxygen Production
No full textNathan P. Haggerty, Sierra Space Corporation, United StatesBrant C. White, Sierra Space Corporation, United StatesAaron Paz, NASA Johnson Space Center (JSC), United StatesDesmond O'Connor, NASA Johnson Space Center (JSC), United StatesNilab Azim, NASA Kennedy Space Center (KSC), United StatesJanine Captain, NASA Kennedy Space Center (KSC), United StatesICES308: Advanced Technologies for In-Situ Resource
UtilizationThe 54th International Conference on Environmental Systems was held in Prague, Czechia, on 13 July 2025 through 17 July 2025.Oxygen comprises the majority of propellant mass required
for ascent from the lunar surface and for in-space chemical
propulsion. Using in-situ resource utilization (ISRU)
technologies to produce oxygen on the moon enables a robust
lunar economy through a dramatic reduction in lunar launch
costs. In the Summer of 2024 Sierra Space completed thermal
vacuum (TVAC) testing of a flight-like Carbothermal Oxygen
Production Reactor (COPR) through a NASA Tipping Point
program.
The COPR reactor uses a mass efficient, scalable
architecture optimized for a lunar technology demonstration
mission. Concentrated solar energy is directly applied to
the lunar regolith simulant. The insulating material
properties of the regolith isolate the corrosive molten
material from the reactor walls and other hardware. This
approach allows for a completely passive thermal control
system where high temperature (~1800°C) carbothermal
processing is performed without requiring exotic materials
or complex cooling systems. The reactor also includes an
end-to-end automated solid material handling system capable
of metering the lunar regolith simulant from a supply
hopper into a pressurized volume, weighing it, distributing
it into the carbothermal reactor, and removing the reduced
metallic slag.
Sierra Space demonstrated repeated use of the automated
material handling, gas handling and carbothermal reduction
processing systems inside NASA JSC’s “dirty” TVAC chamber
while at the relevant lunar topographical, vacuum, and
temperature conditions. This testing matured key hardware
to TRL 6. Oxygen extraction and performance measurements
were taken by the NASA KSC Mass Spectrometer Observing
Lunar Operations (MSolo) team using a commercial version of
their flight instrument. Oxygen extraction energy
efficiency and production yield from regolith exceeded the
program goals.
The COPR system will be integrated with a flight forward
solar concentrator, optical shutter, gas analysis system,
avionics, and software as a part of the NASA CaRD program
integrated testing in early 2025
Silver Foam: A Novel Approach for Long-Term Passive Dosing of Biocide in Spacecraft Potable Water Systems – Update 2024
No full textTesia D. Irwin, NASA Kennedy Space Center, USAAngie Diaz, NASA Kennedy Space Center, USAJennifer Gooden, NASA Kennedy Space Center, USARachael Atanowski, NASA Kennedy Space Center, USAMary Hummerick, NASA Kennedy Space Center, USAWenyan Li, NASA Kennedy Space Center, USANilab Azim, NASA Kennedy Space Center, USADeborah Essumang, NASA Kennedy Space Center, USAMichael R. Callahan, NASA Johnson Space Center (JSC), USAA spacecraft water disinfection system, suitable for extended length space exploration, should prevent or control the growth of microbes, prevent or limit biofilm formation, and prevent microbiologically influenced corrosion. In addition, the system should have minimal maintenance requirements, be chemically compatible with all materials in contact with the water, be safe for human consumption, and be suitable to be shared across international spacecraft platforms and mission architectures. Silver ions are a proven broad-spectrum potable water biocide under investigation for future exploration missions. The competing technology for dosing silver ions in future water systems is based on actively dosing the ions via electrolytic production. Several challenges with this approach have prompted additional investigations into alternative dosing techniques. Control-release technology is an attractive option for developing a high-reliability passive silver dosing device. This paper describes the continued development of a nanoparticle/polyurethane (NP/PU) composite foam for the controlled release of silver ions and is intended to build upon the 2023 International Conference on Environmental Systems (ICES) paper number 251. This paper provides the technical background and performance results for the product variability testing and microbial check valve (MCV) testing of the silver chloride (AgCl) NP/PU composite foams, referred to as AgFoams. The ultimate goal of the project is to develop a stable and reliable passive dosing silver ion release device for use in future spacecraft potable water systems
Jewish and Christian Voices in English Reformation Biblical Drama: Enacting Family and Monarch
No full textFABRICATION AND CHARACTERIZATION OF 3D PRINTED, 3D MICROELECTRODE ARRAYS WITH SPIN COATED INSULATION AND FUNCTIONAL ELECTROSPUN 3D SCAFFOLDS FOR "DISEASE IN A DISH" AND "ORGAN ON A CHIP" MODELS
No full textWe demonstrate a new fabrication technology for 3D Microelectrode Arrays (MEAs) to stimulate and record electrophysiological activity from cellular networks in-vitro. Electrospun Polyethylene Terephthalate (PET) 3D scaffolds are coupled to the fabricated MEAs which make them fully functional for “disease in a dish” and “organ on a chip” models to promote cell/tissue growth and regeneration. The microfabrication technology involves 3D towers realized by 3D printing and a metallization layer, defined by stencil mask evaporation techniques. Multiple insulation strategies are reported: a drop-casted/spin-coated 3D layer of Polystyrene (PS) and an evaporated layer of SiO2, both of which are laser micromachined to realize the 3D microelectrodes
MULTI-MODAL MICROELECTRODE ARRAYS FOR THE INVESTIGATION OF PROTEIN ACTIN'S ELECTRO-MECHANOSENSING MECHANISMS TOWARD NEURODEGENERATIVE DISEASE MODELS ON A CHIP
No full textWe have developed multi-modal Microelectrode Arrays (MEAs) with electrodes and microfluidics, with successful manipulation of actin filaments and bundles onto the devices for electro-mechanosensing studies. The application of our MEAs to the characterization of actin filaments/bundles will allow fundamental understanding of actin cytoskeleton’s mechanical and electrodynamic properties in neurodegenerative disease signatures on a chip
Four-Dimensional Printing of Multi-Material Origami and Kirigami-Inspired Hydrogel Self-Folding Structures
No full textFour-dimensional printing refers to a process through which a 3D printed object transforms from one structure into another through the influence of an external energy input. Self-folding structures have been extensively studied to advance 3D printing technology into 4D using stimuli-responsive polymers. Designing and applying self-folding structures requires an understanding of the material properties so that the structural designs can be tailored to the targeted applications. Poly(N-iso-propylacrylamide) (PNIPAM) was used as the thermo-responsive material in this study to 3D print hydrogel samples that can bend or fold with temperature changes. A double-layer printed structure, with PNIPAM as the self-folding layer and polyethylene glycol (PEG) as the supporting layer, provided the mechanical robustness and overall flexibility to accommodate geometric changes. The mechanical properties of the multi-material 3D printing were tested to confirm the contribution of the PEG support to the double-layer system. The desired folding of the structures, as a response to temperature changes, was obtained by adding kirigami-inspired cuts to the design. An excellent shape-shifting capability was obtained by tuning the design. The experimental observations were supported by COMSOL Multiphysics® software simulations, predicting the control over the folding of the double-layer systems
