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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Engineering CoO x ‑Based Self-Supported Anodes for Pure-Water-Fed Anion-Exchange-Membrane Electrolysis

Commercial membrane electrolyzers rely on acidic fluorocarbon membranes and ionomers, requiring the use of expensive IrO x -based oxygen-evolution catalysts. Anion-exchange-membrane water electrolyzers (AEMWEs) operate in an alkaline environment, enabling the use of non-precious-metal catalysts. Here, we study and engineer CoO x -based catalyst-coated anodes deposited via hydrothermal synthesis directly onto porous transport layers both with and without thermal annealing. The self-supported, nanoneedle-structured Co3O4 anode, formed by annealing the as-synthesized cobalt carbonate hydroxide, Co­(CO3) x (OH) y , outperforms the baseline Co3O4 nanoparticle ink-based anode in pure-water-fed AEMWE due to the improved catalyst-layer continuity and thus number of electroactive Co species. The as-synthesized and unannealed Co­(CO3) x (OH) y , however, appears to undergo substantial conversion to a more-active CoO x (OH) y phase predominantly at the surface, with nominal Co3+ present and higher electrical conductivity, lowering the cell voltage to ∼200 mV at 1.0 A·cm–2 in pure-water-fed AEMWE compared to the conventional Co3O4 nanoparticle anodes. We analyze the differences in electrode electrochemical response between pure-water and KOH feed modes, finding distinct activation and degradation modes. The Co­(CO3) x (OH) y anode shows significant activation and slower degradation linked to the conversion to oxyhydroxide. We propose catalyst layer designs that promote both hydroxide and electron transport, alongside interfacial engineering strategies to obtain high performance while mitigating anode degradation.

anion-exchange-membrane water electrolysis↗
DOE OSTI2022

Slice-Write

SAND2022-1477 O Slice-Write is an extremely powerful toolpath generation technology for the extrusion 3D printing community. This application was developed as a standalone post-processor capable of interpreting and translating gcode output from Ultimaker Cura, an open-source slicing application for additive manufacturing, not designed or intended for direct ink write (DIW) printing. Slice-Write can convert output gcode from Cura into a format compatible with Aerotech-based motion control DIW printing platforms. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Roach, Devin↗
DOE OSTI2025

Coaxial Direct Ink Writing of Cholesteric Liquid Crystal Elastomers in 3D Architectures

Abstract Cholesteric liquid crystal elastomers (CLCEs) hold great promise for mechanochromic applications in anti‐counterfeiting, smart textiles, and soft robotics, thanks to the structural color and elasticity. While CLCEs are printed via direct ink writing (DIW) to fabricate free‐standing films, complex 3D structures are not fabricated due to the opposing rheological properties necessary for cholesteric alignment and multilayer stacking. Here, 3D CLCE structures are realized by utilizing coaxial DIW to print a CLC ink within a silicone ink. By tailoring the ink compositions, and thus, the rheological properties, the cholesteric phase rapidly forms without an annealing step, while the silicone shell provides encapsulation and support to the CLCE core, allowing for layer‐by‐layer printing of self‐supported 3D structures. As a demonstration, free‐standing bistable thin‐shell domes are printed. Color changes due to compressive and tensile stresses can be witnessed from the top and bottom of the inverted domes, respectively. When the domes are arranged in an array and inverted, they can snap back to their base state by uniaxial stretching, thereby functioning as mechanical sensors with memory. The additive manufacturing platform enables the rapid fabrication of 3D mechanochromic sensors thereby expanding the realm of potential applications for CLCEs.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Development of Roll-to-Roll Simultaneous Multilayer Deposition Methods for Solid-state Electrochemical Devices using Highly Particulate Loaded Aqueous Inks

A platform for simultaneous multilayer roll-to-roll coating was developed for solid-state electrochemical devices through Saint-Gobain’s Solid Oxide Fuel Cell. Six wet layers were successfully coated one top of another using multilayer slide coating following design rules developed through a step-wise approach. Solid oxide fuel cells, which comprise of engineered ceramic films, were made with dual slot and multi-layer slide dies and shown to have similar performance to cells made with incumbent coating methods. Additionally, interlayers were coated below their individual singular low flow limits using simultaneous multilayer coating.

08 HYDROGEN↗
DOE OSTI2023

Predicting Deposition Rate and Closing the Loop on Aerosol Jet Printing with In‐Line Light Scattering Measurements

Aerosol jet printing is a compelling noncontact, digital manufacturing technology for flexible, hybrid, and conformal electronics, but batch‐to‐batch variability and process drift inhibit systematic study and translation to production environments. Emerging measurement techniques for the aerosol volume fraction, a key parameter governing deposition rate, have shown promise for real‐time response, including a recent demonstration of human‐in‐the‐loop control. By integrating improved light scattering measurements with custom software, a robust environment for real‐time monitoring is established and fully automated closed‐loop control over the deposition rate during printing is enabled. The physical basis for scattering measurements as a feedback source is examined and the quantitative insight this provides for ink development and fundamental process studies is highlighted. Three candidate process variables for closed‐loop control, namely the atomizer voltage, carrier gas flow rate, and print speed, are then evaluated. The atomizer voltage demonstrates the best extended duration validity because it addresses atomization variability directly, but carrier gas flow rate and print speed provide faster and more deterministic responses. This methodology is then demonstrated for electrical properties using a silver nanoparticle ink, maintaining 98% of printed patterns within 10% of the mean resistance value over 3 h of printing.

36 MATERIALS SCIENCE↗
DOE OSTI2020

AGR-5/6/7 Capsule Leach Station Hardware Qualification - Phase 1

Procedural changes to this document shall be logged and justified using the EQP Change Log below. Typographical errors do not need to be logged, but do require the Lead Engineers initials and date. Each entry shall be numbered (i.e., CN #1) for identification in the left-hand margin of the table. Each entry may include individual or groups of related procedural changes. Changes to the EQP shall made by pen and ink and/or addition of additional pages depending on the extent of the change.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2025

Additive manufacturing of high‐density silicon carbide ceramics through post‐processing spark plasma sintering

This research advances the field of additive manufacturing (AM) of silicon carbide (SiC) ceramics by integrating spark plasma sintering (SPS) to enhance material density, mechanical strength, and thermal properties. Traditional AM techniques struggle to achieve the high‐density SiC required for demanding applications, such as aerospace engineering, where high thermal conductivity and mechanical strength are paramount. Here, our study addresses these challenges by incorporating SPS as a post‐processing step, achieving near‐theoretical maximum densities and significantly reducing porosity, thereby resulting in outstanding thermal conductivity in SiC ceramics. We developed a specialized SiC ink optimized for 3D printing, ensuring structural integrity after deposition through tailored rheological properties. The application of SPS facilitates rapid, uniform sintering, essential for attaining superior density, mechanical properties, and thermal performance. Our experimental results, confirmed through scanning electron microscopy analysis, demonstrate significant microstructural properties, mechanical strength, and thermal conductivity, showcasing the effectiveness of integrating SPS in AM processes. This innovative approach not only expands the capabilities of AM in producing complex, high‐density ceramic structures but also broadens the potential applications of SiC in demanding environments.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Volumetric Additive Manufacturing of Gradient Composition Glass

Advanced optics, such as lasers or cameras, are currently limited by geometric or compositional restrictions on the silica glass components that act as focusing or refracting lenses. Currently, these glass components must be made of one homogenous material in a range of shapes and sizes limited by a few specialized vendors. However, additional flexibility and customization of these optical components could significantly improve the performance of these devices and expand the design space available to optics engineers, as would the capability to locally change the optical properties of these glass components by changing the composition of the glass as a function of location. To this end, we have developed a method to print and process gradient composition glass, using volumetric additive manufacturing (VAM) and direct ink writing (DIW), on-site at Lawrence Livermore National Lab.

36 MATERIALS SCIENCE↗
DOE OSTI2020

High Speed In-situ X-ray Imaging of 3D Freeze Printing of Aerogels

3D freeze printing (3DFP) combines drop-on-demand (DOD) inkjet printing with freeze casting to fabricate lightweight and multifunctional aerogels with customized geometries. Freeze casting is an efficient and easily implemented method capable of fabricating porous, sponge-like structures for many different applications. This process enables tailoring the microstructure of the final product (i.e., pore morphology, alignment, average size distribution, etc.) by controlling the fabrication conditions and freezing kinetics. Furthermore, its combination with DOD printing provides the capability of engineering the macrostructure without relying on a mold as reported for 3D freeze-printed aerogels made from graphene, silver nanowires, and other nanocomposites. In this paper, we performed in-situ X-ray imaging to understand the inside process dynamics in 3DFP using a commercially available colloidal silica ink. We investigated the 3DFP process with the following hierarchy: first, single droplets; then, uniform lines obtained from coalescence of droplets; and finally, three consecutive lines deposited layer by layer. With the help of X-ray imaging, the importance of the balance between material deposition and freezing rates was shown in-situ by the observation inside of the freeze front following the tip of the printed line. The effects of the substrate temperature on the elimination of undesired interfacial boundaries were also shown by the observed ice crystals penetrating from lower to upper layer.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Boron‐polymer composites engineered for compression molding, foaming, and additive manufacturing

Abstract Boron (specifically 10 B) is the element of choice to shield thermal neutrons due to its large (n, α) cross‐section; however, very few polymer composites containing high boron concentrations are available. This study aimed to determine the maximum possible amount of boron that could be introduced into a polymer matrix. Diverse manufacturing techniques, ranging from additive manufacturing to compression molding, were employed to fabricate inks and filaments for 3D printing, foams, and flexible pads. Composites using siloxanes, poly(lactic acid), and acrylonitrile butadiene styrene containing up to 80 wt% boron were sucessufully fabricated. The addition of known plasticizers (polyethylene glycol) and reinforcing agents (carbon nanofibers and fumed silica) helped to overcome fabrication problems such as clogging of the printing nozzle or crumbling of compression molded parts. In addition, the thermal‐mechanical properties of these novel boron composites were determined and shown to vary according to boron concentration, presence of additives, and fabrication techniques utilized.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Rising Water Levels and Vegetation Shifts Drive Substantial Reductions in Methane Emissions and Carbon Dioxide Uptake in a Great Lakes Coastal Freshwater Wetland

ABSTRACT Coastal freshwater wetlands are critical ecosystems for both local and global carbon cycles, sequestering substantial carbon while also emitting methane (CH 4 ) due to anoxic conditions. Estuarine freshwater wetlands face unique challenges from fluctuating water levels, which influence water quality, vegetation, and carbon cycling. However, the response of CH 4 fluxes and their drivers to altered hydrology and vegetation remains unclear, hindering mechanistic modeling. To address these knowledge gaps, we studied an estuarine freshwater wetland in the Great Lakes region, where rising water levels led to a vegetation shift from emergent Typha dominance in 2015–2016 to floating‐leaved species in 2020–2022. Using eddy covariance flux measurements during the peak growing season (June–September) of both periods, we observed a 60% decrease in CH 4 emissions, from 81 ± 4 g C m −2 in 2015–2016 to 31 ± 3 g C m −2 in 2020–2022. This decline was driven by two main factors: (1) higher water levels, which suppressed ebullitive fluxes via increased hydrostatic pressure and extended CH 4 residence time, enhancing oxidation potential in the water column; and (2) reduced CH 4 conductance through plants. Net carbon dioxide (CO 2 ) uptake decreased by 90%, from −267 ± 26 g C m −2 in 2015–2016 to −27 ± 49 g C m −2 in 2020–2022. Additionally, diel CH 4 flux patterns shifted, with a distinct morning peak observed in 2015–2016 but absent in 2020–2022, suggesting changes in plant‐mediated transport and a potential decoupling from photosynthesis. The dominant factors influencing CH 4 fluxes shifted from water temperature and gross primary productivity in 2015–2016 to atmospheric pressure in 2020–2022, suggesting an increased role of ebullition as a primary transport pathway. Our results demonstrate that changes in water levels and vegetation can substantially alter CH 4 and CO 2 fluxes in coastal freshwater wetlands, underscoring the critical role of hydrological shifts in driving carbon dynamics in these ecosystems.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

Scalable, low-cost ink-based processing of high-performance silver selenide thermoelectrics

The growing global energy demand and its accelerating contribution to climate change emphasize the urgent need for sustainable energy conversion/harvesting technologies. Thermoelectric (TE) devices offer a compelling route to directly convert waste heat into electricity and enable solid-state cooling without moving parts or harmful refrigerants. Achieving their full potential requires not only higher TE performance (zT) but also scalable, low-cost manufacturing processes. Here, we introduce a transformative ink-based processing approach for scalable manufacturing of high-performance silver selenide-based TE materials and devices. Using a simple, high-throughput ink-mixing and blade coating strategy, our Ag 2 Se-based materials under the optimized composition and processing conditions yield an ultrahigh room-temperature power factor of 2.8 mW m −1 K −2 , over 100% higher than baseline samples and a reproducible figure of merit zT of 1 at room temperature. A thermoelectric generator (TEG) achieves a very competitive power density of 112 mW cm −2 at a 90 °C temperature difference between the hot and cold sides of the device, which is among the highest reported for silver selenide-based TE devices to date. This facile, scalable ink-based processing establishes a practical pathway toward industrial-scale manufacturing and widespread adoption of thermoelectric devices, advancing sustainable energy technologies.

Bappy, Md. Omarsany [University of Notre Dame, IN ↗