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NASA Ames has developed very small-sized oxygen sensors made of a graphene and titanium dioxide (TiO₂) hybrid material. With ultraviolet (UV) illumination, these sensors are capable of detecting oxygen (O₂) gas at room temperature and at ambient pressure. The sensors are able to detect oxygen at concentrations ranging from about 0.2% to about 10% by volume under 365nm UV light, and at concentrations ranging from 0.4% to 20% by volume under short wave 254nm UV light. These sensors have fast response and recovery times and can also be used to detect ozone. This unique room temperature O₂ sensor provides significant advantages in O₂ sensing applications, especially those applications where high operating temperature requirements cannot be met, or would result in inefficient manufacturing processes. Since graphene is not intrinsically responsive to O₂, and TiO₂ is not responsive to oxygen at room temperature, the materials are first synthesized as a hybrid material. The synthesized graphene- TiO₂ hybrid material is then ultrasonicated and then drop-casted onto a series of Interdigitated Electrodes (IDE) to form the sensors. Ultrasonication ensures effective charge transfer at the graphene- TiO₂ interphase. The graphene and the titanium dioxide may be present in the composite material in different ratios to ensure optimal oxygen detection. It is the combination of graphene with TiO2 that yields a semiconducting material capable of O₂ sensing at room-temperature operation.

The manufacturing process, building on techniques showcased in LEW-TOPS-151, employs a novel acoustic mixing technique to coat spherical C103 powder particles with a uniform distribution of sub-200 nanometer yttria particles. During laser powder bed fusion additive manufacturing, layer-by-layer remelting disperses these yttria particles uniformly throughout the component microstructure. This eliminates the expensive, time-consuming mechanical alloying steps traditionally required for ODS alloys while enabling near-net-shape fabrication of complex geometries. Performance testing demonstrates substantial improvements: GRC103y exhibits double the yield strength at 800°C and 1.5x the yield strength at 1,400°C compared to baseline C103. The alloy also shows superior thermal stability: after one hour at 1,500°C, GRC103y retains 90% of its room temperature strength compared to only 67% for C103. Preliminary creep testing at 1,300°C and a stress of 50 MPa indicates significant improvements in creep resistance by 2539 times over baseline C103. Furthermore, GRC103y maintains excellent formability, allowing manufacturers to use traditional fabrication methods when desired. While NASA originally developed GRC103y for rocket propulsion and hypersonic vehicle applications, the alloy offers value across multiple industries. Aerospace companies can achieve weight savings or push systems to higher temperatures, while the alloy's compatibility with commercial oxidation coatings makes it suitable for environments requiring oxidation protection. GRC103y is currently available for patent licensing.

ARC ANGEL is an active robotic system like ARGOS; however, its electric motor is not mounted overhead to a runway and bridge system, but instead is mounted to the test subject’s backpack-like PLSS where the motor(s) supplies real-time actuation torque off-loading to the upper arms via cabling. If a test subject picks-up a hammer, the system will react immediately to offload the weight of the hammer relative to the programmed environment. The ARC ANGEL system is comprised of an electric motor(s), soft goods, electronics hardware, firmware, and software. To provide a smoothly operating arm offloading analog and optimize system performance, engineers at JSC coded software that leverages kinematic algorithms and closed-loop architecture for motor control, along with custom computer language scripts to ingest sensor data. This allows ARC ANGEL’s subsystems to be seamlessly integrated and accurately simulate one to zero G environments. During operation, compact tension sensors and inertial measurement units detect arm weight and motion and provide a closed-loop control system that feeds data to a single-board computer and requisite firmware for processing. A custom graphical user interface was also developed in-house to provide controls for inputting desired arm offload values. Additionally, ARC ANGEL features its own power supply that provides power to its subcomponents without external cables. This allows the ability to function independently from ARGOS and further lends itself to potential terrestrial applications. This work directly correlates to active exosuit development that is being implemented for rehabilitation and/or assistive medical devices. ARC ANGEL is essentially providing a desired assistance (offload) while maintaining a subject’s full range of motion. The system hardware and software can be modified to custom-fit an individual without a spacesuit and toward limb-assisted movement – not just arm offloading. ARC ANGEL may already meet a higher physical demand and robustness given that it is engineered to perform in challenging environments with greater loads. ARC ANGEL is at a technology readiness level (TRL) 5 (component and/or breadboard validation in laboratory environment) and is now available for patent licensing. Please note that NASA does not manufacture products itself for commercial sale.