Tech Briefs

Connection and Repair Techniques for Capillary Tubing in Restrictive Areas and Gas Chromatography Applications

John F. Kennedy Space Center, Florida Capillary columns offer challenges in gas chromatography (GC) work due to their small size and fragile nature. Typical repair techniques to join two capillary columns require cumbersome metal fittings. This solution is not applicable in all situations due to size and mass limitations. Another repair or joint technique involves the use of polyimide glue with a tapered glass union. Without the bulky glass fitting, this technique is difficult to perform without plugging the column; the low-viscosity glue wicks up the capillary column and fills the small opening of the joint. Polyimide is also a problem due to its hydrolysis when trying to analyze water; the polyimide glue interacts with the water in the sample and affects the analysis. These solutions don’t support a repair of capillary columns for water analysis in a small gas chromatograph module.

Posted in: Briefs, Manufacturing & Prototyping

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Self-Latching Piezocomposite Actuator

Langley Research Center, Hampton, Virginia NASA’s Langley Research Center has developed a self-latching piezocomposite actuator. The self-latching nature of this invention allows for piezo actuators that do not require constant power draw. Among other applications, the invention is well suited for use in aerodynamic control surfaces and engine inlets. The technology is a self-latching piezoelectric actuator with power-off, set-and-hold capability. Integrated into an aerodynamic control surface or engine inlet, the self-latching piezocomposite actuator may function as a trim tab, variable camber airfoil, vortex generator, or winglet with adjustable shapes. Deflections could be made in-flight, and set and maintained (latched) without a constant power draw. Current piezo actuators require constant power to control and manage their electric fields. The control device leverages the shape memory behavior (specifically, the remnant stress-strain behavior) to create a morphing actuator that changes and holds the new shape with no applied control signal.

Posted in: Briefs, Mechanical Components, Machinery & Automation

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Active Response Gravity Offload and Method

The technology has commercial possibilities wherever individuals have to interact with heavy objects within a confined volume. Lyndon B. Johnson Space Center, Houston, Texas To train astronauts to live and work in the weightless environment on the International Space Station, NASA employs a number of techniques and facilities that simulate microgravity. Engineers at the NASA Johnson Space Center (JSC) have developed a new system called the Active Response Gravity Offload System (ARGOS) that provides a simulated reduced gravity environment within a confined interior volume for astronauts to move about and/or equipment to be moved about as if they were in a different gravity field. Each astronaut/item is connected to an overhead crane system that senses their actions (walking or jumping, for example) and then lifts, moves, and descends them as if they had performed the action in a specified reduced gravity.

Posted in: Briefs, Mechanical Components, Machinery & Automation

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Fluid Harmonic Absorber

These devices can be used in multistory buildings, towers, bridges, offshore oil rigs, water tanks, and marine applications. Marshall Space Flight Center, Alabama NASA Marshall Space Flight Center’s Fluid Structure Coupling (FSC) technology is a highly efficient and passive method to control the way fluids and structures communicate and dictate the behavior of a system. This technology has the demonstrated potential to mitigate a multitude of different types of vibration issues, and can be applied anywhere internal or external fluids interact with physical structures. For example, in a multistory building, water from a rooftop tank or swimming pool could be used to mitigate seismic or wind-induced vibration by simply adding an FSC device that controls the way the building engages the water.

Posted in: Briefs, Mechanical Components, Machinery & Automation

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Variable-Aperture Reciprocating Reed Valve

Marshall Space Flight Center, Alabama NASA’s Marshall Space Flight Center engineers have developed a new reed valve for controlling fluid flow back and forth between two chambers. The VARR valve provides two-way flow that is proportional to flow demand. As the pressure gradient builds on one side, the reed valve responds by opening an amount that is proportionate to the gradient, or demand, allowing bidirectional flow. Some mechanical and fluid systems that rely on the controlled flow of fluids between chambers will benefit from the new design. Compared to current fixed-orifice devices, VARR may expand the performance envelope by offering a more continuous flow response in applications in which the pressure environment is constantly changing. Proportional two-way flow can enable a fine-tuned system response to pressure building on one side of the valve. In these changing gradient conditions, the reed valve is better than fixed-sized orifices, which are optimized for one flow condition and are likely to over- or under-restrict flow for all other flow gradients.

Posted in: Briefs, Mechanical Components, Machinery & Automation

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Passive, Integrated, Sublimator-Driven Coldplate

Marshall Space Flight Center, Alabama Spacecraft thermal control systems typically perform three key functions — heat acquisition, heat transport, and heat rejection — in addition to those of insulation, heat generation, and heat storage. In a typical pumped fluid-loop spacecraft thermal control system, heat is acquired from heat-generating equipment via coldplates, transported via pumps and cooling lines, and rejected to space via radiators, evaporators, and/or sublimators. Combining all three of these functions into one hardware component can provide system mass savings by combining multiple pieces of hardware into a single piece, and providing additional fault tolerance without the need for redundant hardware.

Posted in: Briefs, Mechanical Components, Machinery & Automation

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Strat-X

This innovation is potentially useful for scientific experiments at the edge of space or autonomous environmental monitoring in extreme conditions. John F. Kennedy Space Center, Florida Experiments in space can be expensive and infrequent, but Earth’s upper atmosphere is accessible via large scientific balloons, and can be used to address many of the same fundamental questions. Scientific balloons are made of a thin polyethylene film inflated with helium, and can carry atmospheric sampling instruments on a gondola suspended underneath the balloon that eventually is returned to the surface on a parachute. For stratospheric flights between 30 and 40 km above sea level, balloons typically reach the float altitude 2-3 hours after launch, and travel in the direction of the prevailing winds.

Posted in: Briefs, Mechanical Components, Machinery & Automation

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