Tech Briefs

ELID Grinding of Large Aspheres

Goddard Space Flight Center, Greenbelt, Maryland This work focused on a manufacturing process to produce silicon carbide optical surfaces with low mid-spatial surface errors. Mid-spatial frequency (MSF) and high-spatial frequency (HSF) surface errors in the grinding of fast aspheres are amplified in hard ceramics like silicon carbide due to cyclic tool wear rates, vibration, and tool deformation.

Posted in: Manufacturing & Prototyping, Briefs

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Highly Aligned Electrospun Fibers and Mats

These mats have applications in fuel and solar cells, smart textiles, and in wound dressings and tissue engineering scaffolds. Langley Research Center, Hampton, Virginia A modified electrospinning apparatus has been created for spinning highly aligned polymer fibers. Fiber placement, orientation, and porosity are difficult to control using conventional electrospinning apparatus. Conventional electrospinning creates randomly oriented fibers that are well suited to nonwoven mats, but not to other applications. This new technology will broaden the range of engineering applications of electrospun materials. The apparatus provides a simple and inexpensive means of producing fibers and mats of controlled fiber diameter, porosity, and thickness.

Posted in: Manufacturing & Prototyping, Briefs

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Compact Regenerative Blower

The blower can be used to provide ventilation flow for astronauts in spacesuits, cooling for soldiers wearing body armor, or in personal cooling systems for construction work, law enforcement, or firefighting. Lyndon B. Johnson Space Center, Houston, Texas The regenerative blower provides air flow through structures or systems that have relatively high flow resistance. Specifically, the regenerative blower was designed to provide a flow of ventilation gas through a spacesuit and its portable life support system (PLSS). Since the ventilation gas is primarily oxygen, fire prevention is a critical design requirement.

Posted in: Mechanics, Mechanical Components, Briefs

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Shape-Memory-Alloy-Based Launch Lock

This low-mass, low-power lock can be activated multiple times. NASA’s Jet Propulsion Laboratory, Pasadena, California Most NASA missions require the use of a launch lock for securing moving components during the launch or securing the payload before release. A launch lock is used to prevent unwanted motion and secure the controlled components. The current launch locks are based on pyrotechnic, electromechanical or NiTi-driven pin pullers that are one-time activation mechanisms. Generally, the use of piezoelectric activation provides high-precision nanometer accuracy, but they rely on friction to generate displacement. During launch, the generated vibrations can release the normal force between the actuator components, allowing the shaft’s free motion, which could result in damage to the actuated structures or instruments. This problem is common to other linear actuators that consist of a ball screw mechanism. There are many mechanisms that require the capability of being activated multiple times, and the disclosed concept addresses this need.

Posted in: Mechanics, Mechanical Components, Briefs

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Rotary Microspine Technology

A new design improves the mobility of manportable reconnaissance robots. NASA’s Jet Propulsion Laboratory, Pasadena, California Mobility for small, man-portable reconnaissance robots in the past has been limited with regard to obstacles like curbs, stairs, and vertical walls. A previous innovation overcame these obstacles by introducing rotary microspines — sharp hooks supported by elastic elements on a wheel. In this innovation, the work has been advanced with a new microspine design that eliminates the need for elastomer materials or the inserted hook.

Posted in: Mechanical Components, Briefs

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Rotary Microspine Technology

A new design improves the mobility of man-portable reconnaissance robots. NASA’s Jet Propulsion Laboratory, Pasadena, California Mobility for small, man-portable reconnaissance robots in the past has been limited with regard to obstacles like curbs, stairs, and vertical walls. A previous innovation overcame these obstacles by introducing rotary microspines — sharp hooks supported by elastic elements on a wheel. In this innovation, the work has been advanced with a new microspine design that eliminates the need for elastomer materials or the inserted hook.

Posted in: Mechanics, Mechanical Components, Briefs

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Percussive Augmenter of Rotary Drills for Operation as a Rotary-Hammer Drill

New rotary drill bits designed for percussive or ultrasonic hammering convert rotary drills/samplers into rotary-hammering drills/samplers. NASA’s Jet Propulsion Laboratory, Pasadena, California A piezoelectrically actuated percussive bit augments rotary drills to form a rotary-hammering drill/sampler. The Percussive Augmenter of Rotary Drills (PARoD) bit has two key modalities: one with vibrating free-mass and one without. In the first modality, the bit is designed to rotate the tip and transmit the impact of a free mass, while the complete bit turns as a single unit. In the second modality, the ultrasonic hammering action from the piezoelectric stack and the rotation from a commercial drill are applied directly to the drilled object. The PARoD tool includes slots to ensure that the tip of the bit does not rotate separately from the piezoelectric actuator. The bit employs electric and mechanical slip rings to transfer electric power, as well as water (for removal of cuttings and bit cooling), while freely turning the bit. The cooling plumbing can be connected to the related fixtures on heavy-duty commercial rotary drills.

Posted in: Mechanics, Mechanical Components, Briefs

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