Mechanical & Fluid Systems

Ultrasonic/Sonic Jackhammer

Advantages include low noise, low vibration, and low average power demand. An ultrasonic/sonic jackhammer (USJ) is the latest in a series of related devices, the first of which were reported in “Ultrasonic/Sonic Drill/Corers With Integrated Sensors” (NPO-20856), NASA Tech Briefs, Vol. 25, No. 1 (January 2003), page 38. Each of these devices cuts into a brittle material by means of hammering and chiseling actions of a tool bit excited with a combination of ultrasonic and sonic vibrations. A small-scale prototype of the USJ has been demonstrated. A fully developed, full-scale version of the USJ would be used for cutting through concrete, rocks, hard asphalt, and other materials to which conventional pneumatic jackhammers are applied, but the USJ would offer several advantages over conventional pneumatic jackhammers, as discussed below.

Posted in: Briefs, TSP, Mechanical Components

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Vortobots

Vortex-generating microscopic robots would move in swarms. The term “vortobots” denotes proposed swimming robots that would have dimensions as small as micrometers or even nanometers and that would move in swarms through fluids by generating and exploiting vortices in a cooperative manner. Vortobots were conceived as means of exploring confined or otherwise inaccessible fluid environments: they are expected to be especially attractive for biomedical uses like examining the interiors of blood vessels.

Posted in: Briefs, TSP, Mechanical Components

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Two SMA-Actuated Miniature Mechanisms

These mechanisms represent two different approaches to latch/release operation. The figures depict two miniature mechanisms actuated by strips made of shape-memory alloy (SMA). A typical SMA is a nickel-titanium alloy known by the trade name “Flexinol” or “Nitinol.” In preparation for a typical application, a suitably sized and shaped piece of an SMA is deformed by a predetermined amount at the lower of two operating temperatures, then mounted in a mechanism. When stroking of the mechanism in one direction is desired, the piece of SMA is heated above a transition temperature to make it return to the “remembered” undeformed state. When stroking of the mechanism in the opposite direction is desired, the SMA is cooled below the transition temperature to make it return to the deformed state.

Posted in: Briefs, Mechanical Components

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Piezo-Operated Shutter Mechanism Moves 1.5 cm

This shutter is designed for use as part of an atomic clock. The figure shows parts of a shutter mechanism designed to satisfy a number of requirements specific to its original intended application as a component of an atomic clock to be flown in outer space. The mechanism may also be suitable for use in laboratory and industrial vacuum systems on Earth for which there are similar requirements. The requirements include the following:

Posted in: Briefs, TSP, Mechanical Components

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Temperature-Controlled Clamping and Releasing Mechanism

A report describes the development of a mechanism that automatically clamps upon warming and releases upon cooling between temperature limits of 180 K and 293 K.

Posted in: Briefs, TSP, Mechanical Components

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Fastener Starter

This tool is superior to prior screw and nut starters. The Fastener Starter is a creative solution to prevent the loss of small fasteners during their installation. This is the only currently available tool that can firmly grip and hold a single screw, bolt, nut, washer, spacer, or any combination of these parts. Other commercially available fastener starters are unable to accommodate a variety of parts simultaneously. The Fastener Starter is a more capable and easier tool to use than prior tools. Its compact size allows it to be used effectively in cramped, difficult-to-see locations. Its design also allows it to be used with or without handles and extenders in other difficult-to-reach locations. It provides better protection against cross threading and loss of fasteners and associated parts. The Fastener Starter is non-magnetic and does not off-gas, thus meeting flight hardware requirements.

Posted in: Briefs, Mechanical Components

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Nanoactuators Based on Electrostatic Forces on Dielectrics

Large force-to-mass ratios could be achieved at the nanoscale. Nanoactuators of a proposed type would exploit the forces exerted by electric fields on dielectric materials. As used here, “nanoactuators” includes motors, manipulators, and other active mechanisms that have dimensions of the order of nanometers and/or are designed to manipulate objects that have dimensions of the order of nanometers.

Posted in: Briefs, TSP, Mechanical Components

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