Tech Briefs

Simulation of MEMS Piezoelectric Micropump for Biomedical Applications

University of Alberta uses simulation software for multiphysics analysis. Since the advent of Micro Electro Mechanical Systems (MEMS) technology, microfabrication methods have been used to manufacture a wide range of miniature pumps. These micropumps find their greatest use in chemical and biomedical applications requiring the transport of small, accurately measured liquid quantities. When utilized in chemical applications, micropumps are often a component of a lab-on-a-chip device. Such devices are envisioned as providing for reasonably inexpensive, possibly even disposable, means to conduct laboratory experiments.

Posted in: Bio-Medical, Briefs

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Ultrasonic/Sonic Mechanisms for Drilling and Coring

These mechanisms imitate burrowing actions of gophers and crabs. Two apparatuses now under development are intended to perform a variety of deep-drilling, coring, and sensing functions for subsurface exploration of rock and soil. These are modified versions of the apparatuses described in "Ultrasonic/Sonic Drill/Corers With Integrated Sensors" (), NASA Tech Briefs, Vol. 25, No. 1 (January 2001), page 38. In comparison with the drilling equipment traditionally used in such exploration, these apparatuses weigh less and consume less power. Moreover, unlike traditional drills and corers, these apparatuses function without need for large externally applied axial forces.

Posted in: Briefs, TSP

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Advances in Thrust-Based Emergency Control of an Airplane

It should be possible to land safely after a primary-flight-control failure. Engineers at NASA's Dryden Flight Research Center have received a patent on an emergency flight-control method implemented by a propulsion-controlled aircraft (PCA) system. Utilizing the pre-existing auto-throttle and engine-pressure-ratio trim controls of the airplane, the PCA system provides pitch and roll control for landing an airplane safely without using aerodynamic control surfaces that have ceased to function because of a primary-flight- control-system failure. The installation of the PCA does not entail any changes in pre-existing engine hardware or software. [Aspects of the method and system at previous stages of development were reported in "Thrust-Control System for Emergency Control of an Airplane" (DRC-96-07), NASA Tech Briefs, Vol. 25, No. 3 (March 2001), page 68 and "Emergency Landing Using Thrust Control and Shift of Weight" (DRC-96-55), NASA Tech Briefs, Vol. 26, No. 5 (May 2002), page 58.]

Posted in: Briefs, TSP

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Active State Model for Autonomous Systems

Autonomous systems would be able to diagnose themselves and respond accordingly. The concept of the active state model (ASM) is an architecture for the development of advanced integrated fault-detection- and-isolation (FDI) systems for robotic land vehicles, pilotless aircraft, exploratory spacecraft, or other complex engineering systems that will be capable of autonomous operation. An FDI system based on the ASM concept would not only provide traditional diagnostic capabilities, but also integrate the FDI system under a unified framework and provide mechanism for sharing of information between FDI subsystems to fully assess the overall "health" of the system.

Posted in: Briefs, TSP

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Modernizing Fortran 77 Legacy Codes

The investment in established codes is preserved as modern capabilities are added. An incremental approach to modernization of scientific software written in the Fortran 77 computing language has been developed. This approach makes it possible to preserve the investment in legacy Fortran software while augmenting the software with modern capabilities to satisfy expanded requirements. This approach could be advantageous (1) in situations in which major rewriting of application programs is undesirable or impossible, or (2) as a means of transition to major rewriting.

Posted in: Briefs, TSP

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Improved Thermal-Insulation Systems for Low Temperatures

Efficient, robust insulation for soft vacuum. Improved thermal- insulation materials and structures and the techniques for manufacturing them are undergoing development for use in low-temperature applications. Examples of low- temperature equipment for which these thermal insulation systems could provide improved energy efficiency include storage tanks for cryogens, superconducting electric- power- transmission equipment, containers for transport of food and other perishable commodities, and cold boxes for low-temperature industrial processes. These systems could also be used to insulate piping used to transfer cryogens and other fluids, such as liquefied natural gas, refrigerants, chilled water, crude oil, or low-pressure steam.

Posted in: Briefs, TSP

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Simplified Waterproofing of Aerogels

Silanization is performed in a single treatment at moderate temperature and pressure. A relatively simple silanization process has been developed for waterproofing or rewaterproofing aerogels, xerogels, and aerogel/tile composites, and other, similar low-density, highly microporous materials. Such materials are potentially attractive for a variety of applications — especially for thermal-insulation panels that are required to be thin and lightweight. Unfortunately, such materials are also hydrophilic and tend to collapse after adsorbing water from the air. Hence, an effective means of waterproofing is necessary to enable practical exploitation of aerogels and the like.

Posted in: Briefs, TSP

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