MEMs

Miniature Semiconductor Diodes as Pumps and Motors

Experiments have shown that when a miniature semiconductor diode floats in an aqueous solution and an alternating electric field is applied, (1) the diode rectifies the alternating potential induced between the electrodes, and (2) the resulting pulsating DC potential gives rise to an electro-osmotic flow in the vicinity of the diode and associated force that orients the diode along the electric-field direction, and propels the diode through the water. The propulsive force on the diode is along the electricfield direction and can be toward the cathode or the anode end, depending on the precise nature of the surface charge on the diode and the chemical composition of the solution. It has been proposed to exploit this phenomenon in developing microscale and nanoscale pumps and motors for diverse purposes. The proposal is not as radical as it might first seem: Electro-osmosis in applied DC electric fields has been used to pump liquids in microfluidic devices.

Posted in: Briefs, Electronics & Computers, Semiconductor devices, Pumps
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Optical-Fiber Infrasound Sensors

Optical-fiber infrasound sensors (OFISs) are being developed for detecting acoustic pressures in the frequency range from a few millihertz to a few hertz. As explained below, these sensors were conceived to overcome some of the limitations of prior infrasound sensors based on pipe filters connected to microbarographs.

Posted in: Briefs, Photonics, Fiber optics, Sensors and actuators, Acoustics
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Study of Membrane Optics for Lightweight Space Telescopes

Astudy has been performed to establish a foundation for the analysis, design, and further development of inplane- actuated deformable membrane mirrors for lightweight spaceborne telescopes. It is envisioned that the telescopes, having typical mirror diameters of 20 m or larger, would be stowed compactly for launch and transport, then deployed in orbit around the Earth for use in surveillance of the Earth and in exploration of deep space.

Posted in: Briefs, Photonics, Mirrors, Optics, Test equipment and instrumentation
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Implantable Electrochemical Sensors for Metabolic Monitoring

Arrays of electrochemical sensors that include specially coated (as described below) gold electrodes on flexible polyimide sheets have been fabricated and tested in a continuing effort to develop biocompatible, surgically implantable electrochemical-sensor arrays for continuous measurement of concentrations of analytes that play major roles in human and animal metabolism. The effort thus far has been oriented particularly toward developing sensors for monitoring one analyte — glucose — to enable improved treatment of diabetic patients. It is planned to extend this effort to the fabrication and testing of sensors for monitoring lactate and pyruvate and, eventually, to implement the concept of a single array that contains sensors for monitoring glucose, lactate, and pyruvate.

Posted in: Briefs, Medical, Sensors and actuators, Medical, health, and wellness
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Portable Simulator for Training in Robot-Assisted Surgery

Aportable apparatus is being developed as a means of training surgeons in robot-assisted surgery, including laparoscopic and other forms of minimally invasive surgery. The apparatus can be characterized as a virtual reality system that includes not only a computer and a visual display subsystem, but also an electromechanical subsystem with which a surgeon in training can interact as though interacting with a console of the type used to control a laparoscopic, endoscopic, or other surgical robot.

Posted in: Briefs, Medical, Simulation and modeling, Surgical procedures, Robotics
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Imaging System for Characterizing Materials and Processes

Ahigh-performance digital imaging system has been assembled to provide enhanced capabilities for characterizing materials and processes. Highspeed imaging is needed for observation and analysis of such fast dynamic processes as impact fracture (including ballistically induced fracture) in advanced composite materials, dynamic deformation of materials, and hydrodynamic instabilities in jets. Because these dynamic processes occur at diverse temporal and spatial scales, there is a need for an imaging system that can operate at correspondingly diverse frame rates, spatial resolutions, and magnifications, and that is capable of recording various numbers of image frames.

Posted in: Briefs, Physical Sciences, Imaging
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Progress in Research on Bacteria-Powered Motors

Progress has been made on several fronts in research on biomotors and especially on microscopic motors powered by bacteria. The progress consists mostly of advances in the art of attaching motile bacterial cells to surfaces in specific, pre-designed microarrays.

Posted in: Briefs, Physical Sciences, Bacteria
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Fabrication of Lightweight Armored Doors for HMMWVs

A document describes a concept for fabricating lightweight armored doors for the Army’s high-mobility multipurpose wheeled vehicles (HMMWVs). Essentially, the concept is to reinforce high-hard (HH) steel armored doors used on some HMMWVs with a laminated, woven, high-tensile-strength glassfiber/ polyester-matrix composite that has performed well as armor material in previous military applications. A fabrication procedure for implementing the concept, described in the document, can be summarized as follows:

Posted in: Briefs, Manufacturing & Prototyping, Doors, Fabrication, Composite materials, Glass fibers, Steel, Military vehicles and equipment
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AFRL’s Demonstration and Science Experiments Mission

A document describes the Air Force Research Laboratory's Demonstration and Science Experiments (DSX) mission, dedicated to research needed to advance the ability to operate spacecraft in the harsh radiation environment of medium earth orbit (MEO). The DSX spacecraft, to be launched in late 2009 into an orbit ranging in altitude from 6,000 to 12,000 km, is designed to carry instruments pertinent to studies in three categories:

Posted in: Briefs, Physical Sciences, Research and development, Spacecraft
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UDE 2.0.7 and UAD2 Debug Tools for Microcontrollers

A debug tool specially tailored to support the individual features of Infineon's new scalable XC2200 microcontoller family was recently released by PLS Development Tools (San Jose, CA). Infineon used the modular components-based Universal Debug Engine (UDE) 2.0.7 and the Universal Access Device 2 (UAD2) family of units from PLS to test its first XC200 microcontrollers and for preparation of software drivers and application examples. Both the UDE 2.0.7 and the UAD2 provide unlimited support for all internal debug resources and peripheral sets of Infineon's new XC200 microcontrollers. The integrated FLASH/OTP programming function of the UDE 2.0.7 enables high speeds in the entire FLASH, but also for external devices from AMD, Intel, ATMEL, and other JEDEC-compatible FLASH memories.

Posted in: Products, Products, Electronics & Computers
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