Special Coverage

Soft Robot “Walks” on Any Terrain
Defense Advanced Research Projects Agency
Using Microwaves to Produce High-Quality Graphene
Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space
Converting from Hydraulic Cylinders to Electric Actuators
Automating Optimization and Design Tasks Across Disciplines

Compact Dielectric-Rod White-Light Delay Lines

Achievable group delays would be limited only by optical losses in materials.

Optical delay lines of a proposed type would be made from rods of such dielectric materials as calcium fluoride, fused silica, or sapphire. These would offer advantages over prior optical delay lines, as summarized below.

Posted in: Briefs, TSP, Physical Sciences, Fiber optics, Fiber optics, Calcium, Fluoride, Materials properties, Silicon alloys

Cell-Detection Technique for Automated Patch Clamping

Candidate cells are identified automatically within one second.

A unique and customizable machine-vision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify “good” and “bad” cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost.

Posted in: Briefs, TSP, Bio-Medical, Medical, Mathematical models, Artificial intelligence, Charge coupled devices, Imaging, Imaging and visualization, Artificial intelligence, Charge coupled devices, Imaging, Imaging and visualization, Biological sciences

Printed Flexible Solar Cells Provide Embedded Renewable Power

In the effort to produce inexpensive, easily manufactured sources of sustainable, renewable power, solar cells continue to be a major focus — particularly flexible solar cells that can be applied directly to surfaces. Flexible solar cells are nothing new, but the methods by which they are made have progressed significantly in recent years.

Posted in: Articles, Energy, Renewable Energy, Solar Power, Solar energy

Spiking Neurons for Analysis of Patterns

High-performance pattern-analysis systems could be implemented as analog VLSI circuits.

Artificial neural networks comprising spiking neurons of a novel type have been conceived as improved pattern- analysis and pattern- recognition computational systems. These neurons are represented by a mathematical model denoted the state- variable model (SVM), which among other things, exploits a computational parallelism inherent in spiking-neuron geometry. Networks of SVM neurons offer advantages of speed and computational efficiency, relative to traditional artificial neural networks. The SVM also overcomes some of the limitations of prior spiking-neuron models. There are numerous potential pattern-recognition, tracking, and data-reduction (data preprocessing) applications for these SVM neural networks on Earth and in exploration of remote planets.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Neural networks, Neural networks, Performance upgrades

Symmetric Phase-Only Filtering in Particle-Image Velocimetry

Performance is enhanced significantly with little increase in computation time.

Symmetrical phase-only filtering (SPOF) can be exploited to obtain substantial improvements in the results of data processing in particle- image velocimetry (PIV). In comparison with traditional PIV data processing, SPOF PIV data processing yields narrower and larger amplitude correlation peaks, thereby providing more-accurate velocity estimates. The higher signal-to-noise ratios associated with the higher amplitude correlation peaks afford greater robustness and reliability of processing. SPOF also affords superior performance in the presence of surface flare light and/or background light. SPOF algorithms can readily be incorporated into pre-existing algorithms used to process digitized image data in PIV, without significantly increasing processing times.

Posted in: Briefs, Information Sciences, Mathematical models, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Particulate matter (PM)

Efficient Coupler for a Bessel Beam Dispersive Element

A document discusses overcoming efficient optical coupling to high orbital momentum modes by slightly bending the taper dispersive element. This little shape distortion is not enough to scramble the modes, but it allows the use of regular, free-beam prism coupling, fiber coupling, or planar fiber on-chip coupling with, ultimately, 100 percent efficiency.

Posted in: Briefs, TSP, Physical Sciences, Architecture, Fiber optics, Architecture, Fiber optics, Performance upgrades

Attitude and Translation Control of a Solar Sail Vehicle

A report discusses the ability to control the attitude and translation degrees-of-freedom of a solar sail vehicle by changing its center of gravity. A movement of the spacecraft’s center of mass causes solar- pressure force to apply a torque to the vehicle. At the compact core of the solar-sail vehicle lies the spacecraft bus which is a large fraction of the total vehicle mass. In this concept, the bus is attached to the spacecraft by two single degree-of-freedom linear tracks. This allows relative movement of the bus in the sail plane. At the null position, the resulting solar pressure applies no torque to the vehicle. But any deviation of the bus from the null creates an offset between the spacecraft center of mass and center of solar radiation pressure, resulting in a solar-pressure torque on the vehicle which changes the vehicle attitude. Two of the three vehicle degrees of freedom can be actively controlled in this manner. The third, the roll about the sun-line, requires a low-authority vane/propulsive subsystem.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Architecture, Attitude control, Architecture, Attitude control, Solar rocket engines

Performance of 1mm² Silicon Photomultipliers

A silicon photomultiplier (SPM) is a new type of semiconductor detector that has the potential to replace the photo- multiplier tube (PMT) detector in many applications. In common with a PMT detector, the output of an SPM is an easily detectable current pulse for each detected photon and can be used in both photon counting mode and as an analogue (photocurrent) detector. However, the SPM also has a distinct advantage over PMT detectors. The photon-induced current pulse from a PMT varies greatly from photon to photon, due to the statistics of the PMT multiplication process (excess noise). In contrast, the current pulse from an SPM is identical from photon to photon. This gives the SPM a distinct advantage in photon counting applications as it allows the associated electronics to be greatly simplified. Identical pulses also mean that the SPM can resolve the number of photons in weak optical pulses, so-called photon number resolution. This is critical in a number of applications including linear-optics quantum computing.

Posted in: Articles, Semiconductors & ICs, Detectors, Semiconductors, Test equipment and instrumentation

Advanced Position Sensors to Aid NASA in Future Spaceflight

Silicon carbide-based position sensors
INPROX Technology Corp.
Boston, MA

INPROX Technology Corp. (ITC) has entered into a Space Act Agreement (SAA) with NASA’s John H. Glenn Research Center in Ohio to develop advanced silicon carbide (SiC)- based position sensors aimed at potential uses in future spaceflight, turbine engine controls, and automotive engine applications. Under this SAA, high-temperature SiC electronics from NASA will be prototyped into ITC’s proprietary linear position sensor technology platform.

Posted in: Application Briefs, Sensors, Sensors and actuators, Spacecraft guidance, Sensors and actuators, Spacecraft guidance

Simulated Models Test Design of Space Shuttles and Rocket Engines

Finite element modeling and analysis
Dynamic Concepts
Huntsville, AL

NASA tasked Dynamic Concepts (DCI) with assessing the structural dynamics of the rollout process, whereby the space shuttle orbiter, external tank, and solid rocket booster assembly is moved via a crawler transporter from the Vertical Assembly Building to the launch pad. DCI used Femap finiteelement modeling software from Siemens PLM Software (Plano, TX) to create an integrated model of all the shuttle components, and used Siemens’ NX Nastran to analyze the simulated vibration environment. The analysis helped NASA resolve issues with support structures and determine target rollout speeds that minimized potentially damaging vibration.

Posted in: Application Briefs, Motion Control, Propulsion, Simulation and modeling, Rocket engines, Reusable launch vehicles and shuttles

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