Electronics & Computers

Researchers Control Surface Tension of Liquid Metals

Researchers from North Carolina State University have developed a technique for controlling the surface tension of liquid metals by applying very low voltages, opening the door to a new generation of reconfigurable electronic circuits, antennas and other technologies. The technique hinges on the fact that the oxide “skin” of the metal – which can be deposited or removed – acts as a surfactant, lowering the surface tension between the metal and the surrounding fluid.The researchers used a liquid metal alloy of gallium and indium. In base, the bare alloy has a remarkably high surface tension of about 500 millinewtons (mN)/meter, which causes the metal to bead up into a spherical blob. “But we discovered that applying a small, positive charge – less than 1 volt – causes an electrochemical reaction that creates an oxide layer on the surface of the metal, dramatically lowering the surface tension from 500 mN/meter to around 2 mN/meter,” says Dr. Michael Dickey, an associate professor of chemical and biomolecular engineering at NC State and senior author of a paper describing the work. “This change allows the liquid metal to spread out like a pancake, due to gravity.”The researchers also showed that the change in surface tension is reversible. If researchers flip the polarity of the charge from positive to negative, the oxide is eliminated and high surface tension is restored.  The surface tension can be tuned between these two extremes by varying the voltage in small steps.SourceAlso: Learn about Gradient Metal Alloys Fabricated Using Additive Manufacturing.

Posted in: Electronics & Computers, Electronics, Power Management, Materials, Metals, RF & Microwave Electronics, Antennas, News

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Engineers Prepare Battery Module Swapping Approach for Electric Cars

Imagine being able to switch out the batteries in electric cars just like you switch out batteries in a photo camera or flashlight. A team of engineers at the University of California, San Diego, are trying to accomplish just that, in partnership with a local San Diego engineering company.Rather than swapping out the whole battery, which is cumbersome and requires large, heavy equipment, engineers plan to swap out and recharge smaller units within the battery, known as modules.Swapping battery modules could also have far-reaching implications for mobile and decentralized electrical energy storage systems such as solar backup and portable generators. The technology can make energy storage more configurable, promote safety, simplify maintenance and eventually eliminate the use of fossil fuels for these applications.Engineers not only believe that their approach is viable, but also plan to prove it. They will embark on a cross-country trip with a car powered by the removable, rechargeable M-BEAM, or Modular Battery Exchange and Active Management, battery modules.  They plan to drive from coast to coast only taking breaks that are a few minutes long to swap out the modules that will be recharged in a chase vehicle. They believe they can drive from San Diego to the coast of South Carolina less than 60 hours — without going over the speed limit.SourceAlso: Learn about a Full-Cell Evaluation/Screening Technique for New Battery Chemistries.

Posted in: Batteries, Electronics & Computers, Power Management, Solar Power, Renewable Energy, Energy, News, Automotive

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Finding the Right Manufacturer for Your Design

To receive a quality PCB, you need an efficient design and a manufacturer capable of producing it. This paper will examine the challenges and best practices associated with matching your design requirements to a manufacturer's capabilities.

Posted in: Electronics & Computers, White Papers

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Dust Removal from Solar Cells

This system is easily integrated with current solar cell panel designs. John H. Glenn Research Center, Cleveland, Ohio Photovoltaic cell arrays are used on robotic rovers on the Mars surface, but dust accumulation on the surface of the solar cells reduces their exposure to light radiation and thus degrades their performance. Dust that accumulates without being removed limits the life of the rover’s power systems. Similarly, terrestrial solar arrays suffer from dust accumulation, especially when located in desert areas, which reduces their effectiveness. Technologies for re moval of the dust or preventing it from settling have been proposed and are being researched, but none were yet implemented on the rovers. These techniques include mechanical means, blowing stored gas, blowing pumped gas, electrically charging the surface, repelling the dust, and other techniques.

Posted in: Electronics & Computers, Briefs

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Minimally Obstructed Communication via Acoustic Modems in Fluid-Filled Pipes

This technology can be used in the oil industry, as well as in various underwater operations. NASA’s Jet Propulsion Laboratory, Pasadena, California An acoustic modem that uses a separate phased-array transmitter and receiver has been conceived that allows the communication of high-frequency acoustic waves sideways to the transducer along the fluid-filled pipe. The transducer allows directing waves between the transmitter and the receiver with potentially minimal interferences with the piping walls. In addition, another method of directly sending communication signals up- and down-hole has been conceived that uses angled piezoelectric ring transducers.

Posted in: Electronics & Computers, Briefs

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Biofeedback System for Optimal Athletic Performance

Langley Research Center, Hampton, Virginia ZONE (Zeroing Out Negative Effects) is a method of biofeedback training for optimal athletic performance. ZONE is designed to improve athletes’ responses to stress, anxiety, and loss of concentration during competition. In the training environment, when the user successfully attains an optimal target state of psychophysiological functioning, the technology informs and/or rewards the user through real-time physical changes in the athletic equipment. For example, in the training setting, a golfer can work toward optimal concentration in the act of putting, leading to improved performance in real situations.

Posted in: Electronics & Computers, Briefs

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Methods for Clock and Reset Synchronization in a CMOS Integrated Circuit

These methods ensure fault-free operation in high-integrity systems. Lyndon B. Johnson Space Center, Houston, Texas In high-integrity systems, a method of assuring integrity called a self-checking pair is employed. A self-checking pair is a logical grouping of two of the same devices performing the same operation and cross-checking each other to ensure correct operation. In this manner, a single fault on one will be detected by its partner, and the appropriate action can be taken to both recover the fault and ensure the fault does not propagate.

Posted in: Electronics & Computers, Briefs

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