Power Management
Researchers Control Surface Tension of Liquid Metals
Posted in Electronics & Computers, Electronics, Power Management, Materials, Metals, RF & Microwave Electronics, Antennas, News on Friday, 19 September 2014
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.

Source

Also: Learn about Gradient Metal Alloys Fabricated Using Additive Manufacturing.
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Engineers Prepare Battery Module Swapping Approach for Electric Cars
Posted in Batteries, Electronics & Computers, Power Management, Solar Power, Renewable Energy, Energy, News, Automotive on Friday, 19 September 2014
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.

Source

Also: Learn about a Full-Cell Evaluation/Screening Technique for New Battery Chemistries.
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Connecting the World with Tiny Radios
Posted in Electronic Components, Board-Level Electronics, Power Supplies, Electronics, Power Management, Medical, Patient Monitoring, Diagnostics, News, MDB on Wednesday, 17 September 2014
A Stanford University engineering team has built a radio the size of an ant that requires no batteries. The device gathers all the power it needs from the same electromagnetic waves that carry signals to its receiving antenna. Designed to compute, execute, and relay commands, the tiny wireless chip costs pennies to manufacture, making it cheap enough, they say, to become the missing link between the Internet and the connected smart gadgets envisioned in the “Internet of Things.”
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Water Splitter Runs on AAA Battery
Posted in Batteries, Electronics & Computers, Power Management, Alternative Fuels, Green Design & Manufacturing, Materials, Metals, Energy, News on Friday, 22 August 2014
Scientists at Stanford University have developed a low-cost, emissions-free device that uses an ordinary AAA battery to produce hydrogen by water electrolysis.  The battery sends an electric current through two electrodes that split liquid water into hydrogen and oxygen gas. Unlike other water splitters that use precious-metal catalysts, the electrodes in the Stanford device are made of inexpensive and abundant nickel and iron.

In addition to producing hydrogen, the novel water splitter could be used to make chlorine gas and sodium hydroxide, an important industrial chemical.

Splitting water to make hydrogen requires no fossil fuels and emits no greenhouse gases. But scientists have yet to develop an affordable, active water splitter with catalysts capable of working at industrial scales.

"It's been a constant pursuit for decades to make low-cost electrocatalysts with high activity and long durability," said Stanford University Professor Hongjie Dai. "When we found out that a nickel-based catalyst is as effective as platinum, it came as a complete surprise."

Source

Also: Learn about a Proton Exchange Membrane Fuel Cell.
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New Circuits Can Function at Temperatures Above 650°F
Posted in Electronics & Computers, Electronic Components, Board-Level Electronics, Electronics, Power Management, Aerospace, Transportation, Automotive, Semiconductors & ICs, News on Monday, 11 August 2014
Engineering researchers at the University of Arkansas have designed integrated circuits that can survive at temperatures greater than 350 degrees Celsius — or roughly 660 degrees Fahrenheit. Their work, funded by the National Science Foundation, will improve the functioning of processors, drivers, controllers and other analog and digital circuits used in power electronics, automobiles and aerospace equipment, all of which must perform at high and often extreme temperatures.
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Battery-Free Connection for 'Internet of Things'
Posted in Electronic Components, Power Supplies, Electronics, Power Management, Medical, Patient Monitoring, Diagnostics, News, MDB on Wednesday, 06 August 2014
In the not too distant "Internet of Things" reality, sensors could be embedded in everyday objects to help monitor and track everything from the safety of bridges to the health of your heart. But what’s holding this new reality back is having a way to inexpensively power and connect these devices to the Internet, say engineers at the University of Washington, Seattle.
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Designing a Pure Lithium Anode
Posted in Batteries, Electronic Components, Power Supplies, Electronics, Power Management, Medical, News, MDB on Tuesday, 05 August 2014
The race is on to design smaller, cheaper, and more efficient rechargeable batteries to meet power storage needs. Now, a team of researchers at Stanford University report that they have taken a big step toward designing a pure lithium anode, which, they say, would greatly advance current lithium ion batteries.
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