Thermal considerations are rapidly becoming one of the most serious design constraints in microelectronics, especially on submicron scale lengths. A study by researchers from the Univ. of Illinois at Urbana-Champaign has shown that standard thermal models will lead to the wrong answer in a 3-D heat-transfer problem if the dimensions of the heating element are on the order of one micron or smaller.
Blue organic light-emitting diodes (OLEDs) are one of a trio of colors used in OLED displays such as smartphone screens and high-end TVs. In a step that could lead to longer battery life in smartphones and lower power consumption for large-screen televisions, researchers at the Univ. of Michigan have extended the lifetime of blue organic light emitting diodes by a factor of 10.
Princeton Univ. researchers have developed a new method to increase the power and clarity of light-emitting diodes (LEDs). Using a new nanoscale structure made from flexible carbon-based sheet, the researchers increased the brightness and efficiency of LEDs made of organic materials by 57%.
As tech company LG demonstrated this summer with the unveiling of its 18-in flexible screen, the next generation of roll-up displays is tantalizingly close. Researchers are now reporting a new, inexpensive and simple way to make transparent, flexible transistors that could help bring roll-up smartphones with see-through displays and other bendable gadgets to consumers in just a few years.
An international team of physicists has shown that information stored in the nuclear spins of hydrogen isotopes in an organic light-emitting diode (LED) or organic LED can be read out by measuring the electrical current through the device. Unlike previous schemes that only work at ultracold temperatures, this is the first to operate at room temperature, and could be used to create extremely dense and highly energy-efficient memory devices.
Donald Sadoway and his colleagues at the Massachusetts Institute of Technology have already started a company to produce electrical-grid-scale liquid batteries, whose layers of molten material automatically separate due to their differing densities. But a newly developed formula substitutes different metals for the molten layers. The new formula allows the battery to work at a much lower temperature.
Univ. of Minnesota electrical engineering researchers have developed a unique nanoscale device that for the first time demonstrates mechanical transportation of light. The tiny device is just .7 micrometers by 50 micrometers and works almost like a seesaw. On each side of the “seesaw benches,” researchers etched an array of holes, called photonic crystal cavities. These cavities capture photons that streamed from a nearby source.
Some smartphones are starting to incorporate 3-D gesture sensing based on cameras, but cameras consume significant battery power and require a clear view of the user’s hands. Univ. of Washington engineers have developed a new form of low-power wireless sensing technology that could soon contribute to gesture control by letting users “train” their smartphones to recognize and respond to specific hand gestures near the phone.
A collaboration between scientists in the Univ. of Chicago’s chemistry department, the Institute for Molecular Engineering and Argonne National Laboratory has produced the highest-ever recorded efficiency for solar cells made of two types of polymers and fulllerene. Researchers identified a new polymer that improved the efficiency of solar cells and also determined the method by which the polymer improved the cells’ efficiency.
Faster, smaller, greener computers, capable of processing information up to 1,000 times faster than currently available models, could be made possible by replacing silicon with materials that can switch back and forth between different electrical states. Recent research in the U.K. show that these phase-change materials have promise in new processors made with chalcogenide glass.
For decades, the power conversion efficiency of organic solar cells was hampered by the drawbacks of commonly used metal electrodes, including their instability and susceptibility to oxidation. Now for the first time, researchers at the Univ. of Massachusetts Amherst have developed a more efficient, easily processable and lightweight solar cell that can use virtually any metal for the electrode, effectively breaking the “electrode barrier.”
Imagine being able to switch out the batteries in electric cars just like you switch out batteries in a photo camera or flashlight. Engineers in California 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.
Betavoltaics, a battery technology that generates power from radiation, has been studied as an energy source since the 1950s. Now, for the first time using a water-based solution, researchers at the Univ. of Missouri have created a long-lasting and more efficient nuclear battery that could be used for many applications such as a reliable energy source in automobiles and also in complicated applications such as space flight.
An interdisciplinary development team that includes Lockheed Martin, the Air Force Research Laboratory and the Univ. of Notre Dame has demonstrated the airworthiness of a new beam control turret being developed for DARPA to give 360-degree coverage for high-energy laser weapons operating on military aircraft. An aircraft equipped with the laser has already conducted eight test flights in Michigan.
The fastest land animal on Earth, the cheetah, is able to accelerate to 60 mph in just a few seconds. As it ramps up to top speed, a cheetah pumps its legs in tandem, bounding until it reaches a full gallop. Now, researchers have developed an algorithm for bounding that they’ve successfully implemented in a fully functional robotic cheetah.
Researchers in Sweden have shown how to use sound to communicate with an artificial atom, in this case an electric circuit that obeys quantum laws. By coupling acoustic waves to the atom, they can demonstrate phenomena from quantum physics with sound taking on the role of light.
Optical circuits use light instead of electricity, making them faster and more energy-efficient than electrical systems. Scientists in Switzerland have now developed a silicon-based photonic crystal nanocavity to be used as a first building-block for photonic “transistors”. The new device requires record low energy to operate.
A team of researchers has discovered a way to cool electrons to -228 C without external means and at room temperature, an advancement that could enable electronic devices to function with very little energy. The process involves passing electrons through a quantum well to cool them and keep them from heating.
For detecting cancer, manual breast exams seem low-tech compared to other methods such as MRI. But scientists are now developing an “electronic skin” that “feels” and images small lumps that fingers can miss. Knowing the size and shape of a lump could allow for earlier identification of breast cancer, which could save lives.
Rice Univ. wireless researchers have found a way to make the most of the unused UHF TV spectrum by serving up fat streams of data over wireless hotspots that could stretch for miles. In a presentation today at the Association for Computing Machinery's MobiCom 2014 conference, researchers will unveil a multiuser, multiantenna transmission scheme for UHF, a portion of the radio spectrum that is usually reserved for television broadcasts.
Technology being honed by French auto parts maker Valeo uses a dozen ultrasonic sound-wave sensors, 360-degree cameras and a laser scanner to safely park within a few centimeters of other vehicles. Then, when you're done with dinner or a business meeting, the car will return to you after another swipe of the thumb.
Engineers have created a shape-changing "soft" robot that can tread over a variety of adverse environmental conditions including snow, puddles of water, flames, and the crushing force of being run over by an automobile. The pneumatically powered, fully untethered robot was enabled by the careful selection of materials and composites, including silicone elastomer.
A flexible display incorporating graphene in its pixels’ electronics has been successfully demonstrated by the Cambridge Graphene Centre and Plastic Logic. The new prototype is an active matrix electrophoretic display, similar to the screens used in today’s e-readers, except it is made of flexible plastic instead of glass. This advance marks the first time graphene has been used in a transistor-based flexible device.
A team of U.S. and Swiss researchers have built a new basic model circuit consisting of a silver nanowire and a single-layer flake of molybdenum disulfide. This new combination of materials can efficiently guide electricity and light along the same tiny wire, a finding that could be a step towards building computer chips capable of transporting digital information at the speed of light.
A centuries-old clock built for a king is the inspiration for a group of computer scientists and electrical engineers who hope to harvest power from the air. The clock, powered by changes in temperature and atmospheric pressure, was invented in the early 17th century by a Dutch builder. Three centuries later, Swiss engineer Jean Leon Reutter built on that idea and created the Atmos mechanical clock that can run for years.
The most familiar photovoltaic (PV) designs use rigid layers of silicon crystal, but recently inexpensive organic semiconductor materials have also been used successfully. At this time, organic PV devices are hindered by low efficiency, in part because quantifying their electrical properties is a challenge. Researchers have now developed a method that allows the prediction of the current density-voltage curve of a photovoltaic device.
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