A team of scientists from the University of York, the Helmholtz-Zentrum Berlin (HZB) Germany, and Radboud University Nijmegen, the Netherlands, have developed a new class of magnetic material which flips magnetic state when zapped by an ultra fast laser pulse. This should pave the way to mass storage devices with improved performance and power efficiency compared to current day technology.
The new material demonstrates the use of a synthetic ferrimagnet comprising a sandwich of two ferromagnetic materials and a non-magnetic spacer layer. The spacer layer engineers the coupling between the two ferromagnets so that they align opposite one another. When subjected to an ultrafast laser pulse, this structure spontaneously switches its magnetic state representing writing a single bit of data. [via]
A New Class of Magnetic Material - [Link]
by Rick Robinson:
A research collaboration consisting of IHP-Innovations for High Performance Microelectronics in Germany and the Georgia Institute of Technology has demonstrated the world’s fastest silicon-based device to date. The investigators operated a silicon-germanium (SiGe) transistor at 798 gigahertz (GHz) fMAX, exceeding the previous speed record for silicon-germanium chips by about 200 GHz.
Although these operating speeds were achieved at extremely cold temperatures, the research suggests that record speeds at room temperature aren’t far off, said professor John D. Cressler, who led the research for Georgia Tech. Information about the research was published in February of 2014, by IEEE Electron Device Letters.
Silicon-Germanium Chip Sets New Speed Record - [Link]
Researchers have developed the technology for a catheter-based device that would provide forward-looking, real-time, three-dimensional imaging from inside the heart, coronary arteries and peripheral blood vessels. With its volumetric imaging, the new device could better guide surgeons working in the heart, and potentially allow more of patients’ clogged arteries to be cleared without major surgery.
The device integrates ultrasound transducers with processing electronics on a single 1.4 millimeter silicon chip. On-chip processing of signals allows data from more than a hundred elements on the device to be transmitted using just 13 tiny cables, permitting it to easily travel through circuitous blood vessels. The forward-looking images produced by the device would provide significantly more information than existing cross-sectional ultrasound.
Single Chip Device to Provide Real-Time 3-D Images from Inside the Heart and Blood Vessels - [Link]
Device stores twice the energy of microbatteries currently used in transmitters. By Tom Rickey:
RICHLAND, Wash. – Scientists have created a microbattery that packs twice the energy compared to current microbatteries used to monitor the movements of salmon through rivers in the Pacific Northwest and around the world.
The battery, a cylinder just slightly larger than a long grain of rice, is certainly not the world’s smallest battery, as engineers have created batteries far tinier than the width of a human hair. But those smaller batteries don’t hold enough energy to power acoustic fish tags. The new battery is small enough to be injected into an organism and holds much more energy than similar-sized batteries.
A battery small enough to be injected, energetic enough to track salmon - [Link]
A research team from National Taiwan University, National Taipei University of Technology and Chang Gung University have described how they developed a free-swimming remote-controlled bare die at the IEEE International Solid-State circuits Conference (ISSCC) in San Francisco. The 21.2 mm square die made by TSMC using a 0.35 µm process, is able to travel at 0.3 mm/s submerged in a liquid. A similar device was presented at the ISSCC in 2012, which used Lorentz forces for propulsion. This design however uses electrodes along the four edges of the chip to generate bubbles as a product of electrolysis. [via]
A Free-Swimming Chip - [Link]
In a paper published in Nature Communications researchers at IBM describe how they have built a silicon-based receiver chip incorporating GFETs or Graphene Field Effect Transistors (the purple structure in the photo) into the circuit. The multi-stage receiver integrated circuit consists of 3 graphene transistors, 4 inductors, 2 capacitors, and 2 resistors.
“This is the first time that someone has shown graphene devices and circuits to perform modern wireless communication functions comparable to silicon technology,”
said Supratik Guha, Director of Physical Sciences at IBM Research. In a test the team successfully used the graphene-based receiver to process a digital transmission on 4.3GHz. The binary sequence received was 01001001 01000010 01001101, which represents ASCII coding of the letters IBM.
IBM Chip uses Graphene FETs - [Link]
Researchers from several institutions in the U.S. and one from China have together developed a piezoelectric device that when implanted in the body onto a constantly moving organ is able to produce enough electricity to run a pacemaker or other implantable device. In their paper published in Proceedings of the National Academy of Sciences, the team describes the nature of their device and how it might be used in the future.
Currently, when the battery inside a device such as a pacemaker runs out of power, patients must undergo surgery to have it replaced. Several devices that take advantage of the body’s natural parts have been devised to allow for the creation of electricity internally so that implantable devices can run for a lifetime, preventing the need for additional surgery. Most such devices have been too small to actually charge a real device, however, as they are very much still in the research stage. In this new effort, the research team takes the idea further by creating miniature power plants that are large enough to power real implantable devices.
Team builds implantable piezoelectric nanoribbon devices strong enough to power pacemaker - [Link]
A research team at Virginia Tech has produced a low-cost rechargeable battery that runs on sugar. They are not the first in the field to develop a sugar battery but the energy density of their design shows an order of magnitude improvement over existing sugar-based battery technology.
The findings from Y.H. Percival Zhang, an associate professor of biological systems engineering in the College of Agriculture and Life Sciences and the College of Engineering, were published in the journal Nature Communications. According to Zhang “Sugar is a perfect energy storage compound in nature, so it’s only logical that we try to harness this natural power in an environmentally friendly way to produce a battery”. [via]
Battery Recharging… One Lump or Two? - [Link]
Contactless charging of mobile devices is more convenient than fiddling around with power adapters, plugs and cables but the transmit and receive coils need to be in close physical contact otherwise power transfer losses become significant. A team of researchers in Duke’s Pratt School of Engineering working with the Toyota Research Institute of North America have succeeded in creating an array of hollow cubes which act as a lens for low-frequency magnetic fields.
The lens is made up of cells with copper coils etched onto their walls. The geometry of these coils and their repeating nature form a metamaterial that interacts with magnetic fields in such a way that the transmitted fields become confined into a narrow cone where the power intensity is much higher than that of an unfocussed pattern.
A Lens for Magnetic Fields - [Link]
The weak link in electric vehicle technology is the method of energy storage and renewal, making the vehicles impractical for long distance use. The majority of today’s electric vehicles use rechargeable lithium-ion batteries which still have a relatively poor energy density compared to conventional fossil fuels and require lengthy recharge cycles. A promising alternative battery chemistry is the lithium-sulfur battery. It can store as much as four times more energy per mass than lithium-ion batteries.
Unfortunately reactions at the battery’s sulfur-containing cathode form molecules called polysulfides that dissolve into the battery’s electrolyte. The dissolved sulfur eventually develops into a thin film called a solid-state electrolyte interface layer which coats the lithium-containing anode making the battery unusable after only 100 charge/discharge cycles.
Researchers at the US Department of Energy’s Pacific Northwest National Laboratory have succeeded in quadrupling the useful number of charge/discharge cycles. They have developed a graphite shield which moves the sulfur side reactions away from the anode’s lithium surface, preventing it from growing the debilitating interference layer. The new hybrid anode combines graphite from lithium-ion batteries with lithium from conventional lithium-sulfur batteries.
Graphite Boosts Battery Life - [Link]