Tag Archives: Electronics

Blue LED breakthrough for efficient electronics

R&D – OLEDs (organic light emitting diodes) are the latest and greatest in television technology, allowing screens to be extremely thin and even curved, with little blurring of moving objects and a wider range of viewing angles. In these “RGB” displays, each pixel contains red, green and blue modules that shine at different relative brightness to produce any color desired.

But not all OLEDs are created equal.

Phosphorescent OLEDs, also known as PHOLEDs, produce light through a mechanism that is four times more efficient than fluorescent OLEDs. Green and red PHOLEDs are already used in these new TVs—as well as in Samsung and LG smartphones—but the blues are fluorescent. more> http://tinyurl.com/ng4l8uk

Moving silicon atoms in graphene with atomic precision

ScienceDaily – Richard Feynman [2, 3, 4, 5] famously posed the question in 1959: is it possible to see and manipulate individual atoms in materials?

For a time his vision seemed more science fiction than science, but starting with groundbreaking experiments in the late 1980s and more recent developments in electron microscopy instrumentation it has become scientific reality. However, damage caused by the electron beam is often an issue in such experiments.

Besides being beautiful physics, the findings open promising possibilities for atomic-scale engineering: “What makes our results truly intriguing is that the bond flip is directional — the silicon moves to take the place of the carbon atom that was hit by a probe electron,” explains Toma Susi, physicist and FWF Lise Meitner Fellow at the University of Vienna. more> http://tinyurl.com/phra9ao

Atomically thin material opens door for integrated nanophotonic circuits

R&D – A 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.

Using a laser to excite electromagnetic waves called plasmons at the surface of the wire, the researchers found that the MoS2 (molybdenum disulfide) flake at the far end of the wire generated strong light emission.

Going in the other direction, as the excited electrons relaxed, they were collected by the wire and converted back into plasmons, which emitted light of the same wavelength. more> http://tinyurl.com/pttr3h8

Can our computers continue to get smaller and more powerful?

R&D – Limits relating to time and space can be felt in practice.

The speed of light, while a very large number, limits how fast data can travel. Traveling through copper wires and silicon transistors, a signal can no longer traverse a chip in one clock cycle today.

A formula limiting parallel computation in terms of device size, communication speed and the number of available dimensions has been known for more than 20 years, but only recently has it become important now that transistors are faster than interconnections.

This is why alternatives to conventional wires are being developed, but in the meantime mathematical optimization can be used to reduce the length of wires by rearranging transistors and other components. more> http://tinyurl.com/qav9bsn

The Intricate Puzzle Known as Chip Design

By Bob Smith – These days, chip design may seem like an intricately connected jigsaw puzzle, including small, oddly shaped interlocking pieces.

Instead of static parts of a puzzle – typically, 300, 500, 750 or 1,000 pieces – spread across a coffee table, a chip under design has loads of dynamic parts located in a variety of directories or sub-directories found on various computers.

The focal point is the processor, not the center of a well-known and photographed painting or skyline, as is often the case with puzzles.

Ah, but memories are playing almost as big a role as processors, especially in chips slated for mobile multimedia devices with higher bandwidth and performance, and low-cost and power requirements.

Fortunately, things aren’t that dire any longer for engineers worried about a chip’s system yield and reliability. One clever engineering group was motivated to figure this out. It set a goal to implement a DDR memory subsystem that would deliver the highest performance and quality within a small footprint and minimal power consumption. more> http://tinyurl.com/k4evteq

Monitoring of singlet oxygen in individual cells with InGaAs camera

R&D – Singlet oxygen, the first excited state of molecular oxygen, is a highly reactive species that plays an important role in a wide range of biological processes, including cell signaling, immune response, macromolecule degradation, and elimination of neoplastic tissue during photodynamic therapy. Often, a photosensitizing process is employed to produce singlet oxygen from ground state oxygen.

The researchers at Charles Univ. utilized two detection channels (VIS and NIR) to perform real-time imaging of the very weak near-infrared phosphorescence of singlet oxygen and photosensitizer simultaneously with visible fluorescence of the photosensitizer. Their new experimental setup enables acquisition of spectral images based on singlet oxygen and photosensitizer luminescence from individual cells. more> http://tinyurl.com/kuhbuzc

Artificial retina: Physicists develop an interface to the optical nerve

R&D – Retina implants can serve as optical prostheses for blind people whose optical nerves are still intact. The implants convert incident light into electrical impulses that are transmitted to the brain via the optical nerve. There, the information is transformed into images. Although various approaches for implants exist today, the devices are often rejected by the body and the signals transmitted to the brain are generally not optimal.

In contrast to the traditionally used materials, graphene has excellent biocompatibility thanks to its great flexibility and chemical durability. With its outstanding electronic properties, graphene provides an efficient interface for communication between the retina prosthesis and nerve tissue. more> http://tinyurl.com/p5h4tdd