Researchers from The University of Zurich claim to have developed the most water-repellent clothing appropriate material.

The new coating is produced in a single step, in which silicon in a gas form condenses onto fibres to form nanofilaments.

The layer of silicone nanofilaments, which are highly chemically hydrophobic is key to the waterproof ability of the material. The spiky structure of the 40-nanometre-wide filaments strengthens that effect, creating a coating that prevents water droplets from soaking through the coating to the polyester fibres underneath. Drops of water stay as spherical balls on top of the fabric. If the material is tilted by two degrees from the horizontal, the water droplets will roll off like marbles.

Continue reading…

University of Wisconsin-Madison engineers and physicists have developed a method of measuring how strain affects thin films of silicon that could lay the foundation for faster flexible electronics.

Silicon is the industry standard semiconductor for electronic devices. Silicon thin films could be the basis for fast, flexible electronics. Researchers have long known that inducing strain into the silicon increases device speed, yet have not fully understood why.

Developed by a team of researchers led by Max Lagally, the Erwin W. Mueller and Bascom Professor of Materials Science and Engineering at UW-Madison, the new method enables the researchers to directly measure the effects of strain on the electronic structure of silicon.

Continue reading…

Scientists at Clemson University for the first time have been able to make a practical optical fiber with a silicon core.

Led by Professor John Ballato and including fiber pioneer Roger Stolen, the team of scientists was able to create this new fiber by employing the same commercial methods that are used to develop all-glass fibers, making silicon fibers viable alternatives to glass fibers for selected specialty applications. This advance ultimately should help increase efficiency and decrease power consumption in computers and other systems that integrate photonic and electronic devices.
Continue reading…

A research team from Osaka University has developed an ‘atomic pen’ that can inscribe nano-sized text on metal by manipulating individual atoms on the surface.

According to the researchers, the atomic pen is built on a previous discovery that silicon atoms at the tip of an atomic force microscope probe will interchange with the tin atoms in the surface of a semiconductor sample when in close proximity. Using this atom-interchange phenomenon, the researchers were able to arrange individual silicon atoms one by one on a semiconductor surface to spell out the letters ‘Si’. The writing process, which took about an hour and a half to complete, was conducted at room temperature.

Continue reading…

Semiconductor silicon and ferromagnet iron are cornerstones of modern technology, used in everything from computers to electric motors. An international group of scientists are reported to have combined these elements with a small amount of another common metal, manganese, to create a new material which is neither a magnet nor an ordinary semiconductor.

The new material exists in a quantum halfway house between magnet and semiconductor. The research demonstrates, for the first time, a simple recipe for reaching this halfway house, whilst also suggesting new mechanisms for controlling electrical currents and magnetism in semiconductor devices. According to an article published in the August 21st edition of the journal Nature, a small magnetic field can be used to switch ordinary semiconducting behaviour (such as that seen in the electronic-grade silicon which is used to make transistors) back on.

Continue reading…

Technology inspired by the human eye could be used to produce improved photographic images with a wider field of view.

Researchers from Northwestern University’s McCormick School of Engineering and Mechanical Engineering, teamed up with the University of Illinois, Urbana-Champaign, to create an array of silicon detectors and electronics that can be conformed to a curved surface. Like the human eye, the curved surface can then act as the focal plane array of the camera, which captures the image.

On a normal camera, such electronics must lie on a straight surface, and the camera’s complex system of lenses must reflect an image several times before it can reflect on the right spots on the focal plane.

Yonggang Huang, Northwestern University, explained: “The advantages of curved detector surface imaging have been understood by optics designers for a long time, and by biologists for an even longer time. That’s how the human eye works – using the curved surface at the back of the eye to capture the image.”

But exactly how to place those electronics on a curved surface to yield working cameras has stumped scientists, despite many different attempts over the last 20 years. The electronics lie on silicone wafers, which can only be compressed one per cent before they break and fail.

Continue reading…

Sanyo Electric’s proprietary solar cell, the ‘heterojunction’ with intrinsic thin layer (HIT), has achieved a cell conversion efficiency of 22.3 per cent.

The latest conversion efficiency is an official record that was measured by Japan’s National Institute of Advanced Industrial Science and Technology (AIST). The cell measures 100.5cm2. It has a short-circuit current of 3.909A, an open-circuit voltage of 0.725V and a fill factor of 79.1 per cent. The maximum power per cell is 2.242W.

According to Sanyo, two key points improved the performance of the latest cell. In a HIT solar cell composed of a crystalline silicon layer sandwiched by amorphous silicon layers, the company improved the technology to wash the surface of the crystalline silicon layer prior to the formation of the amorphous silicon layers. The company also optimised the size and the shape of irreguarlities on the cell surface, which are provided to prevent reflection.

The company aims to enhance the cell conversion efficiency to 23 per cent at the research level, and to 22 per cent or higher at the mass production level by fiscal 2010.

Researchers from the Universidade Nova de Lisboa, have developed a Field Effect Transistor (FET) with a paper interstrate layer.

In a new approach, a common sheet of paper was used as the dielectric layer or oxide FETs. The researchers fabricated the devices on both sides of the paper sheet. This makes it act simultaneously as the electric insulator and as the substrate.

Electric characterisation of devices showed that the hybrid FETs performance outpace those of amorphous silicon TFTs, and rival the oxide thin film transistors (TFTs) produced on glass or crystalline silicon substrates. The results suggest promising new disposable electronics such as paper display, smart labels, RFID tags and bio-applications.

A collaboration between Matsushita Electric Works and Tokyo University of Agriculture and Technology’s Graduate School of Engineering, has produced a light emitting device prototype that generates visible light by discharging electrons from a silicon device measuring 5nm or smaller into xenon gas.

The light emitting device doesn’t use an electric discharge, and so the luminance efficiency of the light can be easily enhanced.

The prototype version generates high energy electrons by applying a voltage to a ‘nanosilicon electron source’. Silicon discharges electrons when processed on the nanoscale and the prototype uses this property.

The electrons generated are discharged into xenon gas to excite the xenon molecules, which produces vacuum ultraviolet light with a wavelength of 200nm or less. The vacuum ultraviolet light collides with phosphor to be converted into visible light.

This technology is expected to find applications in high-efficiency, high-luminance lighting equipment.

A new method of sorting single-walled carbon nanotubes (SWNTs) according to their chirality, could help solve a long standing problem in the fabrication of nanotube-based electronics.

A SWNT can behave as either a metal or a semiconductor, depending on the spatial arrangement of its carbon atoms, or chirality. SWNTs are produced as a mixture of both types, however, these do not work well together and need to be separated before use.

While number of methods have been devised to separate the two types of SWNTs, none have proven practical for large scale applications.

Continue reading…

Surrey Nanosystems is to supply Ludwig-Maximilians University (LMU) with an advanced spluttering tool, to aid its research into the fabrication of hybrid solar cells.

The tool will be used by researchers in LMU’s Department of Physics and Centre for NanoScience, to develop production techniques that utilise precisely ordered nanowire structures as templates for organic material.

Compared with conventional silicon-based solar energy systems, such new generations of hybrid solar cells have the potential to dramatically lower costs, and provide ‘free’ power for consumer electronics products. By building arrays of organic solar cells on a low-resistance nanowire interconnection substrate, LMU expects to increase the efficiency of the energy conversion process.

A high-performance, low-power silicon nanoscale sensor is being developed by engineers from The University of Southampton’s School of Electronics and Computer Science as part of a three-year European FP7-funded NEMSIC (Nano-electro-mechanical-system-integrated-circuits) project.

Project leader Professor Hiroshi Mizuta, and his team at ECS will co-integrate single-electron transistors (SETs) and nano-electro-mechanical systems (NEMS) on a single silicon technology platform to create a small, sensitve sensor with low-power consumption.

Continue reading…

Researchers have produced a novel memory device set to rival transistor-switched silicon-based memory.

Conventional memory chips in electronic devices are made up of transistors, resistors and capacitors built in layers on a silicon wafer through a photolithographic process, during which precise patterns are etched on the silicon to form the chip. Today’s technology allows several million transistors to be built on a piece of silicon the size of a pinhead, but many researchers believe this form of memory has been pushed to its limits.

Researchers have been trying to create electromechanically driven switches small enough to rival transistor-switched silicon-based memory. Unlike transistors, electromechanically driven switches contain moving parts. Not only do electromechanical devices have excellent ON-OFF rations and fast switching characteristics, but the physical separation between the switch and capacitor in such devices means the data leakage problem is significantly reduced. However, until now, the technology has not been a viable alternative to silicon-based arrangements because it involved larger cells and more complex fabrication processes.

Professor Gehan Amaratunga and a team of international researchers have remedied these drawbacks by creating a novel nanoelectromechanical (NEM) switched capacitor based in vertically aligned multi-walled carbon nanotubes (CNTs).

Continue reading…