New Silicon Memory Chip May Offer Super-Fast Memory

The first purely silicon oxide-based 'Resistive RAM' memory chip that can operate in ambient conditions -- opening up the possibility of new super-fast memory -- has been developed by researchers at UCL.

Resistive RAM (or 'ReRAM') memory chips are based on materials, most often oxides of metals, whose electrical resistance changes when a voltage is applied -- and they "remember" this change even when the power is turned off.

ReRAM chips promise significantly greater memory storage than current technology, such as the Flash memory used on USB sticks, and require much less energy and space.

The UCL team have developed a novel structure composed of silicon oxide, described in a recent paper in the Journal of Applied Physics, which performs the switch in resistance much more efficiently than has been previously achieved. In their material, the arrangement of the silicon atoms changes to form filaments of silicon within the solid silicon oxide, which are less resistive. The presence or absence of these filaments represents a 'switch' from one state to another.

Unlike other silicon oxide chips currently in development, the UCL chip does not require a vacuum to work, and is therefore potentially cheaper and more durable. The design also raises the possibility of transparent memory chips for use in touch screens and mobile devices.

The team have been backed by UCLB, UCL's technology transfer company, and have recently filed a patent on their device. Discussions are ongoing with a number of leading semiconductor companies.

Dr Tony Kenyon, UCL Electronic and Electrical Engineering, said: "Our ReRAM memory chips need just a thousandth of the energy and are around a hundred times faster than standard Flash memory chips. The fact that the device can operate in ambient conditions and has a continuously variable resistance opens up a huge range of potential applications.

"We are also working on making a quartz device with a view to developing transparent electronics."

For added flexibility, the UCL devices can also be designed to have a continuously variable resistance that depends on the last voltage that was applied. This is an important property that allows the device to mimic how neurons in the brain function. Devices that operate in this way are sometimes known as 'memristors'.

This technology is currently of enormous interest, with the first practical memristor, based on titanium dioxide, demonstrated in just 2008. The development of a silicon oxide memristor is a huge step forward because of the potential for its incorporation into silicon chips.

The team's new ReRAM technology was discovered by accident whilst engineers at UCL were working on using the silicon oxide material to produce silicon-based LEDs. During the course of the project, researchers noticed that their devices appeared to be unstable.

UCL PhD student, Adnan Mehonic, was asked to look specifically at the material's electrical properties. He discovered that the material wasn't unstable at all, but flipped between various conducting and non-conducting states very predictably.

Adnan Mehonic, also from the UCL Department of Electronic and Electrical Engineering, said: "My work revealed that a material we had been looking at for some time could in fact be made into a memristor.

"The potential for this material is huge. During proof of concept development we have shown we can programme the chips using the cycle between two or more states of conductivity. We're very excited that our devices may be an important step towards new silicon memory chips."

The technology has promising applications beyond memory storage. The team are also exploring using the resistance properties of their material not just for use in memory but also as a computer processor.

The work was funded by the Engineering and Physical Sciences Research Council.

Source- http://www.sciencedaily.com

Li-Fi INSTEAD OF Wi-Fi?

"DATA TRANSMISSION THROUGH VISIBLE LIGHT POSSIBLE, says researchers"

Many of us are familiar with Wi-Fi technology and its impact in our daily lives. We cannot survive without it. Wi-Fi is being used everywhere like in repair shops, educational institutes, computer shops, offices. We have become quite dependent upon this technology that we can hardly imagine our life without it.

Wi-Fi technology can cover an entire home and it is band limited to 50-100 megabits per second today using IEEE802.11n standard. This is a good standard to use current services provided by internet like browsing and moving larger data files like softwares, HD movies, video games, music libraries etc. It may be very useful in today’s life but it may not be that efficient in future where we have a gesture recognition technology coming.

So here comes in the new technology names as VISIBLE LIGHT COMMUNICATION or simply VLC. It is more frequently referred to as Li-Fi(Light Fidelity).

This emerging new technology offers optical wireless communication by using visible light. An additional opportunity is arising by using current state-of-the-art LED lighting solutions for illumination and communication as the same time and with the same module. Hence when the LEDs are illuminating, their secondary duty will be to communicate data onto lighting system. This will be relevant in the indoor systems where the light will be fully ‘on’.

The premise behind VLC is that since light is always on and we have reflections everywhere communications can ride along for nearly free. The VLC technology include giga-speed technology, optical mobility technologies, navigation, precision location and gesture recognition technology.

For giga-speed technology, the Li-Fi Consortium defined GigaDock, GigaBeam, GigaShower, Giga Spot and GigaMIMO models to address different user scenarios for wireless indoor and indoor like data transfers. While GIgaDock is a wireless docking solution including wireless charging for smartphones, tablets or notebooks, with speeds upto 10Gbps, the GigaBeam model is a point to point data link for kiosk applications or portable-to-portable data exchanges. Thus a two hour full HD movie, whose size can be imagines around 5GB, can be transferred from one device to other in merely 4 seconds!

First applications of Li-Fi have already been put to use in hospitals where RF signals are a threat due to interference problems with medical equipment such as blood pumps and other life supporting instruments. The prototype of a mobile phone with an incorporated VLC system was presented by Casio in Las Vegas earlier this year. In coming years we are surely going to see more of the Li-Fi technology and more compatible products entering the market from labs.