Interested In Science?

OK, very quick post as just about purely B-E-A-utiful technology. Below is the newest prototype OLED screen from Sony, as recently (today) mentioned on GIZMODO.com.

STUNNING. At 0.01inches thick and a still impressive resolution of 960×540, it makes me, quite frankly, sick.

Read more at GIZMODO.

interestedinscience.com © 2008

Well, it has been rumoured for a while now and its properties as a potential silicon-replacement have been exhalted for several years, but it looks that finally the worlds smallest transistors will be graphene based.

In science yesterday a team at Manchester have reported the development of a transistor made of graphene only 1 atom thick (graphene is a flat molecule - the graphite in your pencil is many sheets of graphene) and 10 atoms long.

This is (pardon the magnitude-based pun) huge news!

Ever since Richard Feynman’s lectures on the potential for miniaturization of circuitry, nanoscience has been one of the (if not in fact THE) fastest growing areas of science. And this latest development is at the very frontier and epitomizes what I’m sure Prof Feynman was hinting at.

The paper can be read in full at the following link (if you have access). If you don’t there is a well written commentary here on the BBC website.

There is also a commentary (Science Perspective doi: 10.1126/science.1156936) on Graphene in the journal science through this link.

The paper from the Manchester group is cited below.

Ponomarenko, L.A., Schedin, F., Katsnelson, M.I., Yang, R., Hill, E.W., Novoselov, K.S., Geim, A.K. (2008). Chaotic Dirac Billiard in Graphene Quantum Dots. Science, 320(5874), 356-358. DOI: 10.1126/science.1154663

interestedinscience.com © 2008

Ha ha! At last some certifiable published research/progress on the flat-screen/organic electronics-printing front (sorry for that appauling intro…it’s early).

Japanese scientists have published in PNAS (see citation at bottom - next edition) a method to reliably print flat screen panels using a fancy new inkjet style printer (see also BBC News). The technique allows them to circumvent the problems of todays silicon-based flat panel printing processes which in order to obtain maximum purities and performances have yielded to higher processing temperatures, increased manufacturing costs, and thus a higher price for the consumer - exactly what plastic electronic technology is designed to help combat.

The inkjet printers are able to print dots of 1 micron (a millionth of a meter, 1×10-6m, a thousandth of a millimeter…very small!) on to a flexible organic semiconductor. Current printing techniques are limited in their abilities to replicate the resolutions achieved by silicon-based devices and other lithographic techniques for several reasons - one being surface tension of the inks. This new printing technique allows droplet volumes of less than 1 femtolitre - a millionth that which recent techniques allowed.

All in all…yes! Very happy with this development.
See citation below for full article…

Sekitani, T., Noguchi, Y., Zschieschang, U., Klauk, H., Someya, T. (2008). Organic transistors manufactured using inkjet technology with subfemtoliter accuracy. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0708340105

interestedinscience.com © 2008

As I have covered in Plastic Electronics: Explained and probably several posts about nanomaterials or plastic electronics, silicon based computer chips are approaching their physical limits of ’shrink-ability’. By this I mean the break-down of the quantum abilities of the materials once certain components of them become so small that they are unable to do what they should (namely, the gate-oxide in a silicon transistor is becoming so thin that soon electrons will be able to tunnel through and it will no longer be an insulator).

So as you can imagine, in order to keep up with the infamous Moore’s Law and maintain the linear increase of transistors-per-chip, ways to circumvent this issue have been being researched for several years, from several different directions.

One of the latest efforts to show promise is from a group of researchers in Hong Kong who have incorporated the use of carbon nanotubes instead of the copper or tungsten ‘plugs’ to interconnect the layers of silicon semiconductor. This doesn’t remove the use of silicon, but does take a stab at improving the ability of companies to make ever-smaller/powerful microchips.

Read more here at the patent application, and here at NewScientist.

interestedinscience.com © 2007

This gadget is superb. I can’t vouch for the quality of the screens produced, the resolution is stated but I wouldn’t like to even offer an opinion on them, but they look fantastic!

A friend of mine who is a bit of a computer-boff told me about the keyboard a couple of weeks ago, but I’d clean forgot about them until I was just surfing whilst waiting on a reaction to heat up

Here are the image and links to where these amazing devices can be purchased from.

http://www.artlebedev.com/everything/optimus/

It looks the part…and unfortunately will probably cost more than the computer with which you’re using it. But oh good god it’s a piece of style.

For the record I am not in the employment of the designers or sellers of this keyboard - I actually believe that these keyboards need no selling, as they sell themselves quite well I reckon!

If anyone who reads this blog has one or has ordered one, please leave a review when you’ve seen just how good it is!

interestedinscience.com © 2007

I am hugely aware of a distinct lack of postings on this site for almost a fortnight now - and I feel I can only justify this with a rather large work load in the lab, coupled with preparations for a bit of a lab redesign…so I apologise.

I am very happy to have read in the RSC Chemistry World RSS feed (click here to subscribe - it is worth it) about a new review on molecules for application in electronic circuits. A review is essentially an overview of the recent literature and developments in a specific area of a subject. They sometimes quote new work, but this is not the usual case. They are (hopefully) a thorough ‘review’ of work in the area of focus, and thus can be exceptionally useful for finding primary literature (original journal articles) and tying ideas together.

The area of molecules for use as electronic devices has been reviewed several times over, with Carroll and Gorman’s ‘The Genesis of Molecular Electronics’ and Tour’s ‘Molecular Electronics. Synthesis and Testing of Components’ being my two favourites. There hasn’t been a good one for a while though, so this recent review on the developments in molecular rectifiers and switches was a welcomed read.
Published in a recent edition of Organic and Biomolecular Chemistry, it describes the recent advances in the synthesis of potential molecular devices, with the primary focus on memory units.

Interestingly it also highlights an issue that I think is overlooked in a lot of the literature. Perhaps the main impetus for designing molecular devices was the idea of producing molecule sized devices to replace the aging macroscopic scale semiconductors and silicon computer chips that we have today, enabling, potentially, the designed and production of tiny electronic components and, perhaps one day, a tiny computer, which is no larger than a matchbox and yet has unparalled functionality. This is not the case, as is largely becoming more and more evident as the task of locating and implementing the now available devices into electronic circuits. They are just too small to be able to manipulate with today’s technologies, and any technologies that can be envisioned in the near future. What this paper discusses, admittedly only briefly, is the role these miniature electronic architectures are going to have - simply replacing their inorganic counterparts due to their not being able to be made any smaller.

Essentially this means nothing. The idea that one day a computer will just be a small lump of plastic, which connects wirelessly to an OLED screen which can be unrolled (perhaps even out of the computer/plastic block itself??) is a sci-fi notion that I think I may be alone in believing may be possible. What it means practically is that Moore’s Second Law (addressing the fact that costs will prohibit improvements in silicon-based chips before their quantum abililties could) could be side-stepped as an issue, and Intel could produce smaller and smaller chips into the next century without having to deviate from their mission statement.

But I digress.

So, the journal to get reading is Org. Biomol. Chem. 2007 5 2343 by Mayor et al. Read it, and feel free to comment on my rants here at interestedinscience.com.

interestedinscience.com © 2007

In the latest edition of the journal Science there features a report on the successful preparation of a plastic photovoltaic cell that reaches efficiencies of 6.5%, a record for this type of device. Alan Heeger and colleagues from the University of California, Santa Barbara, in collaboration with scientists from Gwangju Institute of Science and Technology, have sandwiched two polymers together around a layer of transparent titanium oxide, to create a ‘tandem cell’.

The reason the efficiency of this device is so high is that the two different polymers absorb in different regions of the solar emission spectrum i.e. electromagnetic radiation emitted from the sun, meaning they can collect more light energy. The titanium oxide layer is completely transparent to these energies of light, and thus allows the rear polymer to absorb light that isn’t absorbed by the front polymer. The titanium oxide is an integral component because of this transparency.

‘Tandem cell architectures’ have been attempted before but without this high efficiency; partly due to the two polymers absorbing the same energies of light, partly due to poor processing methods allowing the polymers to mix, but also down to the incorporation of only a semi-transparent layer sandwiched between the layers, severely inhibiting the absorption capabilities of the rear plastic film.

Schematic of the tandem cell, taken from Science 2007 317 222-225

Some scientists believe that 6.5% effective power conversion is likely beatable in the very near future, with figures closer to 10% being rumoured. This new tandem cell could herald a break-through in the technology. Due to the nature of the materials that constitute these devices, their production is cheap, with large flexible surfaces being the obvious goal.

Keep checking interestedinscience.com for any updates on this subject.

For more on this topic, see gizmodo.com or technologyreview.com

See {Science 2007 317 222-225} for the original article.

interestedinscience.com ©  2007

OK, so not directly a development in science but more good impetus for the industry and general research.

Universal Display Corporation have been awarded US$200K by the US DOE (Department of Energy) to aid their research into SOLED™ (stacked organic light emitting diodes) technology, in an attempt to produce WOLED™ technology (white OLEDs) of high efficiency. Also described by a second grant is the aim to increase the performance of their PHOLED (phosphorescent OLEDs) technology with increased size of display panel. Says President and Chief Operating Officer of UDC Steven Abramson:

“We are pleased to continue our work with the US Department of Energy to demonstrate further advancements in our white OLED technology.”

I bet they are! OLEDs are the science behind a new flat-panel screen technology that will soon take over LCD (liquid crystal display), TFT (thin film transistor) and Plasma screens.

Many scientists envision a highly flexible, paper-thin sheet of organic material which can be used in much the same way as todays TFT screens are, but which display a higher resolution for a wider viewing angle, as well as being cheaper to process. Screens made of such material are already being incorporated into consumer electronics, such as phones and PDAs, flat screen televisions and, my favourite, the Aston Martin DB9 instrumentation panel.

The science behind these screens is fascinating (I know, my thesis is partly based on it!) and the fact that such an advanced technology, only conceived at most 12 years ago, is now in full production is simply fantastic. The futuristic look and the projected low costs is a massive attraction with this technology, but nothing is as attractive as their potential power efficiencies.

Example OLED device, taken from www.mygadgetbag.com

Keep checking these pages as this is one subject I will definitely be coming back to.

interestedinscience.com ©  2007