Archive for February 20th, 2012

RESEARCH at Stanford School of Engineering have found a way to weld together meshes of nanowires with light.

A lot of work is currently being done on nanoelectronics, and one of these is the creation of electrically conductive meshes made of metal nanowires. These meshes could one day be used in touchscreens, displays, LEDs and thin-film solar cells.

However, to create such a mesh, nanowires must be melded together in a crisscross pattern. Pressing them together or heating them damages the nanowires.

The Stanford engineers utilised plasmonics to fuse the wires using light. Plasmonics is the physics behind the interaction of light and metal in which the light flows across the surface of the metal in waves.

If two nanowires are placed to criss-cross each other, light generates Plasmon waves at the intersection, creating a hot spot. This fuses the nanowires, after which the hot spot disappears, preventing damage from residual heat.

This light-based, self-limiting, highly precise heating increases the control, speed and energy efficiency of nanoscale welding, easing the creation of nanowire meshes.

According to the researchers, the new technique could also allow mesh electrodes to be bound to flexible or transparent plastics and polymers. For example, they sprayed a solution containing silver nanowires in suspension on a plastic wrap and dried it.

Upon inspection after illumination, the spray had left an ultrathin layer of welded nanowires. The wrap was balled up, and found to maintain its electrical properties upon unwrapping. It also maintained most of its transparency.

Prior to the plasmonics approach, the plastic wrap holding the nanowires would have had to be heated to weld them together, destroying the substrate.

Welding nanowires with light

TAG:nanotechnology research and development

SAN FRANCISCO – Intel gave its first details public look into Ivy Bridge, the first processors to use its 22 nm tri-gate technology. Intel plans at least four major variants of the chip which packs 1.4 billion transistors into 160mm2 in its largest version.

Ivy Bridge packs 20 channels of PCI Express Gen 3 interconnect and a Displayport controller, Intel’s first chip to integrate PCIe. The move marks one small step into the long term quest of what an Intel executive called terascale-class clients.

The first Ivy Bridge chip targets a range of desktop, notebook, embedded and single-socket server systems with up to 8 Mbytes cache. Like previous Intel parts it integrates a memory controller and graphics, now upgraded to support DDR3L DRAMs and Microsoft DirectX 11.0 graphics APIs.

“We spent a lot of time on the modularity of this die to create different flavors of it very quickly,” said Scott Siers, an Intel engineer who presented a paper on the chip at the International Solid-State Circuits Conference here.

Specifically the largest die includes four x86 cores and a large graphics block. It can be chopped along its x- and/or y-axis using automated generation tools to create versions with two cores or a smaller graphics block.

Siers said Ivy Bridge is Intel’s first client chip to support low power 1.35V DDR3L and DDR power gating in standby mode. It handles up to 1,600 MTransfers/s as well as 1.5V DDR3. A new write assist cache circuit provides an average 100 millivolt power reduction.

The Displayport block supports three simultaneous displays including one 1.6 GHz and two 2.7 GHz links with four lanes each.

The PCIe receiver uses a continuous time linear equalizer with 32 gain control levels and a transmitter with a three-tap digital FIR filter. The PCIe block also supports on die testing for jitter as well as timing and voltage margin measurements.

The chip’s x86 and graphics cores can scale in data rates at 100 and 50 MHz increments respectively. Overall, the chip supports five power planes and 180 clock islands that can be separately gated.

In a separate ISSCC keynote, Dadi Perlmutter, chief product officer for Intel, scoped out a long term vision of terahertz-class clients. Terahertz systems consume as much as three kilowatts today but could be reduced to 20W by the end of the decade using a broad variety of techniques, he said.

The techniques include optimizing chips to work at near threshold voltage levels, a subject of several Intel papers at ISSCC. Lower power internal and external interconnects are also needed, he said.

3-D IC packaging will be needed to lower power memory, Permutter said. Toward that end Intel is working with Micron and others on its Hypercube stacked memory design, he said. The design could boost memory bandwidth ten-fold while cutting power to eight pico-joules per bit, down from 50-75 pj/bit in today’s DDR3, he added.

In addition, “voltage regulation has to go into the IC itself because inductance is too big off chip or even on package,” Perlmutter said. “When you have a lot of voltage regulators to turn on and off it becomes very complex to do on a package, so we are working on getting power regulators into the ICs,” he said.

Perlmutter said he sees another 30 years of engineering needed in computing. “For people who thought they could retire from this industry, I say there’s a lot more to do,” he said.

Dadi Perlmutter scoped out challenges to get to terahertz clients.
Intel gives deeper look into Ivy Bridge

TAG:Ivy Bridge Intel X86 Processors ISSCC Ultrabooks

Cuttlefish and their colourblind cousins, squid and octopus, see aspects of light — including polarized light — that are invisible to humans, giving them a covert communication channel. The Bristol study, published today in Current Biology found that cuttlefish were much more sensitive to polarization than previously thought.

Lead researcher Dr Shelby Temple from the Ecology of Vision Laboratory at the University of Bristol said: "Just like colour and intensity, polarization is an aspect of light that can provide animals with information about the world around them. If you’ve ever put on a pair of polarized sunglasses glasses to cut the glare from water or the road, or gone to a recent 3D movie, then you’ve observed some aspects of polarized light."

With collaborators at The University of Queensland, Brisbane, Australia, the team gave cuttlefish an eye exam; but instead of measuring their acuity they measured the smallest difference in the angle of polarization the cuttlefish could detect.

Since the team could not ask the cuttlefish what they could see, they took advantage of the chameleon-like colour changes that cuttlefish use for camouflage as a way of measuring whether the animals could detect the polarized stimuli.

"We modified LCD computer monitors to show changes in polarization instead of changes in colour, and then played videos of approaching objects and watched for changes in skin colour patterns to determine if the cuttlefish could see small changes in polarization contrast," said Dr Temple. "Cuttlefish change colour all the time and respond to the slightest movement so they are an excellent model.

"Cuttlefish were much more sensitive than we expected. It was previously thought that polarization sensitivity was limited to about 10-20 degree differences, but we found that cuttlefish could respond to differences as small as one degree."

In addition to measuring the limits of polarization vision in the cuttlefish, the team also modelled how underwater scenes might look to an animal that has such high-resolution polarization vision. Using colours instead of changes in polarization angle they created images of the polarized world that humans can see and showed that there is much more information available in the polarization dimension than was previously known.

Co-author Professor Justin Marshall of The University of Queensland said: "These extraordinary findings suggest that we need to reexamine how we have been measuring the visual world underwater. Cuttlefish may be using the polarization of light much like we use colour, which means we may need to look at camouflage and communication underwater in a whole new way."

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High definition polarization vision discovered in cuttlefish

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Trofeo Topolino di Sci Alpino sulle nevi degli Altipiani trentini di Folgaria, Lavarone e Luserna
Appuntamento il 2 e 3 marzo per la competizione internazionale giovanile
Tra i testimonial la top model Valeria Mazza, in gara ci sarà suo figlio Balthazar Gravier
45 squadre nazionali in gara per la 51.a edizione

Il 2 e 3 marzo prossimi apre la caccia ai talenti dell’universo bianco con il 51° Trofeo Topolino di Sci Alpino.
Quella del 2012 sarà un’edizione del tutto speciale per la manifestazione giovanile che, dopo il felice cinquantesimo anniversario di un anno fa, animerà ancora una volta le nevi degli Altipiani trentini di Folgaria, Lavarone e Luserna.
Speciale perché, come sempre, si tratta di un’Olimpiade bianca aperta alle categorie Ragazzi (12 e 13 anni) ed Allievi (14 e 15 anni), con la competizione assurta a Criterium Internazionale Giovani FIS fin dal lontano 1970. Speciale anche perché quest’anno tra le nazioni in gara c’è un primato storico, per la prima volta si è iscritta anche la squadra nazionale indiana e, ad oggi, il totale delle rappresentative chiamate a raccolta in Trentino è lievitato a 45.
Recentemente hanno confermato la partecipazione le Nazionali di Colombia, Danimarca, Filippine, Germania, Portogallo, Lettonia, Lituania, Ucraina e Romania, che si aggiungono alla già citata India e ad Andorra, Argentina, Armenia, Australia, Belgio, Bosnia-Erzegovina, Bulgaria, Cile, Croazia, Estonia, Finlandia, Francia, Georgia, Giappone, Gran Bretagna, Islanda, Libano, Liechtenstein, Lussemburgo, Montenegro, Norvegia, Nuova Zelanda, Olanda, Polonia, Repubblica Ceca, Repubblica Slovacca, Russia, San Marino, Serbia, Slovenia, Spagna, Svezia, Svizzera e Ungheria. In questo elenco va inclusa anche l’Italia, con le squadre A e B che verranno selezionate i prossimi 27 e 28 febbraio.
Competizioni, selezioni, tutto andrà in scena nella cornice degli Altipiani di Folgaria, Lavarone e Luserna e, in particolare, nell’arena di Fondo Grande che quest’anno ha accolto già svariate gare FIS e National Junior Race e che, una settimana dopo il Trofeo Topolino, ospiterà anche i Campionati Trentini per Ragazzi e Allievi.
Al Trofeo Topolino lo spettacolo è assicurato anche dal fatto che alle competizioni prendono parte i migliori talenti emergenti internazionali, la manifestazione targata Disney è da sempre un trampolino di lancio per la carriera agonistica futura. A dimostrarlo bastano alcuni dei nomi degli ex partecipanti, che spaziano da Ingemar Stenmark, Marc Girardelli, Gustav Thöni, Giorgio Rocca, Deborah Compagnoni ed Alberto Tomba, fino agli attuali protagonisti del circo bianco come Stefano Gross, Marcel Hirscher, Lara Gut, Ivica Kostelic, Davide Simoncelli, Beat Feuz, Julia Mancuso, Benjamin Raich, Anna Fenninger, Elisabeth Görgl, Tanja Poutiainen, Chiara Costazza, Sofia Goggia, Daniela Merighetti, Denise Karbon e Lindsey Kildow-Vonn.
In tanti hanno partecipato ma non sempre hanno vinto, al Trofeo Topolino, infatti, c’è spazio per l’agonismo ma anche per il puro piacere dello sport e per la passione per la neve, risultati a parte. Proprio il già citato Stefano Gross aveva chiuso il Topolino ’99 al 12° posto nel gigante Ragazzi e, oggi, è tra i cinque migliori slalomisti al mondo, con tre podi di CdM centrati in questa stagione.
Vista la tendenza, anche quest’anno sarà bene tenere d’occhio i piccoli talenti del Trofeo Topolino dato che saranno proprio loro a brillare nel futuro firmamento dello sci internazionale.
Il Trofeo Topolino è da sempre anche occasione per stare insieme, grazie ai tanti eventi di contorno tra cui spicca la cerimonia d’apertura, in programma a Folgaria giovedì 1° marzo (ore 18.30). Anche quest’anno la manifestazione avrà una testimonial d’eccezione, la top model Valeria Mazza, che sarà sulle nevi trentine soprattutto per tifare il figlio Balthazar Gravier, in gara con i colori dell’Argentina. Il talento sudamericano ha partecipato anche alla 50.a edizione dello scorso anno, questa volta arriverà in Italia ancora più agguerrito, forte della vittoria al Campionato Argentino di settembre e del 3° posto centrato al Trofeo Borrufa di fine gennaio, disputato sulle nevi andorrane. Oltre alla bionda argentina e famiglia, al Trofeo Topolino si attendono tanti altri bei nomi, in particolare quello di qualche ex partecipante pronto ad augurare in bocca al lupo ai giovani eredi in gara.
Sabato 25 sarà di scena un appuntamento legato al Trofeo Topolino, ovvero il 44° Premio di Pittura. Dalle 14.30 Piazza Duomo a Trento sarà gremita di tele, colori e tanti piccoli artisti in erba, che dovranno disegnare sul tema “Topolino sulle nevi di Folgaria” utilizzando la tecnica preferita e i materiali messi a disposizione dall’organizzazione.
La 51.a edizione del Trofeo Topolino di Sci Alpino è orchestrata ancora una volta dal C.O. presieduto dall’infaticabile Mauro Detassis, con la vice presidente Marisa Ruatti e la segretaria generale Cinzia Longhi Gennari. Info: www.trofeotopolino.net

CAMPIONI A RACCOLTA PER IL TROFEO TOPOLINO. APPUNTAMENTO MONDIALE A FOLGARIA (TN)

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