Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Molecular machines drive plasmonic nanoswitches

13.02.2009
Plasmonics -- a possible replacement for current computing approaches -- may pave the way for the next generation of computers that operate faster and store more information than electronically-based systems and are smaller than optically-based systems, according to a Penn State engineer who has developed a plasmonic switch.

"If plasmonics are realized, the future will have circuits as small as the current electronic ones with a capacity a million times better," said Tony Jun Huang, James Henderson assistant professor of Engineering Science and Mechanics. "Plasmonics combines the speed and capacity of photonic -- light based -- circuits with the small size of electronic circuits."

Currently, electronic circuits can be made very small, but they are limited by their capacity and the speed that information can travel in the circuits. Optical circuits send information at the speed of light, but the size is large, limited by the light's wavelength. Plasmonics combines the best of electronic and optical circuits and can transmit electrons and light at the same time using the surface of the device.

Huang's team created a plasmonic switch from switchable bistable rotaxanes. Rotaxanes are complex molecules that consist of a dumbbell shape with a ring or rings encircling the shaft and are sometimes called molecular machines. The ring can either move from one end of the barbell to the other or rotate around the shaft. Changes in molecular shape are the basis of the plasmonic switch.

Computers, in their simplest form, are machines that can say yes or no multiple times to transfer information. The motion of a molecule can serve the same purpose as the on off switch on a light.

The researchers attached their molecular machines to gold-coated nanodiscs fabricated on glass. The machines were attached with disulfide functional groups. The dumbbell shaped molecules have two areas of the shaft primed with two different chemicals. The ring is initially drawn to circle at one primed area. When the chemical there is oxidized, the ring is repelled and moves to the other primed area, flipping the switch. The process is reversible, so the ring returns to its original state to switch on again later. When the molecule moves, it changes the surface plasmon resonance in that tiny area of the metal where it is attached. This change in resonance is what would send the signal on the circuit. The plasmonic switch that Huang and his team developed is not yet part of a circuit.

"Plasmonic circuits have not yet been achieved," said Huang. "In the past, the plasmonic devices made were all passive." These devices were used as light sources, lenses and waveguides

Huang's switches are activated by a chemical process, however, this is not the optimal choice for a working circuit.

"We believe that the chemically-driven redox process can be replaced with direct electrical or optical stimulation, a logical development that would establish a technological basis for the production of a new class of molecular-machine-based active plasmonic components for solid-state nanophotonic integrated circuits with the potential for low-energy and ultra small operations," the researchers state in a recent issue of Nano Letters.

In essence, plasmonic devices would allow computers to get faster and have more memory storage in smaller spaces. Storage of as much as 1,000 movies on a typical USB drive would be possible. Huang suggests that applications like YouTube, which are very popular but have terrible resolution, could become places to see high-resolution images.

"We are in the very beginning of this field," said Huang. "Creation of a plasmonic circuit is probably five years away."

A'ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

More articles from Physics and Astronomy:

nachricht Four elements make 2-D optical platform
26.09.2017 | Rice University

nachricht The material that obscures supermassive black holes
26.09.2017 | Instituto de Astrofísica de Canarias (IAC)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>