Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Self-assembled nanocells function as non-volatile memory

20.10.2003


First use of disordered nanowires, organic molecules as programmable memory



Chemists at Rice University have demonstrated that disordered assemblies of gold nanowires and conductive organic molecules can function as non-volatile memory, one of the key components of computer chips.

"A large part of the cost associated with creating integrated circuits comes from the painstaking precision required to ensure that each of the millions of circuits on the chip are placed in exactly the right spot," said lead researcher Jim Tour, an organic chemist at Rice. "Our research shows that ordered precision isn’t a prerequisite for computing. It is possible to make memory circuits out of disordered systems."


The research appears in the Oct. 29 issue of the Journal of the American Chemical Society. It marks the first time that a self-assembled ensemble of molecular electronic components has been used to create complex devices that carry out basic computing functions. Dubbed NanoCells, the devices were shown to function as re-programmable memory with memory states that hold for more than a week at room temperature, and probably far longer. Present-day dynamic random access memory, or DRAM, only holds its memory state for about one hundredth of a second and must be refreshed every thousandth of a second.

In previous experiments, Tour, the Chao Professor of Chemistry and professor of computer science, mechanical engineering and materials science, has used single molecules as switches, memory devices, resistors, diodes, junctions and wires. The creation of the prototype NanoCell marks the first time such molecules have been used to form a working microelectronic device.

The NanoCell consists of a set of discontinuous islands of gold film that are vapor-deposited onto a flat rectangle of silicon dioxide measuring about 40 microns by 10 microns. By submersing the sliver of silicon dioxide into a liquid solution of precisely synthesized organic molecules and gold nanowires, Tour is able to create conductive links between the islands of gold foil. Ten gold leads spaced five microns apart around the perimeter of the NanoCell carry electronic signals to and from the device. The size of the host platform is not critical, so the technology can scale down to much smaller sizes.

Compared to metal-oxide semiconductor technology, molecular electronic devices like NanoCells, offer the potential to reduce device size and fabrication costs by several orders of magnitude. With the NanoCell architecture, Tour hopes to address the nanoscale via the microscale, taking advantage of the ultrasmall molecules using current lithographic tools.

In addition to memory, Tour’s group is actively studying how NanoCells can be used to as logic gates. Since the precise placement of components is disordered, the NanoCells can’t be programmed like today’s computers. Instead, they must be trained to carry out specific logical functions. Even if this process is only a few percent efficient in the use of molecular devices, it could result in very high logic densities, making it possible for computer makers to create much more powerful chips.

The JACS paper, titled "NanoCell Electronic Memories," was co-authored by Tour, postdoctoral researchers Long Cheng and Yuxing Yao, graduate student Austen Flatt, Penn State chemist Thomas Mallouk and his graduate student Sarah St. Angelo, and North Carolina State electrical engineer Paul Franzon and his graduate student David Nackashi.


The research was sponsored by the Defense Advanced Research Projects Agency, the Office of Naval Research and Molecular Electronics Corp.

Jade Boyd | EurekAlert!
Further information:
http://chico.rice.edu/

More articles from Interdisciplinary Research:

nachricht Investigating cell membranes: researchers develop a substance mimicking a vital membrane component
25.05.2018 | Westfälische Wilhelms-Universität Münster

nachricht New approach: Researchers succeed in directly labelling and detecting an important RNA modification
30.04.2018 | Westfälische Wilhelms-Universität Münster

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication

16.07.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>