Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Good Memory

Abstract:
On the way to plastic electronics: polymer-based dynamic random access memory (DRAM)

Good Memory

Posted on April 14, 2006

Smaller, lighter, more compact devices that can do more and more, work faster, and juggle more data—these demands are pushing conventional semiconductor technology up against its limits. In the future, plastics will have to take over. A number of polymeric electronic components have already been made. Researchers at the National University of Singapore and the Institute of Microelectronics in Singapore have now successfully produced DRAM storage based on a plastic.

The Singaporean team also recently made flash memory (a rewritable memory) and write-once read-many-times (WORM) memory based on polymers. Now they have introduced another type of memory, dynamic random access memory (DRAM), based on a polymer. In this “short-term” or “dynamic” memory, electronic devices temporarily store all processes—storage units are updated by refreshing voltage pulses.

In contrast to a semiconductor chip, which “keeps track” of data in the form of electrical charge, the “0” and “1” signals in polymer-based memory are stored as high and low conductivity, respectively. The researchers produced a special copolymer, a plastic whose long molecular chains are made of two different components that are finely tuned to each other. This polymer is embedded as a thin film between two electrodes. The polymer is initially in the OFF state, which is characterized by low conductivity. A barrier hinders the flow of electrons through the film. In order to “write” to the memory, a low voltage above a certain threshold (-2.8 V) is enough to switch the copolymer into a highly conducting state, the ON state. The memory is “read” by means of voltage pulses below the threshold. The secret behind this device is the combination of the barrier and a kind of “pit trap” for charge carriers. If the barrier is first overcome above the threshold, the pits are filled with charge carriers. The altered electrical field then causes the barrier to become ineffective. The current can then flow through the film unhindered. The pits are “shallow”, which allows the charge carriers to come out easily: If no voltage is applied for over two minutes they “climb” out of the pits on their own and the memory “forgets” its programming and returns to the OFF state. This is just what it should do as “dynamic” memory. “Erasing” the memory is accomplished by an opposing voltage pulse above +3.5 V. This immediately returns the memory to the original OFF state with empty traps. Renewed application of more than -2.8 V always returns the memory to its writeable state.

####


Author: En-Tang Kang, National University of Singapore (Singapore), www.chee.nus.edu.sg/staff/kang.html

Title: A Dynamic Random Access Memory (DRAM) Based on a Conjugated Copolymer Containing Electron-Donor and -Acceptor Moieties

Angewandte Chemie International Edition, 2006, 45, No. 18, 2947–2951, doi: 10.1002/anie.200504365

Contact:
Editorial office:
angewandte@wiley-vch.de

or David Greenberg (US)
dgreenbe@wiley.com

or Julia Lampam (UK)
jlampam@wiley.co.uk

Copyright © Angewandte Chemie

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Memory Technology

Nano memory cell can mimic the brain’s long-term memory May 14th, 2015

Silicon Storage Technology and GLOBALFOUNDRIES Announce Qualification of Automotive Grade 55nm Embedded Flash Memory Technology May 5th, 2015

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Materials/Metamaterials

Haydale Named Lead Sponsor for Cambridge Graphene Festival May 22nd, 2015

Supercomputer unlocks secrets of plant cells to pave the way for more resilient crops: IBM partners with University of Melbourne and UQ May 21st, 2015

Researchers develop new way to manufacture nanofibers May 21st, 2015

Taking control of light emission: Researchers find a way of tuning light waves by pairing 2 exotic 2-D materials May 20th, 2015

Announcements

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

New Antibacterial Wound Dressing in Iran Can Display Replacement Time May 22nd, 2015

Haydale Named Lead Sponsor for Cambridge Graphene Festival May 22nd, 2015

INSIDDE: Uncovering the real history of art using a graphene scanner May 21st, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project