Category: Nanodot

Posted by Robert Bradbury: Mike Treder writes “Nanotechnology’s long-expected transformation of manufacturing has just moved closer to reality. A new analysis of existing technological capabilities, including proposed steps from today’s nanotech to advanced molecular machine systems, was released today by the Center for Responsible Nanotechnology“. The study, “Molecular Manufacturing: What, Why and How,” performed by… Continue reading Moving closer to "real" molecular manufacturing

Scientists Brew Tree-Shaped DNA: "Researchers from Cornell University have synthesized a new type of DNA that can be used as a nanotechnology building block. … The Cornell researchers have found a way to make branched, or Y-shaped DNA, and have constructed dendrimer, or tree-shaped, DNA by connecting branched DNA." Alternate URL

from the more-than-one-way-to-small-electronics dept.
Gina Miller writes "A Chemical & Engineering News cover story from Sept. 30 available online — Nanoscale Electronics — provides a readable and well-illustrated overview of current progress in molecular electronics, carbon nanotube electronics, and semiconducting nanowire research."

from the very-small-but-very-slow dept.
Gina Miller writes "A Sept. 3 press release from the University of Wisconsin at Madison Scientists develop atomic-scale memory reports that scientists have been able to read and write at room temperature to a memory that uses a single atom to store a bit. Silicon atoms are dispersed on a self-assembled surface of gold atoms so that each silicon atom fits into a pocket formed by 20 surrounding gold atoms. An STM tip is used to remove specific silicon atoms to write to the memory. Although the storage density is very high, writing with an STM tip is very slow."

Steve Lenhert writes "Encyclopedia Nanotech is an online dictionary/encyclopedia for nanotech-related terminology. The goal of this 'nanoword network' is to provide a transdisciplinary reference point for the various words we use in nanotechnology. I am posting here in order to solicit constructive criticism and stimulate semantic discussions about these terms.

Read more for additional details.

Gina Miller writes "AScribe reports on March 14, 2002 Using 'Nature's Toolbox,' DNA Computer Solves Complex Problem; Molecular Technology May One Day Outstrip Computers. Leonard Adleman, computer science professor at USC famed for his 1994 demonstration that DNA could be used for computation, has now used a DNA based computer to solve a logic problem (a 20-variable instance of the NP-complete three-satisfiability (3-SAT) problem) that required an exhaustive search of more than a million possibilities. Unlike the simple problem solved by his 1994 demonstration, which could easily be solved by a human with pencil and paper, no human could solve this problem without the aide of a computer. Although the current massively parallel DNA computer could not match the performance of a modern electronic serial computer, it could have advantages in certain situations. "We've shown by these computations that biological molecules can be used for distinctly non-biological purposes," Adleman said. "They are miraculous little machines. They store energy and information, they cut, paste and copy." For another approach to computation with DNA, see the Nanodot post from 23 November 2001."

The media drumbeat touting molecular electronics as the first likely wide-scale applications of nanotechnology is getting louder:

• An article in EE Times ("Researchers close to delivering molecular circuits", by Chappell Brown, 15 February 2002) says "Although it's a little like watching a chess match in slow motion, molecular electronics researchers are converging on viable circuit-fabrication methods. Several approaches to building circuits with molecules reached the stage of at least rudimentary logic or simple devices, such as inverters or AND gates, last year."
• The looming advent of nanoelectronics was also highlighted at this yearís annual meeting of the American Association for the Advancement of Science (AAAS) in Boston, 14-19 February 2002. A press release from the AAAS (14 February 2002) says "A landslide of discoveries brought the promise of powerful electronic and computing devices, built at the molecular scale, to the forefront of scientific research in 2001. In particular, several research teams hooked up tiny devices such as transistors, wires, and switches to form working circuits for the first time", and describes the many advances by researchers in the field in the past year. "We may be five to six years ahead of schedule in nanoelectronics, and some of today's research is nearing the stage where it could be turned over to industrial production . . . It's been a momentous period for nanoelectronics, with more in store for the future," said James Ellenbogen of the Mitre Corporation. In December 2001, the editors of the journal Science, which is published by the AAAS, highlighted the field of molecular electronics as this yearís "Breakthrough of the Year" in a special issue of the journal (20 December 2001).
• More coverage of the molectronics buzz at the AAAS meeting was provided by an article from the Atlanta Constitution ("Science gathering predicts a big future for small tech", by Mike Toner, 15 February 2002) that appeared on the Small Times website. Recent advances in molectronics, Toner writes, are "the harbingers of a new epoch" that "might make it possible to develop a generation of nanorobots that could fight disease on a molecular level, biochemical sensors that could detect a single anthrax cell and computer storage devices that could pack the contents of the Library of Congress in the space of a sugar cube. . . . One by one, researchers are marshalling the building blocks of a market the National Science Foundation estimated could grow to $1 trillion and employ 2 million people over the next 10 to 15 years." The article also quotes nanotech researcher Charles Lieber, a Harvard chemistry professor and winner of the 2001 Foresight Feynman Prize for Experimental work: "A year ago, I wasn't sure that the achievement of a complex integrated nanosystem was possible. Now I think it is a distinct possibility in the near future."

from the Molectronics dept.
The cover and a pair of feature articles in the February 2002 issue of Materials Today, an international magazine devoted to the latest research and policy news for materials researchers in academia, industry and government, highlight "Molecular electronics: the future of computing". The two feature articles are available on the MT website, as Adobe Acrobat PDF files. (Note: the PDF files have been print-disabled, so you can only view the articles online.)

• "Introducing molecular electronics" by Mark Ratner. This article introduces the basic concepts of molecular electronics, looks at the promise that molecular electronics holds, and describes the fundamental questions that still have to be answered for these promises to be fulfilled. Ratner, a Professor of Chemistry at Northwestern University, was one of the visionary co-inventors of the concept and scientific study of molecular electronics. He was awarded the 2001 Feynman for Theoretical Work at the Ninth Foresight Conference on Molecular Nanotechnology in November 2001.
• "Moletronics: future electronics" by Kwan Kwok with DARPA and James Ellenbogen of MITRE Corp. This extensive and well-illustrated article surveys recent work in the field of molecular electronics.
• "Nanowires take the prize" (not available online) is a news item and interview of Charles Lieber, a molecular devices researcher at Harvard who was awarded the 2001 Feynman Prize for Experimantal Work. "We have these things as chemical or building blocks there to be manipulated. You can combine things that you just didnít think you could combine. You can bring functionality to the table that really isnít possible by other means," says Lieber.

waynerad spotted an item in Electronic Engineering Times ("Towards the single molecule transistor", by Nolan Fell, 24 January 2002) that provides a brief update on work by Bell Labs' physicists Hendrik Schön and Shenan Bao, who report they have developed a FET combining both insulator and semiconductor layers within a single organic molecule. "The combination of insulating and semiconducting parts could lead to true single-molecule transistors," said Schön. "We need now to develop a more complex molecular design and connect them to some kind of contact." A technical report appeared in the 14 January 2002 issue of Applied Physics Letters. Earlier Nanodot posts on the Bell Labs molecular transistors appeared on 17 December and 8 November 2001.

Vik points to an article in Technology Research News ("Morphing DNA makes motor", by Kimberly Patch, 16 January 2002) on the research by Nadrian Seeman at New York University into DNA-based devices:

"Dr. Nadrian Seeman has created and tested a 4-step DNA motor that can rotate indefinitely. Fuelled by other DNA strands, the molecular motor described in [the] TRN article operates in controllable steps. Dr. Seeman says that the range of motion is from 0.04 to 4 nm, although movement of 35nm has been made using arrays of the devices."

This item was also reported here on 2 January 2002.