Featured Research

from universities, journals, and other organizations

Researchers measure single-molecule machines in action

Date:
July 7, 2010
Source:
University of California - Los Angeles
Summary:
In the development of future molecular devices, new display technologies, and "artificial muscles" in nanoelectromechanical devices, functional molecules are likely to play a primary role. Rotaxanes, one family of such molecules, are tiny, mechanically interlocked structures that consist of a dumbell-shaped molecule whose rod section is encircled by a ring. These structures behave as molecular "machines," with the ring moving along the rod from one station to another when stimulated by a chemical reaction, light or acidity.

Rotaxane, showing movement of ring to different stations along the rod.
Credit: Image courtesy of University of California - Los Angeles

In the development of future molecular devices, new display technologies, and "artificial muscles" in nanoelectromechanical devices, functional molecules are likely to play a primary role.

Rotaxanes, one family of such molecules, are tiny, mechanically interlocked structures that consist of a dumbell-shaped molecule whose rod section is encircled by a ring. These structures behave as molecular "machines," with the ring moving along the rod from one station to another when stimulated by a chemical reaction, light or acidity.

To realize the potential of these molecular machines, however, it is necessary to understand and to measure their function at the nanoscale. Previous methods for observing their operation have involved chemical measurements in solution and studying collections of them attached to surfaces, but neither has provided an accurate picture of their function in environments that are relevant to molecular-device operation.

Now, a multidisciplinary team of researchers from UCLA, Northwestern University, UC Merced, Pennsylvania State University and Japan has succeeded in observing single-molecule interactions of bistable rotaxanes functioning in their native environment.

The team's findings are published in the current edition of the journal ACS Nano.

Led by Paul Weiss from UCLA and Fraser Stoddart from Northwestern University, the team developed a molecular design that firmly attached rotaxanes to a surface, enabling them to be individually examined in their native environment by a scanning tunneling microscope (STM). Using this technology, the researchers were able to record station changes by the rotaxanes' rings along their rods in response to electrochemical signals.

Previously, rotaxanes had to be grouped for study because of their mobility and flexibility when attached to surfaces. And because STM instruments utilize an atomically thin tip to feel out nanoscale surfaces ― in much the same way a blind person reads Braille ― the rotaxanes' flexible nature made it difficult to study them individually. The research team's molecular design, however, helped significantly reduce this flexibility.

The STM developed by the team enables much more detailed studies of molecular machines, leading to greater understanding of how they interact with their neighbors and how they might work together in nanoelectromechanical devices.

Paul Weiss, distinguished professor of chemistry and biochemistry, holds UCLA's Fred Kavli Chair in Nanosystems Sciences and is director of the California NanoSystems Institute (CNSI) at UCLA. Fraser Stoddart is the Board of Trustees Professor of Chemistry and director of the Center for the Chemistry of Integrated Systems (CCIS) at Northwestern University.

The work was funded by the National Science Foundation, the Semiconductor Research Corporation and the Kavli Foundation.


Story Source:

The above story is based on materials provided by University of California - Los Angeles. The original article was written by Mike Rodewald. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tao Ye, Ajeet S. Kumar, Sourav Saha, Tomohide Takami, Tony J. Huang, J. Fraser Stoddart, Paul S. Weiss. Changing Stations in Single Bistable Rotaxane Molecules under Electrochemical Control. ACS Nano, 2010; 100611142920062 DOI: 10.1021/nn100545r

Cite This Page:

University of California - Los Angeles. "Researchers measure single-molecule machines in action." ScienceDaily. ScienceDaily, 7 July 2010. <www.sciencedaily.com/releases/2010/07/100706130322.htm>.
University of California - Los Angeles. (2010, July 7). Researchers measure single-molecule machines in action. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2010/07/100706130322.htm
University of California - Los Angeles. "Researchers measure single-molecule machines in action." ScienceDaily. www.sciencedaily.com/releases/2010/07/100706130322.htm (accessed April 16, 2014).

Share This



More Matter & Energy News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
Powered by NewsLook.com
Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

TheStreet (Apr. 16, 2014) The Porsche Spyder 918 proves that, in an automotive world obsessed with fuel efficiency, the supercar is not dead. Porsche North America CEO Detlev von Platen attributes the brand's consistent sales growth -- 21% in 2013 -- with an investment in new technology and expanded performance dynamics. The hybrid Spyder 918 has 887 horsepower and 944 lb-ft of torque, but it can run 18 miles on just an electric charge. The $845,000 vehicle is not a consumer-targeted vehicle but a brand statement. Video provided by TheStreet
Powered by NewsLook.com
Ford Mustang Fetes Its 50th Atop Empire State Building

Ford Mustang Fetes Its 50th Atop Empire State Building

AFP (Apr. 16, 2014) Ford celebrated the 50th birthday of its beloved Mustang by displaying a new model of the convertible on top of the Empire State Building in New York. Duration: 00:28 Video provided by AFP
Powered by NewsLook.com
New York Auto Show Highlights Latest in Car Tech

New York Auto Show Highlights Latest in Car Tech

AP (Apr. 16, 2014) With more than 1 million visitors annually, the New York International Auto Show is one of the most important shows for the U.S. auto industry. This year's show featured the latest in high technology, and automotive bling. (April 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins