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 September 15, 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 September 15, 2014).

Share This



More Matter & Energy News

Monday, September 15, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Frustration As Drone Industry Outpaces Regulation In U.S.

Frustration As Drone Industry Outpaces Regulation In U.S.

Newsy (Sep. 14, 2014) U.S. firms worry they’re falling behind in the marketplace as the FAA considers how to regulate commercial drones. Video provided by Newsy
Powered by NewsLook.com
Smart Gun Innovators Fear Backlash From Gun Rights Advocates

Smart Gun Innovators Fear Backlash From Gun Rights Advocates

Newsy (Sep. 14, 2014) Winners of a contest for smart gun design are asking not to be named after others in the industry received threats for marketing similar products. Video provided by Newsy
Powered by NewsLook.com
Scientists Have Captured The Sound Of An Atom

Scientists Have Captured The Sound Of An Atom

Newsy (Sep. 12, 2014) Scientists have captured the sound of a single atom by measuring its vibrations. We can't hear it, but it's reportedly the faintest sound possible. Video provided by Newsy
Powered by NewsLook.com
Solar Flare Surges Off Sun

Solar Flare Surges Off Sun

Reuters - US Online Video (Sep. 11, 2014) NASA captures video of a significant flare surging off the sun. Jillian Kitchener reports. Video provided by Reuters
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