Featured Research

from universities, journals, and other organizations

New Unidirectional Molecular Rotor May Lead To Tiny Sensors, Pumps, Switches

Date:
October 7, 2005
Source:
University of Colorado at Boulder
Summary:
A University of Colorado at Boulder team has developed the first computer-generated model of a tiny, waterwheel-like molecular rotor that has been harnessed to rotate in one direction at different speeds in response to changes in the strength of an electrical field applied from the outside.

A University of Colorado at Boulder team has developed the first computer-generated model of a tiny, waterwheel-like molecular rotor that has been harnessed to rotate in one direction at different speeds in response to changes in the strength of an electrical field applied from the outside. (Still image from animation courtesy of PNAS/CU-Boulder)

A University of Colorado at Boulder team has developed the firstcomputer-generated model of a tiny, waterwheel-like molecular rotorthat has been harnessed to rotate in one direction at different speedsin response to changes in the strength of an electrical field appliedfrom the outside.

Related Articles


The synthetic molecule features a chemical axle with two attached"paddles" carrying opposite electrical charges, which is mountedparallel to a gold substrate surface, said Professor Josef Michl ofCU-Boulder's chemistry and biochemistry department. The researchersfound that the microscopic rotor -- constructed with a few hundredatoms -- will turn in a desired direction at a selected frequency usingan oscillating electrical field concentrated in a tiny area above themolecule.

Such molecular rotors may someday function as nanotechnology machinesand be used as chemical sensors, cell-phone switches, miniature pumpsor even laser-blocking goggles, he said. A paper by Michl and formerCU-Boulder postdoctoral student Dominik Horinek, the Feodr Lynen Fellowof the German Humboldt Foundation, appeared in the Oct. 4 issue of theProceedings of the National Academy of Sciences.

In March 2004, the CU-Boulder research group led by Michl reported thesynthesis of these molecules and their mounting on a gold surface --the world's first surface-mounted artificial molecular rotor, whichturned spontaneously in random directions at room temperatures. Whilethe team was able to make the rotor "flip" using electricity, the newcomputer model indicates such rotors can be harnessed to turn in one,desired direction at varying, prescribed speeds, he said.

"We are very pleased," said Michl. "The computer model tells us we willbe able to manipulate the frequency of rotor revolutions by changingthe strength of the outside electrical field."

The researchers were able to make the new molecular rotor model turn atthree different speeds by adjusting the electrical field strength at agiven oscillation frequency, he said. The behavior of the rotorresponds both to the imposed electrical field and frictional dragwithin the gold substrate on which the device is anchored, as well asthe natural thermal movements of molecules, known as Brownian motion.

The molecular rotors designed and constructed by Michl and hiscolleagues are an outgrowth of a "Molecular Tinkertoy Kit" the groupdeveloped in the 1990s. Made up of chemical rods and connectors tens ofthousands of times smaller than the width of a human hair, the parts --which are made primarily of carbon atoms-- have been used to assemble avariety of simple nanostructures over the past decade.

Complex molecular motors, including the protein, ATPase -- which fuelsmost cellular processes in living things -- are found throughout thenatural world, Michl said. "Ours is much more primitive and one hundredtimes smaller, and is but a first step."

Michl's group hopes to design a rotor with larger "paddles"and to power it with either a liquid or gas fluid rather thanelectricity. "Ultimately, we would like to use light pulses to drivethe rotor and make it pump fluid. At that point we would have a motor,which is something that actually does useful work, rather than a rotor,which merely idles."

Michl said modeling the behavior of molecular rotors with powerfulcomputers saves a significant amount of time and money in the researchprocess. "Modeling allows us to discard designs that are not fruitful,"he said. "We can save a lot of labor and cost by modeling them in thecomputer first, and only then synthesizing them in the laboratory."

Michl is collaborating with several others in CU-Boulder's chemistryand biochemistry department, including research associates ThomasMagnera and Jaroslav Vacek and graduate students Debra Casher and MaryMulcahy. He also works closely with Professors Charles Rogers and JohnPrice of the CU-Boulder physics department, as well as faculty membersat Northwestern University.

Funded primarily by the U.S. Army Research Office and theNational Science Foundation, the research could lead to new technologyto produce goggle coatings that would shield human eyes from blindinglasers, said Michl. Arrays of rotors laid down in a protective coatingwould rest perpendicular to the goggle surface and allow light through.But when a laser pulse arrived at the goggles, the rotors would pushthe paddles into a parallel position to block incoming light.

Michl is one of 19 CU-Boulder faculty members who have been elected tothe National Academy of Sciences, which publishes the Proceedings ofthe National Academy of Sciences.

###

A movie animation/ still image, courtesy of PNAS/CU-Boulder, is available at: http://www.pnas.org/content/vol0/issue2005/images/data/0506183102/DC1/06183Movie1.mpg


Story Source:

The above story is based on materials provided by University of Colorado at Boulder. Note: Materials may be edited for content and length.


Cite This Page:

University of Colorado at Boulder. "New Unidirectional Molecular Rotor May Lead To Tiny Sensors, Pumps, Switches." ScienceDaily. ScienceDaily, 7 October 2005. <www.sciencedaily.com/releases/2005/10/051007084318.htm>.
University of Colorado at Boulder. (2005, October 7). New Unidirectional Molecular Rotor May Lead To Tiny Sensors, Pumps, Switches. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2005/10/051007084318.htm
University of Colorado at Boulder. "New Unidirectional Molecular Rotor May Lead To Tiny Sensors, Pumps, Switches." ScienceDaily. www.sciencedaily.com/releases/2005/10/051007084318.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
Raw: Paralyzed Marine Walks With Robotic Braces

Raw: Paralyzed Marine Walks With Robotic Braces

AP (Nov. 21, 2014) Marine Corps officials say a special operations officer left paralyzed by a sniper's bullet in Afghanistan walked using robotic leg braces in a ceremony to award him a Bronze Star. (Nov. 21) Video provided by AP
Powered by NewsLook.com
British 'Bio-Bus' Is Powered By Human Waste

British 'Bio-Bus' Is Powered By Human Waste

Buzz60 (Nov. 21, 2014) British company GENeco debuted what its calling the Bio-Bus, a bus fueled entirely by biomethane gas produced from food scraps and sewage. Jen Markham explains. Video provided by Buzz60
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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