Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Light twists rigid structures in unexpected nanotech finding

After 72 hours of exposure to ambient light, strands of nanoparticles twisted and bunched together. Credit: Nicholas Kotov
After 72 hours of exposure to ambient light, strands of nanoparticles twisted and bunched together. Credit: Nicholas Kotov

Abstract:
In findings that took the experimenters three years to believe, University of Michigan engineers and their collaborators have demonstrated that light itself can twist ribbons of nanoparticles.

The results are published in the current edition of Science.

Light twists rigid structures in unexpected nanotech finding

Ann Arbor, MI | Posted on March 17th, 2010

Matter readily bends and twists light. That's the mechanism behind optical lenses and polarizing 3-D movie glasses. But the opposite interaction has rarely been observed, said Nicholas Kotov, principal investigator on the project. Kotov is a professor in the departments of Chemical Engineering, Biomedical Engineering and Materials Science and Engineering.

While light has been known to affect matter on the molecular scale—bending or twisting molecules a few nanometers in size—it has not been observed causing such drastic mechanical twisting to larger particles. The nanoparticle ribbons in this study were between one and four micrometers long. A micrometer is one-millionth of a meter.

"I didn't believe it at the beginning," Kotov said. "To be honest, it took us three and a half years to really figure out how photons of light can lead to such a remarkable change in rigid structures a thousand times bigger than molecules."

Kotov and his colleagues had set out in this study to create "superchiral" particles—spirals of nano-scale mixed metals that could theoretically focus visible light to specks smaller than its wavelength. Materials with this unique "negative refractive index" could be capable of producing Klingon-like invisibility cloaks, said Sharon Glotzer, a professor in the departments of Chemical Engineering and Materials Science and Engineering who was also involved in the experiments. The twisted nanoparticle ribbons are likely to lead to the superchiral materials, the professors say.

To begin the experiment, the researchers dispersed nanoparticles of cadmium telluride in a water-based solution. They checked on them intermittently with powerful microscopes. After about 24 hours under light, the nanoparticles had assembled themselves into flat ribbons. After 72 hours, they had twisted and bunched together in the process.

But when the nanoparticles were left in the dark, distinct, long, straight ribbons formed.

"We discovered that if we make flat ribbons in the dark and then illuminate them, we see a gradual twisting, twisting that increases as we shine more light," Kotov said. "This is very unusual in many ways."

The light twists the ribbons by causing a stronger repulsion between nanoparticles in them.

"The twisted ribbon is a new shape in nanotechnology," Kotov said. "Besides superchiral materials, he envisions clever applications for the shape and the technique used to create I it. Sudhanshu Srivastava, a postdoctoral researcher in his lab, is trying to make the spirals rotate."

"He's making very small propellers to move through fluid—nanoscale submarines, if you will," Kotov said. "You often see this motif of twisted structures in mobility organs of bacteria and cells."

The nanoscale submarines could conceivably be used for drug-delivery and in microfluidic systems that mimic the body for experiments.

This newly-discovered twisting effect could also lead to microelectromechanical systems that are controlled by light. And it could be utilized in lithography, or microchip production.

Glotzer and Aaron Santos, a postdoctoral researcher in her lab, performed computer simulations that helped Kotov and his team better understand how the ribbons form. The simulations showed that under certain circumstances, the complex combination of forces between the tetrahedrally-shaped nanoparticles could conspire to produce ribbons of just the width observed in the experiments. A tetrahedron is a pyramid-shaped, three-dimensional polyhedron.

"The precise balance of forces leading to the self-assembly of ribbons is very revealing," Glotzer said. "It could be used to stabilize other nanostructures made of non-spherical particles. It's all about how the particles want to pack themselves."

Other collaborators include researchers from the University of Leeds in the UK, Chungju National University in Korea, Argonne National Laboratory, Pusan National University in Korea and Jiangnan University in China.

The paper is titled Light-Controlled Self-Assembly of Semiconductor Nanoparticles into Twisted Ribbons. The research is funded by the Air Force Office of Scientific Research, the Korea Science and Engineering Foundation and the U.S. Department of Energy.

####

About University of Michigan College of Engineering
Michigan Engineering: The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At $160 million annually, its engineering research budget is one of largest of any public university. Michigan Engineering is home to 11 academic departments and a National Science Foundation Engineering Research Center. The college plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world class Lurie Nanofabrication Facility. Michigan Engineering's premier scholarship, international scale and multidisciplinary scope combine to create The Michigan Difference.

For more information, please click here

Contacts:
Nicole Casal Moore
Phone: (734) 647-7087

Copyright © University of Michigan College of Engineering

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

News and information

Maximum Precision in 3D Printing: New complete solution makes additive manufacturing standard for microfabrication February 26th, 2015

Real-time observation of bond formation by using femtosecond X-ray liquidography February 26th, 2015

Bruker-Sponsored Sixth AFM BioMed Conference Highlights Increasing Impact of AFM in Biological Applications February 26th, 2015

Graphene shows potential as novel anti-cancer therapeutic strategy: University of Manchester scientists have used graphene to target and neutralise cancer stem cells while not harming other cells February 26th, 2015

Display technology/LEDs/SS Lighting/OLEDs

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

QD Vision Named Edison Award Finalist for Innovative Color IQ™ Quantum Dot Technology February 23rd, 2015

JunPus launched high-performance thermal grease for LED February 20th, 2015

Penn researchers develop new technique for making molybdenum disulfide: Extra control over monolayer material with advantages over graphene February 19th, 2015

Microfluidics/Nanofluidics

Going with the flow January 16th, 2015

How bacteria control their size: By monitoring thousands of individual bacteria scientists discovered how they maintain their size from generation to generation January 6th, 2015

“Line dancing bacteria win the 2014 Dolomite and Lab on a Chip Video Competition” December 16th, 2014

Dolomite launches Mitos Dropix® Droplet Splitting System December 1st, 2014

Govt.-Legislation/Regulation/Funding/Policy

Warming up the world of superconductors: Clusters of aluminum metal atoms become superconductive at surprisingly high temperatures February 25th, 2015

SUNY Poly CNSE Researchers and Corporate Partners to Present Forty Papers at Globally Recognized Lithography Conference: SUNY Poly CNSE Research Group Awarded Both ‘Best Research Paper’ and ‘Best Research Poster’ at SPIE Advanced Lithography 2015 forum February 25th, 2015

European roadmap for graphene science and technology published February 25th, 2015

Cutting-edge technology optimizes cancer therapy with nanomedicine drug combinations: UCLA bioengineers develop platform that offers personalized approach to treatment February 24th, 2015

Possible Futures

European roadmap for graphene science and technology published February 25th, 2015

Quantum research past, present and future for discussion at AAAS February 16th, 2015

World’s first compact rotary 3D printer-cum-scanner unveiled at AAAS by NTU Singapore start-up: With production funded by crowdsourcing, the first unit will be delivered to the United States in March February 16th, 2015

Nanotechnology Electric Vehicle (EV) Market Analysis Report 2015: According to Radiant Insights, Inc February 13th, 2015

Academic/Education

NanoTecNexus Launches New App for Learning About Nanotechnology—STEM Education Project Spearheaded by Interns February 26th, 2015

SUNY Poly CNSE Researchers and Corporate Partners to Present Forty Papers at Globally Recognized Lithography Conference: SUNY Poly CNSE Research Group Awarded Both ‘Best Research Paper’ and ‘Best Research Poster’ at SPIE Advanced Lithography 2015 forum February 25th, 2015

KIT Increases Commitment in Asia: DAAD Funds Two New Projects: Strategic Partnerships with Chinese Universities and Communi-cation Technologies Network February 22nd, 2015

Minus K Technology Announces Its 2015 Vibration Isolator Educational Giveaway to U.S. Colleges and Universities February 18th, 2015

Chip Technology

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

SUNY Poly CNSE Researchers and Corporate Partners to Present Forty Papers at Globally Recognized Lithography Conference: SUNY Poly CNSE Research Group Awarded Both ‘Best Research Paper’ and ‘Best Research Poster’ at SPIE Advanced Lithography 2015 forum February 25th, 2015

Ultra-thin nanowires can trap electron 'twisters' that disrupt superconductors February 24th, 2015

Silicon Catalyst Announces Partnership With imec to Support Semiconductor Start-Ups February 23rd, 2015

Nanomedicine

Graphene shows potential as novel anti-cancer therapeutic strategy: University of Manchester scientists have used graphene to target and neutralise cancer stem cells while not harming other cells February 26th, 2015

Cutting-edge technology optimizes cancer therapy with nanomedicine drug combinations: UCLA bioengineers develop platform that offers personalized approach to treatment February 24th, 2015

Optical nanoantennas set the stage for a NEMS lab-on-a-chip revolution February 24th, 2015

Together, nanotechnology and genetic interference may tackle 'untreatable' brain tumors: Tel Aviv University researchers' groundbreaking strategy stops brain tumor cell proliferation with targeted nanoparticles February 24th, 2015

Announcements

Maximum Precision in 3D Printing: New complete solution makes additive manufacturing standard for microfabrication February 26th, 2015

Real-time observation of bond formation by using femtosecond X-ray liquidography February 26th, 2015

Bruker-Sponsored Sixth AFM BioMed Conference Highlights Increasing Impact of AFM in Biological Applications February 26th, 2015

Graphene shows potential as novel anti-cancer therapeutic strategy: University of Manchester scientists have used graphene to target and neutralise cancer stem cells while not harming other cells February 26th, 2015

Photonics/Optics/Lasers

Rice's Stephan Link honored for nanoscience research: The Welch Foundation honors ‘rising star’ with $100,000 Hackerman Award February 26th, 2015

Maximum Precision in 3D Printing: New complete solution makes additive manufacturing standard for microfabrication February 26th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

Optical nanoantennas set the stage for a NEMS lab-on-a-chip revolution February 24th, 2015

Research partnerships

European roadmap for graphene science and technology published February 25th, 2015

KIT Increases Commitment in Asia: DAAD Funds Two New Projects: Strategic Partnerships with Chinese Universities and Communi-cation Technologies Network February 22nd, 2015

Increasing Efficiency of Cooling Devices in Oil, Gas Industries February 21st, 2015

Perfect colors, captured with one ultra-thin lens: No need for color correction -- Harvard physicists' flat optics, using nanotechnology, get it right the first time February 19th, 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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE