Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Let there be light: Chemists develop magnetically responsive liquid crystals - UC Riverside discovery has applications in signage, posters, writing tablets, billboards and anti-counterfeit technology

Top: Scheme showing magnetic control over light transmittance in the novel liquid crystals. B is the alternating magnetic field. The polarized light is seen in yellow. The gray rods represent the polarizers. The magnetic field controls the orientation of the nanorods (seen in orange), which in turn affects the polarization of the light and, then, the amount of light that can pass through the polarizers. Bottom: Images show how a polarization-modulated pattern changes darkness/brightness by rotating the direction of the cross polarizers. The circles and background contain magnetic nanorods aligned at different orientations. Research by the Yin Lab at UC Riverside shows that by combining magnetic alignment and lithography processes, it is possible to create patterns of different polarizations in a thin composite film and control over the transmittance of light in particular areas.

Credit: Yin Lab, UC Riverside.
Top: Scheme showing magnetic control over light transmittance in the novel liquid crystals. B is the alternating magnetic field. The polarized light is seen in yellow. The gray rods represent the polarizers. The magnetic field controls the orientation of the nanorods (seen in orange), which in turn affects the polarization of the light and, then, the amount of light that can pass through the polarizers. Bottom: Images show how a polarization-modulated pattern changes darkness/brightness by rotating the direction of the cross polarizers. The circles and background contain magnetic nanorods aligned at different orientations. Research by the Yin Lab at UC Riverside shows that by combining magnetic alignment and lithography processes, it is possible to create patterns of different polarizations in a thin composite film and control over the transmittance of light in particular areas.

Credit: Yin Lab, UC Riverside.

Abstract:
Chemists at the University of California, Riverside have constructed liquid crystals with optical properties that can be instantly and reversibly controlled by an external magnetic field. The research paves the way for novel display applications relying on the instantaneous and contactless nature of magnetic manipulation-such as signage, posters, writing tablets, and billboards.

Let there be light: Chemists develop magnetically responsive liquid crystals - UC Riverside discovery has applications in signage, posters, writing tablets, billboards and anti-counterfeit technology

Riverside, CA | Posted on June 26th, 2014

Commercially available liquid crystals, used in modern electronic displays, are composed of rod-like or plate-like molecules. When an electric field is applied, the molecules rotate and align themselves along the field direction, resulting in a rapid tuning of transmitted light.

"The liquid crystals we developed are essentially a liquid dispersion, a simple aqueous dispersion of magnetic nanorods," said Yadong Yin, an associate professor of chemistry, who led the research project. "We use magnetic nanorods in place of the commercial nonmagnetic rod-like molecules. Optically these magnetic rods work in a similar way to commercial rod-like molecules, with the added advantage of being able to respond rapidly to external magnetic fields."

Yin explained that upon the application of a magnetic field, the nanorods spontaneously rotate and realign themselves parallel to the field direction, and influence the transmittance of polarized light.

Study results appear online in Nano Letters. How light passing through the magnetic liquid crystal is controlled simply by altering the direction of an external magnetic field can be seen here and here.

The magnetically actuated liquid crystals developed by the Yin Lab have several unique advantages. First, they can be operated remotely by an external magnetic field, with no electrodes needed. (Electrical switching of commercial liquid crystals requires transparent electrodes which are very expensive to make.) Second, the nanorods are much larger than the molecules used in commercial liquid crystals. As a result, their orientation can be conveniently fixed by solidifying the dispersing matrix.

Further, the magnetic nanorods can be used to produce thin-film liquid crystals, the orientation of which can be fixed entirely or in just selected areas by combining magnetic alignment and lithographic processes. This allows patterns of different polarizations to be created as well as control over the transmittance of polarized light in select areas.

"Such a thin film does not display visual information under normal light, but shows high contrast patterns under polarized light, making it immediately very useful for anti-counterfeit applications," Yin said. "This is not possible with commercial liquid crystals. In addition, the materials involved in our magnetic liquid crystals are made of iron oxide and silica, which are much cheaper and more eco-friendly than the commercial organic molecules-based liquid crystals."

The liquid crystals may also find applications as optical modulators— optical communication devices for controlling the amplitude, phase, polarization, propagation direction of light.

The discovery came about when Yin's lab first had the idea of using magnetic nanorods to replace rod-shaped molecules in commercial systems to produce liquid crystals that can be magnetically controlled. After looking into the literature, the research team realized that the main challenge in producing practically useful magnetic liquid crystals was in the synthesis of magnetic nanorods.

"Prior attempts had been limited to materials with very limited magnetic responses," Yin said. "We utilized our expertise in colloidal nanostructure synthesis to produce magnetite nanorods that can form liquid crystals and respond strongly to even very weak magnetic fields - even a fridge magnet can operate our liquid crystals."

###

The research was supported by grants to Yin by the National Science Foundation and the U.S. Army Research Laboratory.

Yin was joined in the research by Mingsheng Wang and Le He at UCR; and Serkan Zorba at Whittier College, Calif.

The UCR Office of Technology Commercialization has filed a patent on the technology reported in the research paper.

####

About University of California - Riverside
The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 21,000 students. The campus opened a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of more than $1 billion. A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. UCR also has ISDN for radio interviews. To learn more, call (951) UCR-NEWS.

For more information, please click here

Contacts:
Iqbal Pittalwala

951-827-6050

Copyright © University of California - Riverside

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

Haydale Secures Exclusive Development and Supply Agreement with Tantec A/S: New reactors to be built and commissioned by Tantec A/S represent another step forward towards the commercialisation of graphene October 24th, 2014

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

MEMS & Sensors Technology Showcase: Finalists Announced for MEMS Executive Congress US 2014 October 23rd, 2014

Nanoparticle technology triples the production of biogas October 23rd, 2014

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

Videos/Movies

Novel Rocket Design Flight Tested: New Rocket Propellant and Motor Design Offers High Performance and Safety October 23rd, 2014

Ucore's McKenzie to Deliver Presentation to Rare Earths Conference in Singapore as Highlight of Fall 2014 Marketplace Schedule October 19th, 2014

Display technology/LEDs/SS Lighting/OLEDs

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

QD Vision Wins Prestigious Presidential Green Chemistry Challenge Award from the U.S. Environmental Protection Agency October 16th, 2014

Beyond LEDs: Brighter, new energy-saving flat panel lights based on carbon nanotubes - Planar light source using a phosphor screen with highly crystalline single-walled carbon nanotubes (SWCNTs) as field emitters demonstrates its potential for energy-efficient lighting device October 14th, 2014

Law enforcement/Anti-Counterfeiting/Security/Loss prevention

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

IRLYNX and CEA-Leti to Streamline New CMOS-based Infrared Sensing Modules Dedicated to Human-activities Characterization October 15th, 2014

Discoveries

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

Iranian, Malaysian Scientists Study Nanophotocatalysts for Water Purification October 23rd, 2014

Nanoparticle technology triples the production of biogas October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Announcements

Haydale Secures Exclusive Development and Supply Agreement with Tantec A/S: New reactors to be built and commissioned by Tantec A/S represent another step forward towards the commercialisation of graphene October 24th, 2014

QuantumWise guides the semiconductor industry towards the atomic scale October 24th, 2014

Advancing thin film research with nanostructured AZO: Innovnano’s unique and cost-effective AZO sputtering targets for the production of transparent conducting oxides October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 2014

Iranian Scientists Apply Nanotechnology to Produce Surgery Suture October 23rd, 2014

Iranian, Malaysian Scientists Study Nanophotocatalysts for Water Purification October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

Patents/IP/Tech Transfer/Licensing

Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014

Nanodevices for clinical diagnostic with potential for the international market: The development is based on optical principles and provides precision and allows saving vital time for the patient October 15th, 2014

Aculon Receives Patent for Application of Enhanced Bonding Layers on Titanium October 9th, 2014

harmaEngine will join Nanobiotix’ pivotal trial for NBTXR3 in Soft Tissue Sarcoma to accelerate its development in Asia-Pacific: PharmaEngine to make milestone payment to Nanobiotix in October 2014 to recognize the value created October 8th, 2014

Military

NanoTechnology for Defense (NT4D) October 22nd, 2014

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

1980s aircraft helps quantum technology take flight October 20th, 2014

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 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE