Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Taming Tiny, Unruly Waves for Nano Optics

Taming Tiny, Unruly Waves for Nano Optics

October 09, 2007

Nanoscale devices present a unique challenge to any optical technology - there's just not enough room for light to travel in a straight line.

On the nanoscale, energy may be produced by radiating photons of light between two surfaces very close together (sometimes as close as 10 nanometers), smaller than the wavelength of the light. Light behaves much differently on the nanoscale as its wavelength is interrupted, producing unstable waves called evanescent waves. The direction of these unpredictable waves can't be calculated, so researchers face the daunting task of designing nanotechnologies to work with the tiny, yet potentially useful waves of light.




Researchers at Georgia Tech have discovered a way to predict the behavior of these unruly waves of light during nanoscale radiation heat transfer, opening the door to the design of a spectrum of new nanodevices (or NEMS) and nanotechnologies, including solar thermal energy technologies. Their findings were featured on the cover of the Oct. 8 issue of Applied Physics Letters.

"This discovery gives us the fundamental information to determine things like how far apart plates should be and what size they should be when designing a technology that uses nanoscale radiation heat transfer," said Zhuomin Zhang, a lead researcher on the project and a professor in the Woodruff School of Mechanical Engineering. "Understanding the behavior of light at this scale is the key to designing technologies to take advantage of the unique capabilities of this phenomenon."

The Georgia Tech research team set out to study evanescent waves in nanoscale radiation energy transfer (between two very close surfaces at different temperatures by means of thermal radiation). Because the direction of evanescent waves is seemingly unknowable (an imaginary value) in physics terms, Zhang's group instead decided to follow the direction of the electromagnetic energy flow (also known as a Poynting vector) to predict behavior rather than the direction of the photons.

"We're using classic electrodynamics to explain the behavior of the waves, not quantum mechanics," Zhang said. "We're predicting the energy propagation - and not the actual movement - of the photons."

The challenge is that electrodynamics work differently on the nanoscale and the Georgia Tech team would need to pinpoint those differences. Planck's law, a more than 100-year-old theory about how electromagnetic waves radiate, does not apply on the nanoscale due to fact that the space between surfaces is smaller than a wavelength.

The Georgia Tech team observed that instead of normal straight line radiation, the light was bending as protons tunneled through the vacuum in between the two surfaces just nanometers apart. The team also noticed that the evanescent waves were separating during this thermal process, allowing them to visualize and predict the energy path of the waves.

Understanding the behavior of such waves is critical to the design of many devices that use nanotechnology, including near-field thermophotovoltaic systems, nanoscale imaging based on thermal radiation scanning tunneling microscopy and scanning photon-tunneling microscopy, said Zhang.

Georgia Institute of Technology



Related Nanoscale Current Events and Nanoscale News Articles Nanoscale Current Events and Nanoscale News RSS Nanoscale Current Events and Nanoscale News RSS
Small optical force can budge nanoscale objects
With a bit of leverage, Cornell researchers have used a very tiny beam of light with as little as 1 milliwatt of power to move a silicon structure up to 12 nanometers. That's enough to completely switch the optical properties of the structure from opaque to transparent, they reported.

Small nanoparticles bring big improvement to medical imaging
If you're watching the complex processes in a living cell, it is easy to miss something important-especially if you are watching changes that take a long time to unfold and require high-spatial-resolution imaging.

Pushing light beyond its known limits
Scientists at the University of Adelaide have made a breakthrough that could change the world's thinking on what light is capable of.

Nanotech in Space: Rensselaer Experiment To Weather the Trials of Orbit
Novel nanomaterials developed at Rensselaer Polytechnic Institute are scheduled to blast off into orbit on November 16 aboard Space Shuttle Atlantis.

Caltech scientists develop DNA origami nanoscale breadboards for carbon nanotube circuits
In work that someday may lead to the development of novel types of nanoscale electronic devices, an interdisciplinary team of researchers at the California Institute of Technology (Caltech) has combined DNA's talent for self-assembly with the remarkable electronic properties of carbon nanotubes, thereby suggesting a solution to the long-standing problem of organizing carbon nanotubes into nanoscale electronic circuits.

Engineers image nanostructure of a solid acid catalyst and boost its catalytic activity
The catalytic processes that facilitate the production of many chemicals and fuels could become much more environmentally friendly thanks to a breakthrough achieved by researchers from Lehigh and Rice Universities.

Findings show nanomedicine promising for treating spinal cord injuries
Researchers at Purdue University have discovered a new approach for repairing damaged nerve fibers in spinal cord injuries using nano-spheres that could be injected into the blood shortly after an accident.

Magnetic nanoparticles to simultaneously diagnose, monitor and treat
Whether it's magnetic nanoparticles (mNPs) giving an army of 'therapeutically armed' white blood cells direction to invade a deadly tumour's territory, or the use of mNPs to target specific nerve channels and induce nerve-led behaviour (such as the life-dependant thumping of our hearts), mNPs have come a long way in the past decade.

Breakthrough in industrial-scale nanotube processing
Rice University scientists today unveiled a method for the industrial-scale processing of pure carbon-nanotube fibers that could lead to revolutionary advances in materials science, power distribution and nanoelectronics.

LANL Roadrunner simulates nanoscale material failure
Very tiny wires, called nanowires, made from such metals as silver and gold, may play a crucial role as electrical or mechanical switches in the development of future-generation ultrasmall nanodevices.
More Nanoscale Current Events and Nanoscale News Articles
Nanoscale: Visualizing an Invisible World

Nanoscale: Visualizing an Invisible World
by Kenneth S. Deffeyes (Author), Stephen E. Deffeyes (Author)

The world is made up of structures too small to see with the naked eye, too small to see even with an electron microscope. Einstein established the reality of atoms and molecules in the early 1900s. How can we see a world measured in fractions of nanometers? (Most atoms are less than one nanometer, less than one-billionth of a meter, in diameter.) This beautiful and fascinating book gives us a tour of the invisible nanoscale world. It offers many vivid color illustrations of atomic structures, each accompanied by a short, engagingly written essay. The structures advance from the simple (air, ice) to the complex (supercapacitor, rare earth magnet). Each subject was chosen not in search of comprehensiveness but because it illustrates how atomic structure creates a property (such as...

SpillKlenz

SpillKlenz
by NanoScale Corporation

Odor eliminating liquid absorbent facilitates immediate clean-up of liquids by quickly absorbing spills and neutralizing the accompanying odors.

SpillKlenz Travel Kit

SpillKlenz Travel Kit
by NanoScale Corporation

Odor eliminating liquid absorbent kit facilitates immediate clean-up of liquids by quickly absorbing spills and neutralizing the accompanying odors. The kit provides spill control and containment in confined spaces where clean-up is inconvenient. Kit includes 2 revolutionary odor neutralizing sorbent packets, 2 sanitizing wipes, 2 disposal bags, 1 scoop and scraper, and 1 pair of non-latex gloves.

OdorKlenz Laundry, Medium

OdorKlenz Laundry, Medium
by NanoScale Corporation

OdorKlenz Laundry is an odor elimination laundry additive which eliminates tough odors regular detergents leave behind.

No Small Matter: Science on the Nanoscale

No Small Matter: Science on the Nanoscale
by Felice C. Frankel (Author), George M. Whitesides (Author)

A small revolution is remaking the world. The only problem is, we can’t see it. This book uses dazzling images and evocative descriptions to reveal the virtually invisible realities and possibilities of nanoscience. An introduction to the science and technology of small things, No Small Matter explains science on the nanoscale.

Authors Felice C. Frankel and George M. Whitesides offer an overview of recent scientific advances that have given us our ever-shrinking microtechnology—for instance, an information processor connected by wires only 1,000 atoms wide. They describe the new methods used to study nanostructures, suggest ways of understanding their often bizarre behavior, and outline their uses in technology. This book explains the various means of making...

Nanoscale

Nanoscale
Geordie Haley (Primary Contributor)



Electrical Transport in Nanoscale Systems

Electrical Transport in Nanoscale Systems
by Massimiliano Di Ventra (Author)

This graduate textbook provides an in-depth description of the transport phenomena relevant to systems of nanoscale dimensions. The different theoretical approaches are critically discussed, with emphasis on their basic assumptions and approximations. The book also covers information content in the measurement of currents, the role of initial conditions in establishing a steady state, and the modern use of density-functional theory. Topics are introduced by simple physical arguments, with particular attention to the non-equilibrium statistical nature of electrical conduction, and followed by a detailed formal derivation. This textbook is ideal for graduate students in physics, chemistry, and electrical engineering.

Microscale and Nanoscale Heat Transfer: Fundamentals and Engineering Applications

Microscale and Nanoscale Heat Transfer: Fundamentals and Engineering Applications
by Choondal B. Sobhan (Author), G. P. "Bud" Peterson (Author)

Through analyses, experimental results, and worked-out numerical examples, Microscale and Nanoscale Heat Transfer: Fundamentals and Engineering Applications explores the methods and observations of thermophysical phenomena in size-affected domains. Compiling the most relevant findings from the literature, along with results from their own research activities, the authors provide a useful treatise on the principal concepts and practical design engineering aspects of heat transfer.

The book discusses in detail various modern engineering applications, such as microchannel heat sinks, micro heat exchangers, and micro heat pipes. It covers methods that range from discrete computation to optical measurement techniques for microscale applications. The authors also present the fundamentals...

Nanoscale: Issues and Perspectives for the Nano Century

Nanoscale: Issues and Perspectives for the Nano Century
by Nigel Cameron (Editor), M. Ellen Mitchell (Editor)

An authoritative examination of the present and potential impact of nanoscale science and technology on modern life

Because truly transformative technologies have far-reaching consequences, they always generate controversy. Establishing an effective process for identifying and understanding the broad implications of nanotechnology will advance its acceptance and success, impact the decisions of policymakers and regulatory agencies, and facilitate the development of judicious policy approaches to new technology options.

Nanoscale: Issues and Perspectives for the Nano Century addresses the emerging ethical, legal, policy, business, and social issues. A compilation of provocative treatises, this reference: Covers an area of increasing research and funding ...

Introduction to Nanoscale Science and Technology (Nanostructure Science and Technology)

Introduction to Nanoscale Science and Technology (Nanostructure Science and Technology)
by Massimiliano Di Ventra (Editor), Stephane Evoy (Editor), James R. Heflin (Editor)

Nanoscale science and technology is a young, promising field that encompasses a wide range of disciplines including physics, chemistry, biology, electrical engineering, chemical engineering, and materials science. With rapid advances in areas such as molecular electronics, synthetic biomolecular motors, DNA-based self-assembly, and manipulation of individual atoms, nanotechnology has captured the attention and imagination of researchers and the general public. Introduction to Nanoscale Science and Technology provides a broad and thorough introduction that is aimed specifically at undergraduate seniors and early graduate students in all of the disciplines enumerated above. It will also be of value to academic, industrial, and government researchers interested in a primer in the field. ...

© 2009 BrightSurf.com