Nanotech: Hot Technology Gets a Cool Down

June 3, 2008

It’s the hottest technology – featherweight laptops that feature rapid response, crisp graphics and operate complex computer games; slim cell phones with Web-browsing capabilities, store high resolution photos and keep track of our lives; credit card-sized MP3 players that store thousands of songs and hours of videos.

But as those gadgets get smaller, more portable, and are asked to do more, they are getting hotter – as in overheating. Electronic appliances that once were large enough to be cooled by fans are now in danger of malfunctioning because there is no easy way to remove all the excess heat produces by large numbers of tiny transistors operating inside them.

“It’s a major problem that could limit the ability to make all electronics smaller and at the same time faster and more powerful,” said Alexander Balandin, a UCR professor of electrical engineering.

To that end, Balandin recently received a $600,000 grant to help devise such technology. The three-year project, funded by the Air Force Office of Scientific Research (AFOSR), aims to increase the speed of the next generation of electronic and optoelectronic devices while simultaneously reducing heat dissipation and improving thermal management.

Balandin work in this area focuses on phonon engineering, an area of research that he pioneered more than a decade ago.

In tech talk, acoustic phonons are quantized modes of crystal lattice vibrations, which limit electrical conductivity of semiconductors while, at the same time, carry heat in semiconductors and electrical insulators. Optical phonons strongly influence the light emission properties of materials. Nanometer scale dimensions of the state-of-the-art semiconductor devices and a wide variety of available constituent materials allow one to tune the phonon energy dispersion and, thus, control the ways phonons interact with electrons and other phonons.

The methods of controlling the acoustic phonon interaction with electrons may have a strong impact on how much heat is generated in electronic and optoelectronic devices. Examples of optoelectronic devices include light-emitting diodes (LEDs) used in color displays and traffic lights; photodetectors essential for light-wave long-distance telecommunications; semiconductor lasers widely utilized in medical instrumentation, digital data storage, material processing and safety equipment. As these devices continue to be made smaller and the amount of dissipated power per unit area increases their cooling becomes crucial for continuous use.

Balandin uses the following analogy to describe the motion of electrons through a transistor: A large group of students wearing blue T-shirts – they are the electrons – must, quickly and efficiently, move into a room through one door and out of the room through another door located on the other side of the room. Students in red T-shirts – they are the phonons – are in the room bumping into the blue T-shirt students and – occasionally – the walls of the room. As the size of the room decreases things get more chaotic with more bumping (e.g. scattering in scientific terms). The resulting effect is decreased ability of electrons to move through the transistor channel and increased temperature.

Balandin and his researchers will investigate the use of layers of synthetic diamond incorporated with the conventional silicon layers to better manage the interaction of phonons and electrons. Diamond is known to be an excellent thermal conductor and its use in device structures for increasing electron mobility will simultaneously improve the heat removal.

Balandin is the director of the Nano-Device Laboratory, which conducts experimental and theoretical research aimed at better understanding phonons in novel materials, nanostructures and devices.

Source: University of California, Riverside

3.7 /5 (14 votes)  

Rank 3.7 /5 (14 votes)
Tags

Relevant PhysicsForums posts
  • what is electricity???
    created4 hours ago
  • Can Plasma Be Solid
    created4 hours ago
  • What is delta Δ ?
    created5 hours ago
  • Need some help understanding Hertz–Knudsen formula
    created5 hours ago
  • Anatomy of Fat man: implosion-critical bomb
    created7 hours ago
  • what makes two sounds similar???
    created8 hours ago
  • More from Physics Forums - General Physics

More news stories

Lab study raises questions over nano-particle impact

Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.

Nanotechnology / Bio & Medicine

created 9 hours ago | popularity 5 / 5 (6) | comments 0

New kind of solar cell could capture significantly more energy than current cells

New solar cells could increase the maximum efficiency of solar panels by over 25%, according to scientists from the University of Cambridge.

Nanotechnology / Nanophysics

created Feb 08, 2012 | popularity 4.5 / 5 (13) | comments 14 | with audio podcast

Nanoshell whispering galleries improve thin solar panels

Visitors to Statuary Hall in the U.S. Capitol Building may have experienced a curious acoustic feature that allows a person to whisper softly at one side of the cavernous, half-domed room and for another on ...

Nanotechnology / Nanomaterials

created Feb 07, 2012 | popularity 4.4 / 5 (7) | comments 6 | with audio podcast

'Dark plasmons' transmit energy

Microscopic channels of gold nanoparticles have the ability to transmit electromagnetic energy that starts as light and propagates via "dark plasmons," according to researchers at Rice University.

Nanotechnology / Nanophysics

created Feb 09, 2012 | popularity 4.8 / 5 (10) | comments 1 | with audio podcast

Revealing how a battery material works

Since its discovery 15 years ago, lithium iron phosphate (LiFePO4) has become one of the most promising materials for rechargeable batteries because of its stability, durability, safety and ability to deliver ...

Nanotechnology / Nanomaterials

created Feb 08, 2012 | popularity 5 / 5 (6) | comments 0 | with audio podcast


Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy

For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...

New method to examine batteries -- MRI from the inside

There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...

Google might launch Drive for cloud storage soon

(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...

A mitosis mystery solved: How chromosomes align perfectly in a dividing cell

Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...

Starve a virus, feed a cure? Findings show how some cells protect themselves against HIV

A protein that protects some of our immune cells from the most common and virulent form of HIV works by starving the virus of the molecular building blocks that it needs to replicate, according to research published online ...

Researchers find extensive RNA editing in human transcriptome

In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...