Using Nanowire Silicon Thermoelectrics to Capture Waste Heat
January 21, 2008 3:17 AM
Professor Peidong Yang led the University of California, Berkley team who discovered silicon nanowire's thermoelectric properties.
(Source: University of California, Berkley)
A scanning electron microscope image of a thin silicon nanowire stretching between two heating pads, one as a heat source, the other as a sensor.
(Source: A. Hochbaum)
Silicon heat capture could allow cheap refrigeration and energy saving
Among the many valuable properties of silicon is its ability to
capture solar energy
to create electricity via its photoelectric character. Now scientists are discovering that silicon, when properly prepared, can form a very good thermoelectric as well. This opens the door to a plethora of uses, including refrigeration, solar heat power generation, and power generation from other heat sources, such as computer waste heat or car heat.
has two basic modes of operation. When a thermoelectric is placed over a heat gradient, it generates an electric current. The other mode is the reverse; when a thermoelectric is exposed to an electric current, it creates a heat difference, cooling one side of it, and warming the other side. Thus thermoelectrics are applicable to power generation, refrigeration and heating.
Traditional thermoelectrics, which have been around since the 1960s, rely on either bismuth telluride or lead telluride. These materials are relatively expensive due to scarcity and lack of a large manufacturing infrastructure. They are also bulky and require more material, which further increaese their cost. While thermoelectric coolers have achieved modest commercial usage in seat coolers and picnic coolers, they have yet to realize their full potential.
may change that. Professor Peidong Yang and his colleagues at the University of California, Berkley published in last week's
journal the results of years of research into using silicon as thermoelectrics. Their results show that silicon can be a viable thermoelectric.
The key is in the preparation. The researchers prepared thin nanowires of silicon. When these wires are exposed to a temperature difference, they generate electricity. Standard silicon is a poor thermoelectric, but according to Dr. Yang, "the performance of the nanowires is already comparable to the best existing thermoelectric material."
A good thermoelectric needs to have two key properties -- good electrical conduction, and poor heat conduction. Silicon typically conducts both very well, but by producing 50 nm nanowires, the heat conduction of silicon is reduced to one hundreth of its normal levels, while electrical conduction remains unchanged. The material is comparable to commercial thermoelectrics.
Two possible uses of the technology are to generate electricity from waste heat of car engines. Current thermoelectrics are too expensive and large to make this a practical possibility. Nanowire silicon layers, though could provide a means to recapture some of the energy lost to heat during the conversion to mechanical energy in a car engine. This extra savings could be stored in batteries, to give next generation electric vehicles, such as
the Chevrolet Volt
, even better efficiency.
It could also find a home in solar power cells. By coupling it with traditional photoelectric cells, much higher efficiencies could possibly be reached. Yet another application is to put the materials in computers to provide energy savings, which would be particularly valuable to mobile computing. Further, it could be used in refrigeration applications, as well.
Much work needs to be done before the process is perfected. The physics behind why nanowires of silicon lose their heat conduction is not understood, which stands in the way of refining the efficiency of this class of devices. Further creating a thermoelectric on the macroscopic scale, by creating a network of nanowires, has yet to be accomplished. Still, the discovery of these properties in silicon promise a way to eventually use replace current less ideal thermoelectrics with an abundant material with a large processing infrastructure.
"If they're going to pirate somebody, we want it to be us rather than somebody else." -- Microsoft Business Group President Jeff Raikes
GM Adds Wiggle Room to 2010 Volt Deadline
January 4, 2008, 11:18 AM
Promise of Thermoelectric Materials on the Rebound
November 27, 2007, 2:32 PM
Sharp Readying Thin Solar Cell Output For 2008
November 4, 2007, 10:58 AM
PIQ ROBOTTM reveals its new artificial intelligence software
November 29, 2016, 12:59 AM
One more time - Happy Thanksgiving to Everyone Around the World
November 24, 2016, 4:00 AM
Google’s Smart Contact Lens Project gets halted for 2016
November 20, 2016, 7:00 AM
Cell Research Study shows African Americans have greater immune response to infection
November 10, 2016, 1:00 AM
UTHealth Clinical Trial Shows Progress Using Stem Cells to Treat Traumatic Brain Injury
November 8, 2016, 1:00 AM
Uber Partners with Circulation to Pilot Program Connecting Transportation and Digital Health Care
November 6, 2016, 5:00 AM
Most Popular Articles
Surface Pro 5 Rumors - New Release Date and Price
April 22, 2017, 6:45 AM
SAPPHIRE PULSE Radeon RX 580 8GD5 – Great Value for the Money
April 20, 2017, 7:47 AM
Apple Watch NikeLab Limited Edition unveiled.
April 22, 2017, 6:20 AM
Dell Inspiron 17 7000 – A Premium Laptop featuring 7th Gen Intel Core i7 in a 2-in-1 Frame.
April 19, 2017, 7:45 AM
Meet the Smartphone with four cameras - Alcatel Flashphone
April 5, 2017, 11:20 AM
Latest Blog Posts
Google Co-Founder, Sergey Brin has an Airship
Apr 26, 2017, 6:43 AM
Samsung Galaxy S8 and S8 Plus – Lots of Glass that Breaks Easily
Apr 25, 2017, 7:20 AM
Samsung Galaxy S8 – Warning for Pet Owners
Apr 24, 2017, 5:59 AM
Sound Bars and the Costs?
Apr 23, 2017, 6:30 AM
Link your Brain to Your Computer – In Four Years…Maybe
Apr 22, 2017, 7:03 AM
Google Home can now identify users by their voice.
Apr 21, 2017, 7:15 AM
Amazon Lex – Now Available for Developers.
Apr 20, 2017, 6:58 AM
You can now use Instagram offline on your Android Smartphone
Apr 19, 2017, 8:00 AM
Now you can livestream to YouTube from your mobile device.
Apr 18, 2017, 8:05 AM
Google Home – Is It a Spy Device?
Apr 17, 2017, 7:30 AM
Apple added to self –driving test permit list
Apr 15, 2017, 6:21 AM
Project Scorpio – Coming on June 11
Apr 14, 2017, 6:20 AM
Looks Like Samsung Has Been Forgiven.
Apr 13, 2017, 6:50 AM
United Airlines - Blasted on China’s Social Network and the Stock Market
Apr 12, 2017, 6:50 AM
Amazon's Third-Party Sellers Hacked
Apr 11, 2017, 6:25 AM
Microsoft Surface Pro5 Details Revealed
Apr 9, 2017, 6:41 AM
Own An Android Phone? Then you could be hacked over Wi-FI
Apr 7, 2017, 6:47 AM
Apple confirms iOS 10.3 bug and its effect on iCloud Services
Apr 6, 2017, 6:30 AM
Apple Rolls Out New Version of Apple Music
Apr 5, 2017, 10:35 AM
Apple in the News
Apr 4, 2017, 9:03 AM
Apple iPhones Will Soon Feature Graphics Chips Designed BY Apple
Apr 3, 2017, 6:23 AM
More Blog Posts
Copyright 2017 DailyTech LLC. -
Terms, Conditions & Privacy Information