Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Turning Waste Heat Into Power

A "forest" of molecules holds the promise of turning waste heat into electricity. UA physicists discovered that because of quantum effects, electron waves traveling along the backbone of each molecule interfere with each other, leading to the buildup of a voltage between the hot and cold electrodes (the golden structures on the bottom and top). (Rendering by Justin Bergfield)
A "forest" of molecules holds the promise of turning waste heat into electricity. UA physicists discovered that because of quantum effects, electron waves traveling along the backbone of each molecule interfere with each other, leading to the buildup of a voltage between the hot and cold electrodes (the golden structures on the bottom and top). (Rendering by Justin Bergfield)

Abstract:
UA physicists have discovered a new way of harvesting waste heat and turning it into electrical power. Taking advantage of quantum effects, the technology holds great promise for making cars, power plants, factories and solar panels more efficient.

By Daniel Stolte, University Communications

Turning Waste Heat Into Power

Tucson, AZ | Posted on October 2nd, 2010

What do a car engine, a power plant, a factory and a solar panel have in common? They all generate heat - a lot of which is wasted.

University of Arizona physicists have discovered a new way of harvesting waste heat and turning it into electrical power.

Using a theoretical model of a so-called molecular thermoelectric device, the technology holds great promise for making cars, power plants, factories and solar panels more efficient, to name a few possible applications. In addition, more efficient thermoelectric materials would make ozone-depleting chlorofluorocarbons, or CFCs, obsolete.

The research group led by Charles Stafford, associate professor of physics, published its findings in the September issue of the scientific journal, ACS Nano.

"Thermoelectricity makes it possible to cleanly convert heat directly into electrical energy in a device with no moving parts," said lead author Justin Bergfield, a doctoral candidate in the UA College of Optical Sciences.

"Our colleagues in the field tell us they are pretty confident that the devices we have designed on the computer can be built with the characteristics that we see in our simulations."

"We anticipate the thermoelectric voltage using our design to be about 100 times larger than what others have achieved in the lab," Stafford added.

Catching the energy lost through waste heat has been on the wish list of engineers for a long time but, so far, a concept for replacing existing devices that is both more efficient and economically competitive has been lacking.

Unlike existing heat-conversion devices such as refrigerators and steam turbines, the devices of Bergfield and Stafford require no mechanics and no ozone-depleting chemicals. Instead, a rubber-like polymer sandwiched between two metals acting as electrodes can do the trick.

Car or factory exhaust pipes could be coated with the material, less than 1 millionth of an inch thick, to harvest energy otherwise lost as heat and generate electricity.

The physicists take advantage of the laws of quantum physics, a realm not typically tapped into when engineering power-generating technology. To the uninitiated, the laws of quantum physics appear to fly in the face of how things are "supposed" to behave.

The key to the technology lies in a quantum law physicists call wave-particle duality: Tiny objects such as electrons can behave either as a wave or as a particle.

"In a sense, an electron is like a red sports car," Bergfield said. "The sports car is both a car and it's red, just as the electron is both a particle and a wave. The two are properties of the same thing. Electrons are just less obvious to us than sports cars."

Bergfield and Stafford discovered the potential for converting heat into electricity when they studied polyphenyl ethers, molecules that spontaneously aggregate into polymers, long chains of repeating units. The backbone of each polyphenyl ether molecule consists of a chain of benzene rings, which in turn are built from carbon atoms. The chain link structure of each molecule acts as a "molecular wire" through which electrons can travel.

"We had both worked with these molecules before and thought about using them for a thermoelectric device," Bergfield said, "but we hadn't really found anything special about them until Michelle Solis, an undergrad who worked on independent study in the lab, discovered that, low and behold, these things had a special feature."

Using computer simulations, Bergfield then "grew" a forest of molecules sandwiched between two electrodes and exposed the array to a simulated heat source.

"As you increase the number of benzene rings in each molecule, you increase the power generated," Bergfield said.

The secret to the molecules' capability to turn heat into power lies in their structure: Like water reaching a fork in a river, the flow of electrons along the molecule is split in two once it encounters a benzene ring, with one flow of electrons following along each arm of the ring.

Bergfield designed the benzene ring circuit in such a way that in one path the electron is forced to travel a longer distance around the ring than the other. This causes the two electron waves to be out of phase once they reunite upon reaching the far side of the benzene ring. When the waves meet, they cancel each other out in a process known as quantum interference. When a temperature difference is placed across the circuit, this interruption in the flow of electric charge leads to the buildup of an electric potential - voltage - between the two electrodes.

Wave interference is a concept exploited by noise-cancelling headphones: Incoming sound waves are met with counter waves generated by the device, wiping out the offending noise.

"We are the first to harness the wave nature of the electron and develop a concept to turn it into usable energy," Stafford said.

Analogous to solid state versus spinning hard drive type computer memory, the UA-designed thermoelectric devices require no moving parts. By design, they are self-contained, easier to manufacture and easier to maintain compared to currently available technology.

"You could just take a pair of metal electrodes and paint them with a single layer of these molecules," Bergfield said. "That would give you a little sandwich that would act as your thermoelectric device. With a solid-state device you don't need cooling agents, you don't need liquid nitrogen shipments, and you don't need to do a lot of maintenance."

"You could say, instead of Freon gas, we use electron gas," Stafford added.

"The effects we see are not unique to the molecules we used in our simulation," Bergfield said. "Any quantum-scale device where you have a cancellation of electric charge will do the trick, as long as there is a temperature difference. The greater the temperature difference, the more power you can generate."

Molecular thermoelectric devices could help solve an issue currently plaguing photovoltaic cells harvesting energy from sunlight.

"Solar panels get very hot and their efficiency goes down," Stafford said. "You could harvest some of that heat and use it to generate additional electricity while simultaneously cooling the panel and making its own photovoltaic process more efficient."

"With a very efficient thermoelectric device based on our design, you could power about 200 100-Watt light bulbs using the waste heat of an automobile," he said. "Put another way, one could increase the car's efficiency by well over 25 percent, which would be ideal for a hybrid since it already uses an electrical motor."

So, next time you watch a red sports car zip by, think of the hidden power of the electron and how much more efficient that sports car could be with a thermoelectric device wrapped around its exhaust pipe.

Reference: Giant Thermoelectric Effect from Transmission Supernodes. Justin Bergfield, Michelle Solis, and Charles Stafford. ACS Nano Sept. 2010.

Funding for this research was provided by the UA physics department.

####

For more information, please click here

Copyright © University of Arizona

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

Nanosensors could help determine tumors’ ability to remodel tissue: Measuring enzyme levels could help doctors select appropriate treatments September 29th, 2016

Innovation in Nanotechnology is Focus of Symposium: Annual event brings international experts to Northwestern Oct. 6 September 29th, 2016

Cambrios at CEATEC - Japan 2016 September 29th, 2016

Picosun patents ALD nanolaminate to prevent electronics from overheating September 28th, 2016

Physics

New breed of optical soliton wave discovered September 9th, 2016

NREL discovery creates future opportunity in quantum computing: Research into perovskites looks beyond material's usage for efficient solar cells September 9th, 2016

Location matters in the self-assembly of nanoclusters: Iowa State University scientists have developed a new formulation to explain an aspect of the self-assembly of nanoclusters on surfaces that has broad applications for nanotechnology September 8th, 2016

University of Akron researchers find thin layers of water can become ice-like at room temperature: Results could lead to an assortment of anti-friction solutions August 30th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

PHENOMEN is a FET-Open Research Project aiming to lay the foundations a new information technology September 19th, 2016

NIST Patents Single-Photon Detector for Potential Encryption and Sensing Apps September 16th, 2016

Possible Futures

Nanosensors could help determine tumors’ ability to remodel tissue: Measuring enzyme levels could help doctors select appropriate treatments September 29th, 2016

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Researchers at the Catalan Institute of Nanoscience and Nanotechnology show that bending semiconductors generates electricity September 26th, 2016

Chains of nanogold – forged with atomic precision September 23rd, 2016

Academic/Education

PHENOMEN is a FET-Open Research Project aiming to lay the foundations a new information technology September 19th, 2016

AIM Photonics Announces Release of Process Design Kit (PDK) for Integrated Silicon Photonics Design August 25th, 2016

Nanotech Security Featured by Simon Fraser University: Company's Anti-Counterfeiting Technology Developed With the Help of University's 4D LABS Materials Research Institute August 21st, 2016

W.M. Keck Foundation awards Cal State LA a $375,000 research and education grant August 4th, 2016

Discoveries

Nanosensors could help determine tumors’ ability to remodel tissue: Measuring enzyme levels could help doctors select appropriate treatments September 29th, 2016

Fighting cancer with sticky nanoparticles September 27th, 2016

Gold nanoparticles conjugated quercetin inhibits epithelial-mesenchymal transition, angiogenesis and invasiveness via EGFR/VEGFR-2 mediated pathway in breast cancer September 27th, 2016

UNAM develops successful nano edible coating which increases life food September 27th, 2016

Announcements

Nanosensors could help determine tumors’ ability to remodel tissue: Measuring enzyme levels could help doctors select appropriate treatments September 29th, 2016

Innovation in Nanotechnology is Focus of Symposium: Annual event brings international experts to Northwestern Oct. 6 September 29th, 2016

Cambrios at CEATEC - Japan 2016 September 29th, 2016

Picosun patents ALD nanolaminate to prevent electronics from overheating September 28th, 2016

Automotive/Transportation

Carbon-coated iron catalyst structure could lead to more-active fuel cells September 15th, 2016

GLOBALFOUNDRIES Launches Embedded MRAM on 22FDX® Platform: High-performance embedded non-volatile memory solution is ideally suited for emerging applications in advanced IoT and automotive September 15th, 2016

GLOBALFOUNDRIES Extends FDX™ Roadmap with 12nm FD-SOI Technology: 12FDXTM delivers full-node scaling, ultra-low power, and software-controlled performance on demand September 8th, 2016

Imperial College use Kleindiek micromanipulators in their research into electrochemical energy devices September 6th, 2016

Industrial

UNAM develops successful nano edible coating which increases life food September 27th, 2016

Mathematical nanotoxicoproteomics: Quantitative characterization of effects of multi-walled carbon nanotubes: This research article by Dr. Subhash Basak et al. will be published in Current Computer-Aided Drug Design, Volume 12, 2016 September 2nd, 2016

New flexible material can make any window 'smart' August 23rd, 2016

Industrial Nanotech, Inc. Provides Shareholder Update August 22nd, 2016

Solar/Photovoltaic

Cambrios at CEATEC - Japan 2016 September 29th, 2016

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Semiconducting inorganic double helix: New flexible semiconductor for electronics, solar technology and photo catalysis September 15th, 2016

New perovskite research discoveries may lead to solar cell, LED advances September 12th, 2016

Quantum nanoscience

Chains of nanogold – forged with atomic precision September 23rd, 2016

Notre Dame researchers find transition point in semiconductor nanomaterials September 6th, 2016

NREL Discovery Creates Future Opportunity in Quantum Computing: Research into perovskites looks beyond material’s usage for efficient solar cells September 1st, 2016

Light and matter merge in quantum coupling: Rice University physicists probe photon-electron interactions in vacuum cavity experiments August 24th, 2016

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







Car Brands
Buy website traffic