(Press-News.org) Washington, D.C. (September 28, 2010) -- The second law of thermodynamics is a big hit with the beret-wearing college crowd because of its implicit existential crunch. The tendency of a closed systems to become increasingly disordered if no energy is added or removed is a popular, if not depressing, "things fall apart" sort-of-law that would seem to confirm the adolescent experience.
Now a joint team of Ukrainian and American scientists has demanded more work and less poetry from the second law of thermodynamics, proposing a novel "pyroelectric" method to power tiny devices using waste heat.
Using tiny structures called ferroelectric nanowires, they can rapidly generate an electrical current in response to any change in the ambient temperature, harvesting otherwise wasted energy from thermal fluctuations. Their report appears in the Journal of Applied Physics, which is published by the American Institute of Physics.
Explains lead researcher Anna Morozovska of the National Academy of Sciences of Ukraine, "The second law of thermodynamics rules modern life: Through all kinds of industry, humans consistently produce an enormous amount of waste heat. However, the laws of thermodynamics do not exclude rescuing some of this energy by harvesting the thermal fluctuations to produce electricity."
Pyroelectrictricity can play key role in consumer electronics, says Morozovska, and recovering this heat in the form of pyroelectric energy may bring about a new era of "tiny energy." Pyroelectric nanogenerators could be extremely useful for powering specific tasks in biological applications, medicine and nanotechnology, particularly in space because they perform well in low temperatures.
In an investigation of the pyroelectric properties of ferroelectric nanowires, the team analyzed how the pyroelectric coefficient corresponds to the radius of the wire and its coupling. They found that the smaller the wire radius, the more the pyroelectric coefficient diverges until a critical radius at which the response changes to paraelectric (above the Curie temperature). This so-called "size effect" could be used to tune the phase transition temperatures in ferroelectric nanostructures, thus enabling a system with a large, tunable, pyroelectric response.
In theory, the use of rectifying contacts could enable the polarized ferroelectric nanowire to generate a giant, pyroelectric, direct current and voltage in response to temperature fluctuations that could be harvested and detected using a bolometric detector. Such a nanoscale device would not contain any moving parts and could be suitable for long-term operation in ambient applications such as in-vitro biological systems and outer space. The researchers calculate that these little nanogenerators would have very high efficiency at low temperatures, decreasing at warmer temperatures.
###
The article, "Pyroelectric response of ferroelectric nanowires: Size effect and electric energy harvesting" by Anna N. Morozovska, Eugene A. Eliseev, George S. Svechnikov, and Sergei V. Kalinin appears in the Journal of Applied Physics. http://jap.aip.org/resource/1/japiau/v108/i4/p042009_s1
About Journal of Applied Physics
Journal of Applied Physics is the American Institute of Physics' (AIP) archival journal for significant new results in applied physics; content is published online daily, collected into two online and printed issues per month (24 issues per year). The journal publishes articles that emphasize understanding of the physics underlying modern technology, but distinguished from technology on the one side and pure physics on the other. See: http://jap.aip.org/
ABOUT AIP
The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world's largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.
END
Washington, D.C. (September 28, 2010) -- A new disposable device based on advances in microfluidics may help identify advanced breast cancer patients who are candidates for therapy with the drug trastuzumab (Herceptin). The device is described in the American Institute of Physics' journal Biomicrofluidics.
Aggressive breast cancers with poor prognosis typically have abnormal levels of the protein HER2 (the tyrosine kinase human epidermal growth factor receptor 2). The new elastomeric, rubber-like device is designed to efficiently capture cancer cells overexpressing HER2 ...
Washington, D.C. (September 28, 2010) -- Polymer-based photovoltaic cells have some real advantages compared to the currently used semiconductor-based cells. They are easy to make and the materials are cheap. The challenge is to figure out how to make efficient cells while keeping the manufacturing cost low.
One approach uses a light-absorbing polymer along with a derivative of a sixty-carbon fullerene molecule, commonly known as a buckyball. For maximum efficiency, the two materials must be present in thin layers near opposite electrodes but most analytical methods ...
Professor Sonia Ghumman from the University of Hawai'i at Mānoa Shidler College of Business has completed an intensive marketing research on the effects of Muslim women who wear hijabs (head scarves) in the U.S.
Ghumman's research examined the expectations that women who wear hijabs have regarding their employment opportunities. "We surveyed 219 American Muslim women on their job seeking experience," said Ghumman. "The findings reveal that Hijabis are not only aware of their stigma of being Muslim, but also expect to be treated differently in the workplace as a result ...
Grand Rapids, Mich. (September 28, 2010) – New findings from Van Andel Research Institute (VARI) scientists could lead to environmentally-friendly sprays that help plants survive drought and other stresses in harsh environments to combat global food shortages. The study is a follow-up to findings published in Nature last year that were named among the top breakthroughs of 2009 by Science magazine.
"I think that the work established the methodologies and feasibilities of finding cheap and environmentally benign chemicals for agricultural application to improve the water ...
A global temperature increase of up to 4.2 º C and the end of coral reefs could become reality by 2100 if national targets are not revised in the Copenhagen Accord, the international pledge which was agreed at last year's Copenhagen's COP15 climate change conference.
Just ahead of the next United Nations Climate Change Conference, which starts on 4 October in Tianjin, China, a new report published today, Wednesday, 29 September, in IOP Publishing's Environmental Research Letters describes how, due to lack of global action to date, only a small chance remains for keeping ...
In a recently published study in the journal Addiction, researchers from Bowling Green State University report evidence of an association between father's incarceration and substantially elevated risks for illegal drug use in adolescence and early adulthood.
The number of persons incarcerated in the United States has sharply risen over the past several decades, from about 250,000 in 1975 to 2,250,000 in 2006. So too has the number of children with incarcerated parents, particularly fathers. The consequences of father's incarceration for their children, families, and communities ...
ANN ARBOR, Mich.---Twelve years ago, then 28-year-old graduate student Brian Zikmund-Fisher was forced into the toughest choice of his life: Die from a blood disorder within a few years or endure a bone marrow transplant that could cure him or kill him in weeks.
Zikmund-Fisher, now an assistant professor at the University of Michigan School of Public Health specializing in health communication, chose to gamble. After nine months of blood transfusions, a bone marrow match was found in Australia. Zikmund-Fisher spent another month in isolation until his new immune system ...
Home owners using the new Solar Home Loan Calculator can determine how to leverage their home equity to install solar power and gain a secure and cheap power source, said ZEN Home Energy Systems Chief Executive Officer, Richard Turner.
"We've known for some time now it is cheaper to produce your own energy at home than buy, but one of the biggest barriers facing householders is finding the cash to finance installation of a whole home solar energy system," Mr Turner said.
"Currently the only other solar funding alternatives in the market are consumer finance packages ...
Professor Ewart Keep. ESRC Centre on Skills, Knowledge and Organisational Performance (SKOPE). Professor Ewart Keep's research interests include the links between skills and economic performance (broadly defined), the education and training policy formation process, employers' perceptions of training and the factors that influence their willingness to invest in skills, 14-19 vocational education and training, higher education policy and the graduate labour market, lifelong learning, and the linkages between skills and people management issues.
Dr Scott Hurrell. University ...
It is 88 days before Christmas and Warplanes is throwing away an early Christmas gift for all their Facebook fans and Twitter followers! They are giving away beautiful hand-made models of the F-15E Strike Eagle, F-16 Fighting Falcon and an Apache Longbow AH-64D through their blogging and twitting contest.
"Blog, Grab and Brag" Warplanes.com's Win a Model Airplane Contest are for Facebook fanatics and bloggers. To join, one must post a blog article stating the reason(s) on why he/she should win. A link to the entry should be posted on Warplanes' fan page wall. Started ...
