(Press-News.org) By combining 3D holographic lithography and 2D photolithography, researchers from the University of Illinois at Urbana-Champaign have demonstrated a high-performance 3D microbattery suitable for large-scale on-chip integration with microelectronic devices.
"This 3D microbattery has exceptional performance and scalability, and we think it will be of importance for many applications," explained Paul Braun, a professor of materials science and engineering at Illinois. "Micro-scale devices typically utilize power supplied off-chip because of difficulties in miniaturizing energy storage technologies. A miniaturized high-energy and high-power on-chip battery would be highly desirable for applications including autonomous microscale actuators, distributed wireless sensors and transmitters, monitors, and portable and implantable medical devices."
"Due to the complexity of 3D electrodes, it is generally difficult to realize such batteries, let alone the possibility of on-chip integration and scaling. In this project, we developed an effective method to make high-performance 3D lithium-ion microbatteries using processes that are highly compatible with the fabrication of microelectronics," stated Hailong Ning, a graduate student in the Department of Materials Science and Engineering and first author of the article, "Holographic Patterning of High Performance on-chip 3D Lithium-ion Microbatteries," appearing in Proceedings of the National Academy of Sciences.
"We utilized 3D holographic lithography to define the interior structure of electrodes and 2D photolithography to create the desired electrode shape." Ning added. "This work merges important concepts in fabrication, characterization, and modeling, showing that the energy and power of the microbattery are strongly related to the structural parameters of the electrodes such as size, shape, surface area, porosity, and tortuosity. A significant strength of this new method is that these parameters can be easily controlled during lithography steps, which offers unique flexibility for designing next-generation on-chip energy storage devices."
Enabled by a 3D holographic patterning technique--where multiple optical beams interfere inside the photoresist creating a desirable 3D structure--the battery possesses well-defined, periodically structured porous electrodes, that facilitates the fast transports of electrons and ions inside the battery, offering supercapacitor-like power.
"Although accurate control on the interfering optical beams is required to construct 3D holographic lithography, recent advances have significantly simplified the required optics, enabling creation of structures via a single incident beam and standard photoresist processing. This makes it highly scalable and compatible with microfabrication," stated John Rogers, a professor of materials science and engineering, who has worked with Braun and his team to develop the technology.
"Micro-engineered battery architectures, combined with high energy material such as tin, offer exciting new battery features including high energy capacity and good cycle lives, which provide the ability to power practical devices," stated William King, a professor of mechanical science and engineering, who is a co-author of this work.
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The research is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering through the Frederick Seitz Materials Research Laboratory at Illinois. In addition to Ning, Braun, Rogers, and King, study co-authors include graduate students, James H. Pikul, Runyu Zhang, Xuejiao Li, Sheng Xu, and Junjie Wang.
U.S. Congress approval ratings are at record lows. Now a new study suggests that this may be partly due to a decline in the use of warm, agreeable language in the House.
The study, co-authored by University of British Columbia business professor Karl Aquino, found that the use of prosocial words -- language such as cooperate or contribute -- by lawmakers predicts public approval of Congress six months later.
"If members of Congress want to be viewed more positively by the public, it appears that the words they use matter," says Aquino, a marketing and behavioural science ...
Researchers report that as the world population increases and food demand has grown, globalization of trade has made the food supply more sensitive to environmental and market fluctuations. This leads to greater chances of food crises, particularly in nations where land and water resources are scarce and therefore food security strongly relies on imports.
The study assesses the food supply available to more than 140 nations (with populations greater than 1 million) and demonstrates that food security is becoming increasingly susceptible to perturbations in demographic ...
(MEMPHIS, Tenn. - May 11, 2015) Childhood cancer survivors - especially those whose treatment included brain irradiation or chemotherapy with glucocorticoids - are 14 percent more likely to be obese than their healthy peers. The St. Jude Children's Research Hospital study appears today in the journal Cancer.
Of the 1,996 childhood cancer survivors in this study, 36.2 percent had a body mass index (BMI) of 30 kilograms per meters squared or more, which qualifies as obese. That was 14 percent greater than the expected prevalence based on federal health survey data of a ...
(MEMPHIS, Tenn. - May 11, 2015) Researchers have identified three genes that play a pivotal role in the brain tumor choroid plexus carcinoma (CPC), a discovery that lays the groundwork for more effective treatment of this rare, often fatal cancer. St. Jude Children's Research Hospital scientists led the study, which appears today in the journal Cancer Cell.
The genes - TAF12, NFYC and RAD54L - are involved in DNA repair and regulation. Researchers showed that CPC often has at least one extra copy of each gene and demonstrated that the genes work cooperatively to launch ...
A new study finds that men with prostate cancer that has spread to nearby lymph nodes, who have a significant risk of dying from the disease, can benefit from the addition of radiation therapy to treatments that block the effects of testosterone. The findings imply that the almost half of patients with node-positive disease nationwide who this study found had not received combination therapy were not receiving the treatment that could best control their tumor and possibly save their lives. The report from investigators at the Massachusetts General Hospital (MGH) Cancer ...
EAST LANSING, Mich. - When it comes to winning evolutionary fitness races, the tortoise once again prevails over the hare.
In the current issue of Proceedings of the National Academy of Sciences, a team of BEACON scientists centered at Michigan State University found that limiting migrations among populations of bacteria produced better adaptations.
The cost, however, was that the bacteria evolved slower. Taking your time, however, isn't always a bad thing, said Joshua Nahum, MSU biocomputational research associate.
"We name this the Tortoise-Hare pattern, as it is ...
Achieving sustainability requires a sophisticated understanding of continuously evolving resource, production, and consumption systems that make up society's relationship to nature. In a special new issue, Yale's Journal of Industrial Ecology illustrates how the field is increasingly turning to complexity science for tools and insights in its pursuit of reduced environmental impacts.
In the special issue, "Advances in Complex Adaptive Systems and Industrial Ecology," a group of international researchers show how integration of complex adaptive system into the study of ...
May 11, 2015 -- (BRONX, NY) -- A survey of more than 1,000 U.S. adults has found that misperceptions about miscarriage and its causes are widespread. Results of the survey, conducted by researchers at Albert Einstein College of Medicine of Yeshiva University and Montefiore Health System, show that feelings of guilt and shame are common after a miscarriage and that most people erroneously believe that miscarriages are rare. The findings were published online today in the journal Obstetrics & Gynecology.
Nearly one million miscarriages occur in the U.S. each year. Miscarriages ...
May 11, 2015 -- Ongoing efforts by the Centers for Disease Control and Prevention (CDC) to reduce the population impact of traumatic brain injury (TBI) are documented in the May/June issue of The Journal of Head Trauma Rehabilitation, official journal of the Brain Injury Association of America. The journal is published by Wolters Kluwer.
"This special issue draws attention to the need for strategies to prevent TBI and to lessen the substantial physical, psychological, economic, and social effects among people who experience it," write co-editors Jeneita M. Bell, MD, MPH ...
As the nation observes the May 17 anniversary of the Supreme Court decision that ended racial segregation in public schools, a new study has found that desegregated schooling is tied to better performance for certain cognitive abilities in older African American Adults.
This research is published in an article titled "Education Desegregation and Cognitive Change in African American Older Adults," appearing in the May 2015 issue of The Journals of Gerontology, Series B: Psychological Sciences and Social Sciences.
"Our findings suggest that there is a slight, but statistically ...
