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News Article
Site: http://www.rdmag.com/rss-feeds/all/rss.xml/all

Damage developing in a material can be difficult to see until something breaks or fails. A new polymer damage indication system automatically highlights areas that are cracked, scratched or stressed, allowing engineers to address problem areas before they become more problematic. The early warning system would be particularly useful in applications like petroleum pipelines, air and space transport, and automobiles - applications where one part's failure could have costly ramifications that are difficult to repair. Led by U. of I. materials science and engineering professor Nancy Sottos and aerospace engineering professor Scott White, the researchers published their work in the journal Advanced Materials. "Polymers are susceptible to damage in the form of small cracks that are often difficult to detect. Even at small scales, crack damage can significantly compromise the integrity and functionality of polymer materials," Sottos said. "We developed a very simple but elegant material to autonomously indicate mechanical damage." The researchers embedded tiny microcapsules of a pH-sensitive dye in an epoxy resin. If the polymer forms cracks or suffers a scratch, stress or fracture, the capsules break open. The dye reacts with the epoxy, causing a dramatic color change from light yellow to a bright red - no additional chemicals or activators required. The deeper the scratch or crack, the more microcapsules are broken, and the more intense the color. This helps to assess the extent of the damage. Even so, tiny microscopic cracks of only 10 micrometers are enough to cause a color change, letting the user know that the material has lost some of its structural integrity. ""Detecting damage before significant corrosion or other problems can occur provides increased safety and reliability for coated structures and composites," White said. White and Sottos are affiliated with the Beckman Institute for Advanced Science and Technology at the U. of I. The researchers demonstrated that the damage indication system worked well for a variety of polymer materials that can be applied to coat different substrates including metals, polymers and glasses. They also found that the system has long-term stability - no microcapsule leaking to produce false positives, and no color fading. In addition to averting unforeseen and costly failure, another economic advantage of the microcapsule system is the low cost, Sottos said. "A polymer needs only to be 5 percent microcapsules to exhibit excellent damage indication ability," Sottos said. "It is cost effective to acquire this self-reporting ability." Now, the researchers are exploring further applications for the indicator system, such as applying it to fiber-reinforced composites, as well as integrating it with the group's previous work in self-healing systems. "We envision this self-reporting ability can be seamlessly combined with other functions such as self-healing and corrosion protection to both report and repair damage," Sottos said. "Work is in progress to combine the ability to detect new damage with self-healing functionality and a secondary indication that reveals that crack healing has occurred."


News Article
Site: http://www.biosciencetechnology.com/rss-feeds/all/rss.xml/all

The human brain needs a large amount of energy to function properly, and researchers at the University of Illinois have reported in a new study that the health of brain metabolism in young adults may predict fluid intelligence – the capacity to solve unusual logic-based problems in novel situations. Study author Ryan Larsen, a research scientist at the Beckman Institute for Advanced Science and Technology, told Bioscience Technology that using magnetic resonance spectroscopy measurements are one of several ways to better understand the complicated relationships between energy production and intelligence. The findings were published online in Cerebral Cortex. For the study, the team, led by Larsen, University of Illinois Ph.D. candidate Aki Nikolaidis, and Beckman Institute director Arthur Kramer, analyzed data from 71 young adults.  The researchers measured the amount of N—acetyl aspartate (NAA), a biochemical marker of neural energy production and efficiency, in the brains using MR spectroscopy.   The subjects in the study were given computerized standard tests of fluid intelligence that required problem solving, reasoning and spatial visualization, Larsen said. The scientists then looked at the relationship between NAA concentrations in different areas of the brain and the results of the fluid intelligence scores. According to Larsen, the connection between NAA concentration and multiple facets of intelligence has been shown previously, but most of those studies did not use spectroscopic imaging and therefore were limited in the spatial coverage of the brain. “Our approach used spectroscopic imaging techniques to cover several areas of the brain known to be important for intelligence,” Larsen said. The current study also wanted to address other inconsistencies in previous research that may not have accounted for all relevant factors, such as brain size, in their analysis of cognition.  This study was able to image the brain’s capacity to produce energy and showed concentrations of NAA in the brain in a more detailed way than previous studies. The team found that distribution of NAA in the frontal and parietal lobes, an area of the brain associated with motor abilities, was specifically linked to fluid intelligence, independent of brain size. Interestingly, it was not linked to other closely related cognitive abilities. Brain metabolism and health, along with brain size, are significant predictors of fluid intelligence, the researchers concluded. According to the researchers, the findings suggest “that the left motor regions play a key role in visualization and planning” that is needed for spatial cognition and reasoning. So while overall, brain size is not changeable, Larsen said he is interested in understanding the potential relationships between NAA levels and health interventions, such as aerobic fitness and nutrition, which are things that can be improved and changed. Larsen said that while literature indicates that NAA is relatively stable over much of the adult lifespan, making it a useful marker of brain health, more research needs to be conducted as to whether or not changes in NAA may occur with lifestyle changes. Establish your company as a technology leader! For more than 50 years, the R&D 100 Awards have showcased new products of technological significance. You can join this exclusive community! Learn more.


News Article
Site: http://www.cemag.us/rss-feeds/all/rss.xml/all

A new class of small, thin electronic sensors can monitor temperature and pressure within the skull — crucial health parameters after a brain injury or surgery — then melt away when they are no longer needed, eliminating the need for additional surgery to remove the monitors and reducing the risk of infection and hemorrhage. Similar sensors can be adapted for postoperative monitoring in other body systems as well, the researchers say. Led by John A. Rogers, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign, and Wilson Ray, a professor of neurological surgery at the Washington University School of Medicine in St. Louis, the researchers published their work in the journal Nature. “This is a new class of electronic biomedical implants,” says Rogers, who directs the Frederick Seitz Materials Research Laboratory at Illinois. “These kinds of systems have potential across a range of clinical practices, where therapeutic or monitoring devices are implanted or ingested, perform a sophisticated function, and then resorb harmlessly into the body after their function is no longer necessary.” After a traumatic brain injury or brain surgery, it is crucial to monitor the patient for swelling and pressure on the brain. Current monitoring technology is bulky and invasive, Rogers says, and the wires restrict the patent’s movement and hamper physical therapy as they recover. Because they require continuous, hard-wired access into the head, such implants also carry the risk of allergic reactions, infection and hemorrhage, and even could exacerbate the inflammation they are meant to monitor. “If you simply could throw out all the conventional hardware and replace it with very tiny, fully implantable sensors capable of the same function, constructed out of bioresorbable materials in a way that also eliminates or greatly miniaturizes the wires, then you could remove a lot of the risk and achieve better patient outcomes,” Rogers says. ”We were able to demonstrate all of these key features in animal models, with a measurement precision that’s just as good as that of conventional devices.” The new devices incorporate dissolvable silicon technology developed by Rogers’ group at the U. of I. The sensors, smaller than a grain of rice, are built on extremely thin sheets of silicon — which are naturally biodegradable — that are configured to function normally for a few weeks, then dissolve away, completely and harmlessly, in the body’s own fluids. Rogers’ group teamed with Illinois materials science and engineering professor Paul V. Braun to make the silicon platforms sensitive to clinically relevant pressure levels in the intracranial fluid surrounding the brain. They also added a tiny temperature sensor and connected it to a wireless transmitter roughly the size of a postage stamp, implanted under the skin but on top of the skull. The Illinois group worked with clinical experts in traumatic brain injury at Washington University to implant the sensors in rats, testing for performance and biocompatibility. They found that the temperature and pressure readings from the dissolvable sensors matched conventional monitoring devices for accuracy. “The ultimate strategy is to have a device that you can place in the brain — or in other organs in the body — that is entirely implanted, intimately connected with the organ you want to monitor and can transmit signals wirelessly to provide information on the health of that organ, allowing doctors to intervene if necessary to prevent bigger problems,” says Rory Murphy, a neurosurgeon at Washington University and co-author of the paper. “After the critical period that you actually want to monitor, it will dissolve away and disappear.” The researchers are moving toward human trials for this technology, as well as extending its functionality for other biomedical applications. “We have established a range of device variations, materials and measurement capabilities for sensing in other clinical contexts,” Rogers says. “In the near future, we believe that it will be possible to embed therapeutic function, such as electrical stimulation or drug delivery, into the same systems while retaining the essential bioresorbable character.” The National Institutes of Health, the Defense Advanced Research Projects Agency, and the Howard Hughes Medical Institute supported this work. Rogers and Braun are affiliated with the Beckman Institute for Advanced Science and Technology at the U. of I. Release Date: January 18, 2016 Source: University of Illinois


The early warning system would be particularly useful in applications like petroleum pipelines, air and space transport, and automobiles - applications where one part's failure could have costly ramifications that are difficult to repair. Led by U. of I. materials science and engineering professor Nancy Sottos and aerospace engineering professor Scott White, the researchers published their work in the journal Advanced Materials. "Polymers are susceptible to damage in the form of small cracks that are often difficult to detect. Even at small scales, crack damage can significantly compromise the integrity and functionality of polymer materials," Sottos said. "We developed a very simple but elegant material to autonomously indicate mechanical damage." The researchers embedded tiny microcapsules of a pH-sensitive dye in an epoxy resin. If the polymer forms cracks or suffers a scratch, stress or fracture, the capsules break open. The dye reacts with the epoxy, causing a dramatic color change from light yellow to a bright red - no additional chemicals or activators required. The deeper the scratch or crack, the more microcapsules are broken, and the more intense the color. This helps to assess the extent of the damage. Even so, tiny microscopic cracks of only 10 micrometers are enough to cause a color change, letting the user know that the material has lost some of its structural integrity. ""Detecting damage before significant corrosion or other problems can occur provides increased safety and reliability for coated structures and composites," White said. White and Sottos are affiliated with the Beckman Institute for Advanced Science and Technology at the U. of I. The researchers demonstrated that the damage indication system worked well for a variety of polymer materials that can be applied to coat different substrates including metals, polymers and glasses. They also found that the system has long-term stability - no microcapsule leaking to produce false positives, and no color fading. In addition to averting unforeseen and costly failure, another economic advantage of the microcapsule system is the low cost, Sottos said. "A polymer needs only to be 5 percent microcapsules to exhibit excellent damage indication ability," Sottos said. "It is cost effective to acquire this self-reporting ability." Now, the researchers are exploring further applications for the indicator system, such as applying it to fiber-reinforced composites, as well as integrating it with the group's previous work in self-healing systems. "We envision this self-reporting ability can be seamlessly combined with other functions such as self-healing and corrosion protection to both report and repair damage," Sottos said. "Work is in progress to combine the ability to detect new damage with self-healing functionality and a secondary indication that reveals that crack healing has occurred." Explore further: New recipe for self-healing plastic includes dash of food additive


News Article
Site: http://www.rdmag.com/rss-feeds/all/rss.xml/all

Damage developing in a material can be difficult to see until something breaks or fails. A new polymer damage indication system automatically highlights areas that are cracked, scratched or stressed, allowing engineers to address problem areas before they become more problematic. The early warning system would be particularly useful in applications like petroleum pipelines, air and space transport, and automobiles - applications where one part's failure could have costly ramifications that are difficult to repair. Led by U. of I. materials science and engineering professor Nancy Sottos and aerospace engineering professor Scott White, the researchers published their work in the journal Advanced Materials. "Polymers are susceptible to damage in the form of small cracks that are often difficult to detect. Even at small scales, crack damage can significantly compromise the integrity and functionality of polymer materials," Sottos said. "We developed a very simple but elegant material to autonomously indicate mechanical damage." The researchers embedded tiny microcapsules of a pH-sensitive dye in an epoxy resin. If the polymer forms cracks or suffers a scratch, stress or fracture, the capsules break open. The dye reacts with the epoxy, causing a dramatic color change from light yellow to a bright red - no additional chemicals or activators required. The deeper the scratch or crack, the more microcapsules are broken, and the more intense the color. This helps to assess the extent of the damage. Even so, tiny microscopic cracks of only 10 micrometers are enough to cause a color change, letting the user know that the material has lost some of its structural integrity. ""Detecting damage before significant corrosion or other problems can occur provides increased safety and reliability for coated structures and composites," White said. White and Sottos are affiliated with the Beckman Institute for Advanced Science and Technology at the U. of I. The researchers demonstrated that the damage indication system worked well for a variety of polymer materials that can be applied to coat different substrates including metals, polymers and glasses. They also found that the system has long-term stability - no microcapsule leaking to produce false positives, and no color fading. In addition to averting unforeseen and costly failure, another economic advantage of the microcapsule system is the low cost, Sottos said. "A polymer needs only to be 5 percent microcapsules to exhibit excellent damage indication ability," Sottos said. "It is cost effective to acquire this self-reporting ability." Now, the researchers are exploring further applications for the indicator system, such as applying it to fiber-reinforced composites, as well as integrating it with the group's previous work in self-healing systems. "We envision this self-reporting ability can be seamlessly combined with other functions such as self-healing and corrosion protection to both report and repair damage," Sottos said. "Work is in progress to combine the ability to detect new damage with self-healing functionality and a secondary indication that reveals that crack healing has occurred."

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