Thousands of liquid crystal data points give portable device its accuracy
A new wearable medical device can quickly alert a person if they are having cardiovascular trouble or if it's simply time to put on some skin moisturizer, reports a Northwestern University and University of Illinois at Urbana-Champaign study.
The small device, approximately five centimeters square, can be placed directly on the skin and worn 24/7 for around-the-clock health monitoring. The wireless technology uses thousands of tiny liquid crystals on a flexible substrate to sense heat. When the device turns color, the wearer knows something is awry.
"Our device is mechanically invisible -- it is ultrathin and comfortable -- much like skin itself," said Northwestern's Yonggang Huang, one of the senior researchers. The research team tested the device on people's wrists.
"One can imagine cosmetics companies being interested in the ability to measure skin's dryness in a portable and non-intrusive way," Huang said. "This is the first device of its kind."
Huang led the portion of the research focused on theory, design and modeling. He is the Joseph Cummings Professor of Civil and Environmental Engineering and Mechanical Engineering at Northwestern's McCormick School of Engineering and Applied Science.
The technology and its relevance to basic medicine have been demonstrated in this study, although additional testing is needed before the device can be put to use. Details are reported online in the journal Nature Communications.
"The device is very practical -- when your skin is stretched, compressed or twisted, the device stretches, compresses or twists right along with it," said Yihui Zhang, co-first author of the study and research assistant professor of civil and environmental engineering at Northwestern.
The technology uses the transient temperature change at the skin's surface to determine blood flow rate, which is of direct relevance to cardiovascular health, and skin hydration levels. (When skin is dehydrated, the thermal conductivity property changes.)
The device is an array of up to 3,600 liquid crystals, each half a millimeter square, laid out on a thin, soft and stretchable substrate.
When a crystal senses temperature, it changes color, Huang said, and the dense array provides a snapshot of how the temperature is distributed across the area of the device. An algorithm translates the temperature data into an accurate health report, all in less than 30 seconds.
"These results provide the first examples of 'epidermal' photonic sensors," said John A. Rogers, the paper's corresponding author and a Swanlund Chair and professor of materials science and engineering at the University of Illinois. "This technology significantly expands the range of functionality in skin-mounted devices beyond that possible with electronics alone."
Rogers, who also is director of the Seitz Materials Research Laboratory, led the group that worked on the experimental and fabrication work of the device. He is a longtime collaborator of Huang's.
With its 3,600 liquid crystals, the photonic device has 3,600 temperature points, providing sub-millimeter spatial resolution that is comparable to the infrared technology currently used in hospitals.
The infrared technology, however, is expensive and limited to clinical and laboratory settings, while the new device offers low cost and portability.
The device also has a wireless heating system that can be powered by electromagnetic waves present in the air. The heating system is used to determine the thermal properties of the skin.
The title of the paper is "Epidermal Photonic Devices for Quantitative Imaging of Temperature and Thermal Transport Characteristics of the Skin." In addition to Zhang, Li Gao and Viktor Malyarchuk of the University of Illinois at Urbana-Champaign are co-first authors.
Megan Fellman | Eurek Alert!
UCLA engineers use deep learning to reconstruct holograms and improve optical microscopy
22.11.2017 | University of California - Los Angeles
First transcatheter implant for diastolic heart failure successful
16.11.2017 | The Ohio State University Wexner Medical Center
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
23.11.2017 | Life Sciences
23.11.2017 | Earth Sciences
23.11.2017 | Earth Sciences