Wearable sensors that detect gas leaks
2021-04-16
(Press-News.org) Gas accidents such as toxic gas leakage in factories, carbon monoxide leakage of boilers, or toxic gas suffocation during manhole cleaning continue to claim lives and cause injuries. Developing a sensor that can quickly detect toxic gases or biochemicals is still an important issue in public health, environmental monitoring, and military sectors. Recently, a research team at POSTECH has developed an inexpensive, ultra-compact wearable hologram sensor that immediately notifies the user of volatile gas detection.
A joint research team led by Professor Junsuk Rho of departments of mechanical and chemical engineering and Dr. Inki Kim of Department of Mechanical Engineering with Professor Young-Ki Kim and Ph.D. candidate Won-Sik Kim of Department of Chemical Engineering at POSTECH has integrated metasurface with gas-reactive liquid crystal optical modulator to develop a sensor that provides an immediate visual holographic alarm when harmful gases are detected. The findings from this study were published in Science Advances on April 7, 2021.
For those working in hazardous environments such as petrochemical plants, gas sensors are life. However, conventional gas sensing devices are not widely used due to their high cost of being made with complex machines and electronic devices. In addition, commercial gas sensors have limitations in that they are difficult to use, and have poor portability and reaction speed.
To solve these issues, the research team utilized the metasurface, well known as a future optical device known to have the invisible cloak effect through making visible objects disappear by controlling the refractive index of light. Metasurface is especially used to transmit two-way holograms or 3D video images by freely controlling light.
Using the metasurface, the research team developed a gas sensor that can float a holographic image alarm in space in just a few seconds by using the polarization control of transmitted light that transforms due to the change in orientation of liquid crystal molecules in the liquid crystal layer inside the sensor device when exposed to gas. Moreover, this gas sensor developed by the research team requires no support from external mechanical or electronic devices, unlike other conventional commercial gas sensors. The researchers used isopropyl alcohol as the target hazardous gas, known as a toxic substance that can cause stomach pain, headache, dizziness, and even leukemia.
The newly developed sensor was confirmed to detect even the minute amount of gas of about 200ppm. In an actual experiment using a board marker, a volatile gas source in our daily life, a visual holographic alarm popped up instantaneously the moment the marker was brought to the sensor.
Moreover, the research team developed a one-step nanocomposite printing method to produce this flexible and wearable gas sensor. The metasurface structure, which was previously processed on a hard substrate, was designed to enable rapid production with a single-step nanocasting process on a curved or flexible substrate.
When the flexible sensor fabricated using this method attaches like a sticker on safety glasses, it can detect gas and display a hologram alarm. It is anticipated to be integrable with glass-type AR display systems under development at Apple, Samsung, Google, and Facebook.
Going a step further, the research team is developing a high-performance environmental sensor that can display the type and concentration level of gases or biochemicals in the surroundings with a holographic alarm, and is studying optical design techniques that can encode various holographic images. If these studies are successful, they can be used to reduce accidents caused by biochemical or gas leaks.
"This newly developed ultra-compact wearable gas sensor provides a more intuitive holographic visual alarm than the conventional auditory or simple light alarms," remarked Prof. Junsuk Rho. "It is anticipated to be especially effective in more extreme work environments where acoustic and visual noise are intense."
INFORMATION:
This study was conducted with the support from the Mid-career Researcher Program, Global Frontier, Regional Leading Research Center, Future Materials Discovery, and the Sejong Science Fellowship of the National Research Foundation of the Ministry of Science and ICT of Korea.
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-04-16
A person who owns a car or who has a college education may be less vulnerable to COVID-19, according to an analysis of cases in Tehran, Iran, one of the early epicenters of the pandemic. While such variables do not inherently lower a person's risk, they do indicate an infrastructure of protection that persists despite how densely populated a person's district might be.
The international collaboration published their results on April 3 in Sustainable Cities and Society.
"In the past few decades, there have been various efforts aimed at increasing urban density to enhance efficiency and contribute to climate change mitigation -- but the COVID-19 pandemic has brought questions about ...
2021-04-16
The nervous system is the internet of the human body and can in the same way transfer signals over long distances very quickly. Some of the most important elements in this signaling are the axons. They are projections of the nerve cells which send signals to other nerve cells or muscles. For instance, axons that jut out from nerve cells in the spinal cord can be over one meter long.
Researchers from the Faculty of Health and Medical Sciences at the University of Copenhagen have now in a new study examined how signal molecules are transported in ...
2021-04-16
Scientists have called for the use of climate projections in conservation planning, to ensure that areas most at risk from biodiversity loss and climate impacts are protected. Protected areas are often created in areas of low population density and remote locations, rather than because of their biodiversity conservation potential. Conservation planning in tropical forests especially tends to be less rigorous and climate rarely taken into account, they said.
But climate projections and science-based information are critical to actively seek out and safeguard areas where species are most at risk and ecosystems are fast declining, said authors of the ...
2021-04-16
New research has shed light on how autism-spectrum disorder (ASD) manifests in the brains of girls, prompting the scientists to warn that conclusions drawn from studies conducted primarily in boys should not be assumed to hold true for girls.
The researchers discovered that there is a significant difference in the genes and "genetic burden" that underpin the condition in girls and boys. They also identified specific ways the brains of girls with ASD respond differently to social cues such as facial expressions and gestures than do those of girls without ASD.
"This new study provides us with a roadmap for understanding how to better match current and future evidenced-based interventions to underlying ...
2021-04-16
A candidate vaccine that could provide protection against the COVID-19 virus and other coronaviruses has shown promising results in early animal testing.
The candidate coronavirus vaccines, created by Virginia Tech's University Distinguished Professor X.J. Meng and UVA Health's Professor Steven L. Zeichner, prevented pigs from being becoming ill with a pig coronavirus, porcine epidemic diarrhea virus (PEDV).
The researchers have recently published their findings in the Proceedings of the National Academy of Sciences.
"The candidate vaccine was developed using an innovative vaccine platform targeting a highly conserved genomic region of coronaviruses," said Meng, a University ...
2021-04-16
Angiogenesis is a process of new vessel formation that is activated both in physiological (tissue repair, reproduction, etc.) and pathological (myocardial infarction, diabetic retinopathy, cancer, etc.) conditions. The process is carried out by endothelial cells and includes their proliferation, migration and arrangement in tubes. Angiogenesis regulation is precise and is mainly mediated by pro-angiogenic factors, such as vascular endothelial growth factor (VEGF), which in turn promote different signalling pathways leading to an increase of intracellular Ca2+ concentrations.
The researchers from the Cardiovascular Pathophysiology group at the Institute ...
2021-04-16
A team of researchers, affiliated with UNIST has proposed a satellite-aided drought monitoring method that can adequately represent the complex drought conditions into a single integrated drought index. The newly-proposed drought index has attracted considerable attention as a new method for monitoring and forecasting drought hazards due to its accuracy with no space-time constraints.
Drought is one of the most complex natural disasters. Therefore, unlike most other natural disasters, it is usually difficult to define the drought onset or drought declaration. For this reason, various drought indices (i.e., drought severity, the area affected, duration, and timing) are used to monitor drought and its risk management. The existing drought indices are tended to be specific to particular ...
2021-04-16
Researchers at UniSA have developed a cost-effective technique that could deliver safe drinking water to millions of vulnerable people using cheap, sustainable materials and sunlight.
Less than 3 per cent of the world's water is fresh, and due to the pressures of climate change, pollution, and shifting population patterns, in many areas this already scarce resource is becoming scarcer.
Currently, 1.42 billion people - including 450 million children - live in areas of high, or extremely high, water vulnerability, and that figure is expected to grow in coming decades.
Researchers at UniSA's Future Industries Institute have developed a promising new process that could eliminate water stress for millions of people, including those living in many of the planet's most vulnerable ...
2021-04-16
Reston, VA--New research shows that a novel positron emission tomography (PET) tracer that targets inflammation is safe and can clearly identify early stages of rheumatoid arthritis. The promising PET tracer, 68Ga-DOTA-Siglec-9, rapidly clears from blood circulation, has a low radiation dose, and can be easily produced. This first-in-human study was published in the April issue of the Journal of Nuclear Medicine.
Inflammation is a significant part of several chronic diseases, including rheumatoid arthritis and its related issues. While PET imaging with 18F-FDG is a valuable tool for the diagnosis and monitoring of the effects of treatments, it is not specific enough to assess inflammation.
"It's important to detect inflammation early so that patients ...
2021-04-16
New UCLA research suggests that elderly patients of female physicians are more likely than those of male physicians in the same outpatient practice to be vaccinated against the flu.
This trend holds for all racial and ethnic groups studied and could provide insight into improving vaccination rates for influenza, COVID-19 and other illnesses, according to the research letter, which is published in the peer-reviewed JAMA Internal Medicine.
Prior studies have shown that female physicians tend to spend more time with their patients, said study author Dr. Dan Ly, an assistant professor in the division of general internal medicine and health services research at the David ...
LAST 30 PRESS RELEASES:
[Press-News.org] Wearable sensors that detect gas leaks
