Flexible, Low-Cost, Water-Repellent Gaphene Circuits

New graphene printing technology can produce electronic circuits that are low-cost, flexible, highly conductive and water repellent. The nanotechnology “would lend enormous value to self-cleaning wearable/washable electronics that are resistant to stains, or ice and biofilm formation,” according to a recent paper describing the discovery.

“We’re taking low-cost, inkjet-printed graphene and tuning it with a laser to make functional materials,” said Jonathan Claussen, an Iowa State University assistant professor of mechanical engineering, an associate of the U.S. Department of Energy’s and the corresponding author of the paper recently featured on the cover of the journal Nanoscale. The paper describes how Claussen and the nanoengineers in his research group use to create electric circuits on flexible materials. In this case, the ink is flakes of graphene – the wonder material can be a great conductor of electricity and heat, plus it’s strong, stable and biocompatible.

And now they’ve found another application of their laser processing technology: taking graphene-printed circuits that can hold water droplets (they’re hydrophilic) and turning them into circuits that repel water (they’re superhydrophobic).

We’re micro-patterning the surface of the inkjet-printed graphene,” Claussen said. “The laser aligns the graphene flakes vertically – like little pyramids stacking up. And that’s what induces the hydrophobicity.” Claussen said the energy density of the laser processing can be adjusted to tune the degree of hydrophobicity and conductivity of the printed graphene circuits. And that opens up all kinds of possibilities for new electronics and sensors, according to the paper. “One of the things we’d be interested in developing is anti-biofouling materials,” said Loreen Stromberg, a paper co-author and an Iowa State postdoctoral research associate in mechanical engineering and for the Virtual Reality Applications Center. “This could eliminate the buildup of biological materials on the surface that would inhibit the optimal performance of devices such as chemical or biological sensors.”

The technology could also have applications in flexible electronics, washable sensors in textiles, microfluidic technologies, drag reduction, de-icing, electrochemical sensors and technology that uses graphene structures and electrical simulation to produce stem cells for nerve regeneration. The researchers wrote that further studies should be done to better understand how the nano– and microsurfaces of the printed graphene creates the water-repelling capabilities. .

The Iowa State University Research Foundation is working to patent the technology and has optioned it to an Ames-based startup, NanoSpy Inc., for possible commercialization. NanoSpy, located at the Iowa State University Research Park, is developing sensors to detect salmonella and other pathogens in food processing plants. Claussen and Stromberg are part of the company.

Source: https://www.news.iastate.edu/

Glucose Monitoring Strip

A research group from the Center for Nanoparticle Research within the Institute for Basic Science (IBS) in South Korea has developed a convenient and accurate sweat-based glucose monitoring and maintenance device. The research group has furthered its previous study* (Nat. Nanotech. 11, 566, 2016) to enhance the efficiency of the sweat collection and sensing & therapy process. This sweat-based system allows rapid glucose measurement incorporating small and sensitive sensors and also comes in a disposable strip sensor to the convenience of users. This accurate glucose analysis allows to prescribe a multistep and precisely controlled dosage of drug.

sweat monitoring stripOptical camera image of the disposable sweat monitoring strip (left). The disposable sweat analysis strip on human skin with perspiration (middle).The disposable strip-type sensors connected to a zero insertion force AQ50 (ZIF) connector (right).

The previous study reported a wearable graphene-based patch that allows diabetes monitoring and feedback therapy by using human sweat. The device’s pH and temperature monitoring functions enable systematic corrections of sweat glucose measurements.

The conventional treatment protocol causes a huge stress to diabetics since it requires painful and repetitive blood-withdrawal and insulin shots. Patients become reluctant to take the periodic tests and treatments, aggravating the diabetes symptoms and suffer severe diabetic complications. A recent alternative approach, sweat-based monitoring offers a painless blood glucose monitoring method, enabling more convenient control of blood glucose levels. However, many challenges still exist for the practical application of the existing system: tedious blood collection procedure; error-prone, enzyme-based glucose sensing that may lead to overtreatment of drugs, etc.

To address such issues, the research group presented an easy-to-use and multistage module to ensure an accurate glucose monitoring and therapy. To speed up the sweat collection, the researchers redevised the system to work under a small amount of sweat. They used electrochemically active, porous metal electrodes (replacing the graphene materials of the previous study) to enhance the sensitivity of the system. Also the porous structure allows to form strong linkage among enzymes, resulting in increased reliability of the sensors under mechanical friction and deformation.

Source: http://www.ibs.re.kr/

The Glove That Gives You Super-Human Strength

The Bioservo or Soft Extra Muscles (SEM) glove mimics the human hand by using artificial tendons, motors and sensors for added muscle strength. The Swedish company is partnering with GMNASA to develop a glove to be used in manufacturing and other industrial applications.

GM-NASA Space Robot ‘Power’ Glove Finds New Life on EarthCLICK ON THE IMAGE TO ENJOY THE VIDEO

In 2012, General Motors and NASA developed a technology that could be used by both auto workers and astronauts aboard the International Space Station. Using actuators, artificial tendons, and sensors to mimic and multiply the function of the human hand, the battery-powered RoboGlove was designed to alleviate the stress and muscle fatigue of repetitive mechanical work in space. Now, according to The Verge, GM has licensed the RoboGlove to Bioservo Technologies, a Swedish medical tech company, so that it can finally be used to help workers here on Earth. Bioservo will fuse the RoboGlove technology with its own Soft Extra Muscle (SEM) Glove technology in order to make gloves for industrial use, according a press release from GM. “Combining the best of three worlds—space technology from NASA, engineering from GM and medtech from Bioservo—in a new industrial glove could lead to industrial scale use of the technology,” comments Tomas Ward, CEO of Bioservo Technologies.

Factory workers are about to get super-human strength. The glove helped scientists control Robonaut 2, a humanoid that provided engineering and technical assistance on space mission just like Star Wars’ R2-D2. But now it has been given power-boosting technologies.
Being a combination of sensors that function like human nerves, muscles and tendons the new Power Glove has the same dexterity of the human hand – but with mammoth strength. The ground-breaking muscle-mimicking technologies could help employees in health care. The glove could slash the amount of force an assembly operator needs to hold a tool during an operation in half.

Source: http://www.dailymail.co.uk/

How To Safely Use Graphene Implants Into Tissues

In the future, our health may be monitored and maintained by tiny sensors and drug dispensers, deployed within the body and made from grapheneone of the strongest, lightest materials in the world. Graphene is composed of a single sheet of carbon atoms, linked together like razor-thin chicken wire, and its properties may be tuned in countless ways, making it a versatile material for tiny, next-generation implants. But graphene is incredibly stiff, whereas biological tissue is soft. Because of this, any power applied to operate a graphene implant could precipitously heat up and fry surrounding cells.

Now, engineers from MIT and Tsinghua University in Beijing have precisely simulated how electrical power may generate heat between a single layer of graphene and a simple cell membrane. While direct contact between the two layers inevitably overheats and kills the cell, the researchers found they could prevent this effect with a very thin, in-between layer of water. By tuning the thickness of this intermediate water layer, the researchers could carefully control the amount of heat transferred between graphene and biological tissue. They also identified the critical power to apply to the graphene layer, without frying the cell membrane.

Co-author Zhao Qin, a research scientist in MIT’s Department of Civil and Environmental Engineering (CEE), says the team’s simulations may help guide the development of graphene implants and their optimal power requirements.

graphene2014

We’ve provided a lot of insight, like what’s the critical power we can accept that will not fry the cell,” Qin says. “But sometimes we might want to intentionally increase the temperature, because for some biomedical applications, we want to kill cells like cancer cells. This work can also be used as guidance [for those efforts.

Qin’s co-authors include Markus Buehler, head of CEE and the McAfee Professor of Engineering, along with Yanlei Wang and Zhiping Xu of Tsinghua University.
The results are published today in the journal Nature Communications.

Source: http://news.mit.edu/

Smart Threads For Clothing And Robots

Fabrics containing flexible electronics are appearing in many novel products, such as clothes with in-built screens and solar panels. More impressively, these fabrics can act as electronic skins that can sense their surroundings and could have applications in robotics and prosthetic medicine. King Abdullah University of Science and Technology (KAUST – Saudi Arabia) researchers have now developed smart threads that detect the strength and location of pressures exerted on them1. Most flexible sensors function by detecting changes in the electrical properties of materials in response to pressure, temperature, humidity or the presence of gases. Electronic skins are built up as arrays of several individual sensors. These arrays currently need complex wiring and data analysis, which makes them too heavy, large or expensive for large-scale production.

Yanlong Tai and Gilles Lubineau from the University’s Division of Physical Science and Engineering have found a different approach. They built their smart threads from cotton threads coated with layers of one of the miracle materials of nanotechnology: single-walled carbon nanotubes (SWCNTs).

smart threadsThe twisted smart threads developed by KAUST researchers can be woven into pressure-sensitive electronic skin fabrics for use in novel clothing, robots or medical prosthetics

Cotton threads are a classic material for fabrics, so they seemed a logical choice,” said Lubineau. “Networks of nanotubes are also known to have piezoresistive properties, meaning their electrical resistance depends on the applied pressure.”

The researchers showed their threads had decreased resistance when subjected to stronger mechanical strains, and crucially the amplitude of the resistance change also depended on the thickness of the SWCNT coating.

These findings led the researchers to their biggest breakthrough: they developed threads of graded thickness with a thick SWCNT layer at one end tapering to a thin layer at the other end. Then, by combining threads in pairs—one with graded thickness and one of uniform thickness—the researchers could not only detect the strength of an applied pressure load, but also the position of the load along the threads.

Our system is not the first technology to sense both the strength and position of applied pressures, but our graded structure avoids the need for complicated electrode wirings, heavy data recording and analysis,” said Tai.

The researchers have used their smart threads to build two- and three-dimensional arrays that accurately detect pressures similar to those that real people and robots might be exposed to.
We hope that electronic skins made from our smart threads could benefit any robot or medical prosthetic in which pressure sensing is important, such as artificial hands,” said Lubineau.

https://discovery.kaust.edu.sa/

How To Monitor and Combat Diabetes With A Simple Patch

In the future, diabetics may be able to replace finger prick tests and injections with this non-invasive smart patch to keep their glucose levels in check.

patch against diabetesCLICK ON THE IMAGE TO ENJOY THE VIDEO

The device is a type of patch which enables diabetic patients to monitor blood sugar levels via sweat without taking blood samples and control glucose levels by injecting medication“, says Kim Dae-Hyeong, researcher at the Institute for Basic Science (IBS), Seoul National University, South Korea.

After analyzing the patient’s sweat to sense glucose, the patch’s embedded sensors constantly test pH, humidity, and temperature – important factors for accurate blood sugar readings. The graphene-based patch is studded with micro-needles coated with medication that pierce the skin painlessly. When the patch senses above normal glucose levels a tiny heating element switches on which dissolves the medication coating the microneedles and releases it into the body. The prototype worked well in mice trials.

Diabetic patients can easily use our device because it does not cause any pain or stress them out. So they can monitor and manage blood glucose levels more often to prevent increasing it. Therefore, our device can greatly contribute to helping patients avoid complications of the disease“, comments Professor Kim Dae-Hyeong. Researchers want to lower the cost of production, while figuring out how to delivery enough medication to effectively treat humans, both major hurdles towards commercialization. The research was published in the journal Nature Nanotechnology in March.

Source: http://www.ibs.re.kr/

How To Detect Contaminants In One Single Molecule

A technique to combine the ultrasensitivity of surface enhanced Raman* scattering (SERS) with a slippery surface invented by Penn State researchers will make it feasible to detect single molecules of a number of chemical and biological species from gaseous, liquid or solid samples. This combination of slippery surface and laser-based spectroscopy will open new applications in analytical chemistry, molecular diagnostics, environmental monitoring and national security.

The researchers, led by Tak-Sing Wong, assistant professor of mechanical engineering, call there invention SLIPSERS, which is a combination of Wong’s slippery liquid-infused porous surfaces (SLIPS), which is a biologically inspired surface based on the Asian pitcher plant, and SERS.

Detect contaminants in one single moleculeWe have been trying to develop a sensor platform that allows us to detect chemicals or biomolecules at a single molecule level whether they are dispersed in air, liquid phase, or bound to a solid,” Wong said. “Being able to identify a single molecule is already very difficult. Being able to detect those molecules in all three phases, that is really challenging.”

Our technique opens up larger possibilities for people to use other types of solvents to do single molecule SERS detection, such as environmental detection in soil samples. If you can only use water, that is very limiting,” Yang said. “In biology, researchers might want to detect a single base pair mismatch in DNA. Our platform will give them that sensitivity.”

One of the next steps will be to detect biomarkers in blood for disease diagnosis at the very early stages of cancer when the disease is more easily treatable. “We have detected a common protein, but haven’t detected cancer yet,” Yang said.

*Raman spectroscopy is a well-known method of analyzing materials in a liquid form using a laser to interact with the vibrating molecules in the sample. The molecule’s unique vibration shifts the frequency of the photons in the laser light beam up or down in a way that is characteristic of only that type of molecule.

Source: http://www.newswise.com/

How To Move Ten Times Faster in Water

Scientists at the University College London (UCL) have identified a new and potentially faster way of moving molecules across the surfaces of certain materials.

The team carried out sophisticated computer simulations of tiny droplets of water as they interact with graphene surfaces. These simulations reveal that the molecules can “surf” across the surface whilst being carried by the moving ripples of graphene.

moving fast in water

The study, published in Nature Materials, demonstrates that because the molecules were swept along by the movement of strong ripples in the carbon fabric of graphene, they were able to move at an exceedingly fast rate, at least ten times faster than previously observed.

Furthermore, the researchers found that by altering the size of the ripples, and the type of molecules on the surface, they could achieve fast and controlled motion of molecules other than water. This opens up a range of possibilities for industrial applications such as improved sensors and filters.

graphene and water

Professor Angelos Michaelides, from the Thomas Young Centre and London Centre for Nanotechnology (LCN) at UCL, lead researcher of the study, explained: “Atoms and molecules usually move across materials by hopping from one point on their surface to the next. However, through computer simulations we have uncovered an interesting new diffusion mechanism for motion across graphene that is inherently different from the usual random movements we see on other surfaces.

Source: https://www.ucl.ac.uk/

A Phone So Smart, It Sniffs Out Cancer

Scientists have been exploring new ways to “smell” signs of cancer by analyzing what’s in patients’ breath. Funded by a grant from the European Commission, the SNIFFPHONE project will link Prof. Haick’s from Technion Israel acclaimed breathalyzer screening technology to the smartphone to provide non-invasive, fast and cheap disease detection. It will work by using micro- and nano-sensors that read exhaled breath and then transfer the information through the attached mobile phone to an information-processing system for interpretation. The data is then assessed and disease diagnosis and other details are ascertained. In ACS‘ journal Nano Letters, the team now reports new progress toward this goal. The researchers have developed a small array of flexible sensors, which accurately detect compounds in breath samples that are specific to ovarian cancer.

Nano sensor to detect cancer

Diagnosing cancer today usually involves various imaging techniques, examining tissue samples under a microscope, or testing cells for proteins or genetic material. In search of safer and less invasive ways to tell if someone has cancer, scientists have recently started analyzing breath and defining specific profiles of compounds in breath samples. But translating these exhaled disease fingerprints into a meaningful diagnosis has required a large number of sensors, which makes them impractical for clinical use. Hossam Haick and colleagues sought to address this problem.

The researchers developed a small, breath-diagnostic array based on flexible gold-nanoparticle sensors for use in an “electronic nose.” The system — tested on breath samples from 43 volunteers, 17 of whom had ovarian cancer — showed an accuracy rate of 82 percent. This approach could also apply to diagnostics for other diseases.

Source: http://www.technion.ac.il/
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http://pubs.acs.org/

Graphene Nanoribbons Boost Electronics

Graphene, an atom-thick material with extraordinary properties, is a promising candidate for the next generation of dramatically faster, more energy-efficient electronics. However, scientists have struggled to fabricate the material into ultra-narrow strips, called nanoribbons, that could enable the use of graphene in high-performance semiconductor electronics.

Now, University of Wisconsin-Madison engineers have discovered a way to grow graphene nanoribbons with desirable semiconducting properties directly on a conventional germanium semiconductor wafer. This advance could allow manufacturers to easily use graphene nanoribbons in hybrid integrated circuits, which promise to significantly boost the performance of next-generation electronic devices. The technology could also have specific uses in industrial and military applications, such as sensors that detect specific chemical and biological species and photonic devices that manipulate light.

In a paper published Aug. 10 in the journal Nature Communications, Michael Arnold, an associate professor of materials science and engineering at UW-Madison, Ph.D. student Robert Jacobberger, and their collaborators describe their new approach to producing graphene nanoribbons. Importantly, their technique can easily be scaled for mass production and is compatible with the prevailing infrastructure used in semiconductor processing.

graphene nanoribbonsProgressively zoomed-in images of graphene nanoribbons grown on germanium. The ribbons automatically align perpendicularly and naturally grow in what is known as the armchair edge configuration.

 

 

Graphene nanoribbons that can be grown directly on the surface of a semiconductor like germanium are more compatible with planar processing that’s used in the semiconductor industry, and so there would be less of a barrier to integrating these really excellent materials into electronics in the future,” Arnold says.

Source: http://news.wisc.edu/

Thoughs Control Bionic Leg

Gummi Olafsson doesn’t have to think about how his foot moves. That’s despite sporting a bionic prosthethic leg. He felt the new sense of control over his bionic limb almost instantly.  “As soon as I put my foot on, it took me about 10 minutes to get control of it. I could stand up and just walk away.” It’s all thanks to tiny sensors in his remaining leg muscle picking up the brain’s signals to nerve-endings and linked to a receiver in his prosthesis.

bionic legCLICK ON THE IMAGE TO ENJOY THE VIDEO

We put sensors into the muscles, and the muscles would pick up the signals, and the signals move their way into the prosthetics, and then the prosthetics react as your brain wants,” says Thorvaldur Ingvarsson,  Director of Research and orthopaedic surgeon,  from the company Ossur (Iceland).
Ossur, a prosthetics specialist, uses implanted myoelectric sensors developed in the United States combined with its own bionic limbs.

The Icelandic company says it’s the first time amputees have ever been able to control lower-limb prostheses subconsciously. Patients will soon be able to ‘upgrade‘ existing prosthetics and control them using their minds. In the future, the sensors could be developed to react to the environment.
Our ultimate goal is to replace the function of the lost limb. The next step might be to get sensing from the environment so you have a feedback loop,” adds Ingvarsson.

For now, Gummi’s body is still adapting to the responsive prosthetic.  Gummi comments: “Everyday if you are using it, you’re always getting more and more control over what you’re doing with your foot, so in a way, everyday you’re learning more about how to walk properly with the foot, how to use it to go downhill, uphill, downstairs, upstairs, even sitting down and standing up from a chair.
The company plans to extend trials of their mind-controlled bionic limb beyond Gummi and a second patient. They say it brings amputees a step closer to truly integrating their prostheses with their bodies.

Source: http://www.reuters.com/
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http://www.ossur.com/

Bionic Arm At Low Price

Stella Azambullo lost her right arm in an industrial accident. Now after years of limited dexterity, she’s testing this low-cost bionic arm which helps her perform everyday tasks.

bionic arm 2The flexible claw-like hand has a thumb, index and middle finger. Covered in a skin-like glove, it looks indistinguishable from Stella’s real arm. Sensors in the bionic limb detect electric signals from moving muscles. The signal is relayed to a motor that opens and closes the hand. Project engineer Luciana Joliat teaches patients like Stella how to use the device

I work directly with the patient and the stump to look for the strongest myoelectric signals before voluntary contractions. I train the patient to activate two muscle groups to activate the opening and closing sensors, to direct the prosthetic and make open and close, says Luciana Joliat, bioengineer in charge of the patient. Stella can now perform tasks that were impossible with her clunkier mechanical prostheses.
I’m doing very well. I’m happy to be able to do lots of things again, mainly things around the house, and also I’m happy aesthetically. Being able to go back to work has really helped me. I feel good and can move forward and start doing what I used to do“, comments Stella.
Developers from the company Bioparx Health Technology (Argentina) underscore that it is Latin America’s first budget bionic arm with sensors that respond to nerve impulses. Bioparx director and enginneer, Ricardo Rodriguez says the device is more affordable than others on the market.”We’ve achieved a cost around 50 percent less compared to similar models that we’re competing with“.

Source: http://www.bioparx.com/
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http://www.reuters.com/