Tag Archives: Yang Liu

Using carbon dots (organic nanosensors) to detect pesticides

Before getting to the latest about carbon dots, there’s something to be clarified (and it was news to me), a carbon dot is not a quantum dot. So says this 2020 paper, “Advances in carbon dots: from the perspective of traditional quantum dots” by Yanhong Liu, Hui Huang, Weijing Cao, Baodong Mao, Yang Liu, and Zhenhui Kang. Mater. Chem. Front., 2020,4, 1586-1613 First published March 17, 2020.


Quantum dots (QDs) have been the core concept of nanoscience and nanotechnology since their inception, and play a dominant role in the development of the nano-field. Carbon dots (CDots), defined by a feature size of <10 nm, have become a rising star in the crossover field of carbon materials and traditional QDs (TQDs). CDots possess many unique structural, physicochemical and photochemical properties that render them a promising platform for biology, devices, catalysis and other applications. …

This story is about carbon dots but you can find out more about quantum dots in my October 6, 2023 posting concerning the 2023 Nobel prizes; scroll down to the ‘Chemistry’ subhead.

An August 30, 2023 news item on phys.org describes work from Concordia University (Montréal, Canada) on carbon dots,

Researchers at Concordia have developed a new system using tiny nanosensors called carbon dots to detect the presence of the widely used chemical glyphosate. Their research, titled “Ratiometric Sensing of Glyphosate in Water Using Dual Fluorescent Carbon Dots,” is published in Sensors.

An August 30, 2023 Concordia University news release (also on EurekAlert) by Patrick Lejtenyi, which originated the news item, explains the importance of the work and provides more technical details, Note: Links have been removed,

Glyphosate is a pesticide found in more than 750 agricultural, forestry, urban and home products, including Monsanto’s popular weed-killer Roundup. It is also controversial: studies have linked its overuse to environmental pollution and cancer in humans. Its sale is banned or restricted in dozens of countries and jurisdictions, including Canada.

The researchers’ system relies on the carbon dots’ chemical interaction with glyphosate to detect its presence. Carbon dots are exceedingly small fluorescent particles, usually no more than 10 or 15 nanometres in size (a human hair is between 80,000 and 100,000 nanometres). But when they are added to water solutions, these nanomaterials emit blue and red fluorescence.

The researchers employed an analysis technique called a ratiometric self-referencing assay to determine glyphosate levels in a solution. The red fluorescence emitted by the carbon dots when exposed to varying concentrations of the chemical and different pH levels is compared with a control in which no glyphosate is present. In all the tests, the blue fluorescence remained unchanged, giving the researchers a common reference point across the different tests.

They observed that higher levels of glyphosate quenched the red fluorescence, which they accredited to the interaction of the pesticide with the carbon dots’ surface.

“Our system differs from others because we are measuring the area between two peaks—two fluorescent signatures—on the visible spectrum,” says Adryanne Clermont-Paquette, a PhD candidate in biology and the paper’s lead author. “This is the integrated area between the two curves. Ratiometric measurement allows us to ignore variables such as temperature, pH levels or other environmental factors. That allows us to just only look at the levels of glyphosate and carbon dots that are in the system.”

“By understanding the chemistry at the surface of these very small dots and by knowing their optical properties, we can use them to our advantage for many different applications,” says Rafik Naccache, an associate professor of chemistry and biochemistry and the paper’s supervising author.

Research assistants Diego-Andrés Mendoza and Amir Sadeghi, along with associate professor of biology Alisa Piekny, are co-authors.

Starting small

Naccache says the technique is designed to detect minute amounts of the pesticide. The technique they developed is sensitive enough to be able to detect the presence of pesticide at levels as low as 0.03 parts per million.

“The challenge is always in the other direction, to see how low we can go in terms of sensitivity and selectivity,” he says.

There remains much work to be done before this technology can be used widely. But as Clermont-Paquette notes, this paper represents an important beginning.

“Understanding the interaction between glyphosate and carbon dots is a first step. If we are to move this along further, and develop it into a real-life application, we have to start with the fundamentals.”

The researchers are supported by funding from the Natural Sciences and Engineering Research Council of Canada.

Here’s a link to and a citation for the paper,

Ratiometric Sensing of Glyphosate in Water Using Dual Fluorescent Carbon Dots
by Adryanne Clermont-Paquette, Diego-Andrés Mendoza, Amir Sadeghi, Alisa Piekny, and Rafik Naccache. Sensors 2023, 23(11), 5200; DOI: https://doi.org/10.3390/s23115200 Published: 30 May 2023

This paper is open access.

A nontraditional artificial synaptic device and roadmap for Chinese research into neuromorphic devices

A November 9, 2022 Science China Press press release on EurekAlert announces a new approach to developing neuromorphic (brainlike) devices,

Neuromorphic computing is an information processing model that simulates the efficiency of the human brain with multifunctionality and flexibility. Currently, artificial synaptic devices represented by memristors have been extensively used in neural morphological computing, and different types of neural networks have been developed. However, it is time-consuming and laborious to perform fixing and redeploying of weights stored by traditional artificial synaptic devices. Moreover, synaptic strength is primarily reconstructed via software programming and changing the pulse time, which can result in low efficiency and high energy consumption in neural morphology computing applications.

In a novel research article published in the Beijing-based National Science Review, Prof. Lili Wang from the Chinese Academy of Sciences and her colleagues present a novel hardware neural network based on a tunable flexible MXene energy storage (FMES) system. The system comprises flexible postsynaptic electrodes and MXene nanosheets, which are connected with the presynaptic electrodes using electrolytes. The potential changes in the ion migration process and adsorption in the supercapacitor can simulate information transmission in the synaptic gap. Additionally, the voltage of the FMES system represents the synaptic weight of the connection between two neurons.

Researchers explored the changes of paired-pulse facilitation under different resistance levels to investigate the effect of resistance on the advanced learning and memory behavior of the artificial synaptic system of FMES. The results revealed that the larger the standard deviation, the stronger the memory capacity of the system. In other words, with the continuous improvement of electrical resistance and stimulation time, the memory capacity of the artificial synaptic system of FMES is gradually improved. Therefore, the system can effectively control the accumulation and dissipation of ions by regulating the resistance value in the system without changing the external stimulus, which is expected to realize the coupling of sensing signals and storage weight.

The FMES system can be used to develop neural networks and realize various neural morphological computing tasks, making the recognition accuracy of handwritten digit sets reach 95%. Additionally, the FMES system can simulate the adaptivity of the human brain to achieve adaptive recognition of similar target data sets. Following the training process, the adaptive recognition accuracy can reach approximately 80%, and avoid the time and energy loss caused by recalculation.

“In the future, based on this research, different types of sensors can be integrated on the chip to further realize multimodal sensing computing integrated architecture.” Prof. Lili Wang stated, “The device can perform low-energy calculations, and is expected to solve the problems of high write noise, nonlinear difference, and diffusion under zero bias voltage in certain neural morphological systems.”

Here’s a link to and a citation for the paper,

Neuromorphic-computing-based adaptive learning using ion dynamics in flexible energy storage devices by Shufang Zhao, Wenhao Ran, Zheng Lou, Linlin Li, Swapnadeep Poddar, Lili Wang, Zhiyong Fan, Guozhen Shen. National Science Review, Volume 9, Issue 11, November 2022, nwac158, EOI: https://doi.org/10.1093/nsr/nwac158 Published: 13 August 2022

This paper is open access.

The future (or roadmap for) of Chinese research on neuromorphic engineering

While I was trying (unsuccessfully) to find a copy of the press release on the issuing agency’s website, I found this paper,

2022 roadmap on neuromorphic devices & applications research in China by Qing Wan, Changjin Wan, Huaqiang Wu, Yuchao Yang, Xiaohe Huang, Peng Zhou, LinChen, Tian-Yu Wang, Yi Li, Kanhao Xue, Yuhui He, Xiangshui Miao, Xi Li, Chenchen Xie, Houpeng Chen, Z. T. Song, Hong Wang, Yue Hao, Junyao Zhang, Jia Huang, Zheng Yu Ren, Li Qiang Zhu, Jianyu Du, Chen Ge, Yang Liu, Guanglong Ding, Ye Zhou, Su-Ting Han, Guosheng Wang, Xiao Yu, Bing Chen, Zhufei Chu, Lunyao Wang, Yinshui Xia, Chen Mu, Feng Lin, Chixiao Chen, Bojun Cheng, Yannan Xing, Weitao Zeng, Hong Chen, Lei Yu, Giacomo Indiveri and Ning Qiao. Neuromorphic Computing and Engineering DOI: 10.1088/2634-4386/ac7a5a *Accepted Manuscript online 20 June 2022 • © 2022 The Author(s). Published by IOP Publishing Ltd

The paper is open access.

*From the IOP’s Definitions of article versions: Accepted Manuscript is ‘the version of the article accepted for publication including all changes made as a result of the peer review process, and which may also include the addition to the article by IOP of a header, an article ID, a cover sheet and/or an ‘Accepted Manuscript’ watermark, but excluding any other editing, typesetting or other changes made by IOP and/or its licensors’.*

This is neither the published version nor the version of record.

Can you make my nose more like a camel’s?

Camel Face Close Up [downloaded from https://www.asergeev.com/php/searchph/links.php?keywords=Camel_close_up]

I love that image which I found on Alexey Sergeev’s Camel Close Up webpage on his eponymous website. It turns out the photographer is in the Department of Mathematics at Texas A&M University. Thank you Mr. Sergeev.

A January 19, 2022 news item on Nanowerk describes research inspired by a camel’s nose, Note: A link has been removed,

Camels have a renowned ability to survive on little water. They are also adept at finding something to drink in the vast desert, using noses that are exquisite moisture detectors.

In a new study in ACS [American Chemical Society] Nano (“A Camel Nose-Inspired Highly Durable Neuromorphic Humidity Sensor with Water Source Locating Capability”), researchers describe a humidity sensor inspired by the structure and properties of camels’ noses. In experiments, they found this device could reliably detect variations in humidity in settings that included industrial exhaust and the air surrounding human skin.

A January 19, 2022 ACS news release (also on EurekAlert), which originated the news item, describes the work in more detail,

Humans sometimes need to determine the presence of moisture in the air, but people aren’t quite as skilled as camels at sensing water with their noses. Instead, people must use devices to locate water in arid environments, or to identify leaks or analyze exhaust in industrial facilities. However, currently available sensors all have significant drawbacks. Some devices may be durable, for example, but have a low sensitivity to the presence of water. Meanwhile, sunlight can interfere with some highly sensitive detectors, making them difficult to use outdoors, for example. To devise a durable, intelligent sensor that can detect even low levels of airborne water molecules, Weiguo Huang, Jian Song, and their colleagues looked to camels’ noses. 

Narrow, scroll-like passages within a camel’s nose create a large surface area, which is lined with water-absorbing mucus. To mimic the high-surface-area structure within the nose, the team created a porous polymer network. On it, they placed moisture-attracting molecules called zwitterions to simulate the property of mucus to change capacitance as humidity varies. In experiments, the device was durable and could monitor fluctuations in humidity in hot industrial exhaust, find the location of a water source and sense moisture emanating from the human body. Not only did the sensor respond to changes in a person’s skin perspiration as they exercised, it detected the presence of a human finger and could even follow its path in a V or L shape. This sensitivity suggests that the device could become the basis for a touchless interface through which someone could communicate with a computer, according to the researchers. What’s more, the sensor’s electrical response to moisture can be tuned or adjusted, much like the signals sent out by human neurons — potentially allowing it to learn via artificial intelligence, they say. 

The authors acknowledge funding from the Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, the Natural Science Foundation of Fujian Province, and the National Natural Science Foundation of China.

Here’s a link to and a citation for the paper,

A Camel Nose-Inspired Highly Durable Neuromorphic Humidity Sensor with Water Source Locating Capability by Caicong Li, Jie Liu, Hailong Peng, Yuan Sui, Jian Song, Yang Liu, Wei Huang, Xiaowei Chen, Jinghui Shen, Yao Ling, Chongyu Huang, Youwei Hong, and Weiguo Huang. ACS Nano 2022, 16, 1, 1511–1522 DOI: https://doi.org/10.1021/acsnano.1c10004 Publication Date:December 15, 2021 Copyright © 2021 American Chemical Society

This paper is behind a paywall.

Nanotechnology-enabled pain relief for tooth sensitivity

A November 23, 2021 news item on phys.org announces research from Australia that may lead to pain relief for anyone with sensitive teeth,

In an Australian first, researchers from the University of Queensland have used nanotechnology to develop effective ways to manage tooth sensitivity.

Dr. Chun Xu from UQ’s [University of Queensland] School of Dentistry said the approach might provide more effective long-term pain relief for people with sensitive teeth, compared to current options.

A November 23, 2021 University of Queensland press release, which originated the news item, describes the condition leading to tooth sensitivity and how the proposed solution works (Note: Links have been removed),

“Dentin tubules are located in the dentin, one of the layers below the enamel surface of your teeth,” Dr Xu said.

“When tooth enamel has been worn down, and the dentin are exposed, eating or drinking something cold or hot can cause a sudden sharp flash of pain.

“The nanomaterials used in this preclinical study can rapidly block the exposed dentin tubules and prevent the unpleasant pain.

“Our approach acts faster and lasts longer than current treatment options.

“The materials could be developed into a paste, so people who have sensitive teeth could simply apply this paste to the tooth and massage for one to three minutes.

“The next step is clinical trials.”

Tooth sensitivity affects up to 74 per cent of the population, at times severely impacting quality of life and requiring expensive treatment.

“If clinical trials are successful people will benefit from this new method that can be used at home, without the need to go to a dentist in the near future,” Dr Xu said.

“We hope this study encourages more research using nanotechnology to address dental problems.”

The team also included researchers from UQ’s Australian Institute for Bioengineering and Nanotechnology (AIBN.

Here’s a link to and a citation for the paper,

Calcium-Doped Silica Nanoparticles Mixed with Phosphate-Doped Silica Nanoparticles for Rapid and Stable Occlusion of Dentin Tubules by Yuxue Cao, Chun Xu, Patricia P. Wright, Jingyu Liu, Yueqi Kong, Yue Wang, Xiaodan Huang, Hao Song, Jianye Fu, Fang Gao, Yang Liu, Laurence J. Walsh, and Chang Lei. ACS Appl. Nano Mater. 2021, 4, 9, 8761–8769 DOI: https://doi.org/10.1021/acsanm.1c01365 Publication Date:August 25, 2021 Copyright © 2021 American Chemical Society

This paper is behind a paywall.

Unbreakable encrypted message with key that’s shorter than the message

A Sept. 5, 2016 University of Rochester (NY state, US) news release (also on EurekAlert), makes an intriguing announcement,

Researchers at the University of Rochester have moved beyond the theoretical in demonstrating that an unbreakable encrypted message can be sent with a key that’s far shorter than the message—the first time that has ever been done.

Until now, unbreakable encrypted messages were transmitted via a system envisioned by American mathematician Claude Shannon, considered the “father of information theory.” Shannon combined his knowledge of algebra and electrical circuitry to come up with a binary system of transmitting messages that are secure, under three conditions: the key is random, used only once, and is at least as long as the message itself.

The findings by Daniel Lum, a graduate student in physics, and John Howell, a professor of physics, have been published in the journal Physical Review A.

“Daniel’s research amounts to an important step forward, not just for encryption, but for the field of quantum data locking,” said Howell.

Quantum data locking is a method of encryption advanced by Seth Lloyd, a professor of quantum information at Massachusetts Institute of Technology, that uses photons—the smallest particles associated with light—to carry a message. Quantum data locking was thought to have limitations for securely encrypting messages, but Lloyd figured out how to make additional assumptions—namely those involving the boundary between light and matter—to make it a more secure method of sending data.  While a binary system allows for only an on or off position with each bit of information, photon waves can be altered in many more ways: the angle of tilt can be changed, the wavelength can be made longer or shorter, and the size of the amplitude can be modified. Since a photon has more variables—and there are fundamental uncertainties when it comes to quantum measurements—the quantum key for encrypting and deciphering a message can be shorter that the message itself.

Lloyd’s system remained theoretical until this year, when Lum and his team developed a device—a quantum enigma machine—that would put the theory into practice. The device takes its name from the encryption machine used by Germany during World War II, which employed a coding method that the British and Polish intelligence agencies were secretly able to crack.

Let’s assume that Alice wants to send an encrypted message to Bob. She uses the machine to generate photons that travel through free space and into a spatial light modulator (SLM) that alters the properties of the individual photons (e.g. amplitude, tilt) to properly encode the message into flat but tilted wavefronts that can be focused to unique points dictated by the tilt. But the SLM does one more thing: it distorts the shapes of the photons into random patterns, such that the wavefront is no longer flat which means it no longer has a well-defined focus. Alice and Bob both know the keys which identify the implemented scrambling operations, so Bob is able to use his own SLM to flatten the wavefront, re-focus the photons, and translate the altered properties into the distinct elements of the message.

Along with modifying the shape of the photons, Lum and the team made use of the uncertainty principle, which states that the more we know about one property of a particle, the less we know about another of its properties. Because of that, the researchers were able to securely lock in six bits of classical information using only one bit of an encryption key—an operation called data locking.

“While our device is not 100 percent secure, due to photon loss,” said Lum, “it does show that data locking in message encryption is far more than a theory.”

The ultimate goal of the quantum enigma machine is to prevent a third party—for example, someone named Eve—from intercepting and deciphering the message. A crucial principle of quantum theory is that the mere act of measuring a quantum system changes the system. As a result, Eve has only one shot at obtaining and translating the encrypted message—something that is virtually impossible, given the nearly limitless number of patterns that exist for each photon.

The paper by Lum and Howell was one of two papers published simultaneously on the same topic. The other paper, “Quantum data locking,” was from a team led by Chinese physicist Jian-Wei Pan.

“It’s highly unlikely that our free-space implementation will be useful through atmospheric conditions,” said Lum. “Instead, we have identified the use of optic fiber as a more practical route for data locking, a path Pan’s group actually started with. Regardless, the field is still in its infancy with a great deal more research needed.”

Here’s a link to and a citation for the paper,

Quantum enigma machine: Experimentally demonstrating quantum data locking by Daniel J. Lum, John C. Howell, M. S. Allman, Thomas Gerrits, Varun B. Verma, Sae Woo Nam, Cosmo Lupo, and Seth Lloyd. Phys. Rev. A, Vol. 94, Iss. 2 — August 2016 DOI: http://dx.doi.org/10.1103/PhysRevA.94.022315

©2016 American Physical Society

This paper is behind a paywall.

There is an earlier open access version of the paper by the Chinese researchers on arXiv.org,

Experimental quantum data locking by Yang Liu, Zhu Cao, Cheng Wu, Daiji Fukuda, Lixing You, Jiaqiang Zhong, Takayuki Numata, Sijing Chen, Weijun Zhang, Sheng-Cai Shi, Chao-Yang Lu, Zhen Wang, Xiongfeng Ma, Jingyun Fan, Qiang Zhang, Jian-Wei Pan. arXiv.org > quant-ph > arXiv:1605.04030

The Chinese team’s later version of the paper is available here,

Experimental quantum data locking by Yang Liu, Zhu Cao, Cheng Wu, Daiji Fukuda, Lixing You, Jiaqiang Zhong, Takayuki Numata, Sijing Chen, Weijun Zhang, Sheng-Cai Shi, Chao-Yang Lu, Zhen Wang, Xiongfeng Ma, Jingyun Fan, Qiang Zhang, and Jian-Wei Pan. Phys. Rev. A, Vol. 94, Iss. 2 — August 2016 DOI: http://dx.doi.org/10.1103/PhysRevA.94.020301

©2016 American Physical Society

This version is behind a paywall.

Getting back to the folks at the University of Rochester, they have provided this image to illustrate their work,

The quantum enigma machine developed by researchers at the University of Rochester, MIT, and the National Institute of Standards and Technology. (Image by Daniel Lum/University of Rochester)

The quantum enigma machine developed by researchers at the University of Rochester, MIT, and the National Institute of Standards and Technology. (Image by Daniel Lum/University of Rochester)

An easier, cheaper way to diagnose Ebola

A Sept. 9, 2015 news item on Nanotechnology Now highlights a new technology for diagnosing the Ebola virus,

A new Ebola test that uses magnetic nanoparticles could help curb the spread of the disease in western Africa. Research published in Biosensors and Bioelectronics shows that the new test is 100 times more sensitive than the current test, and easier to use. Because of this, the new test makes it easier and cheaper to diagnose cases, enabling healthcare workers to isolate patients and prevent the spread of Ebola.

The authors of the study, from the Chinese Academy of Sciences, say their new technology could be applied to the detection of any biological molecules, making it useful to diagnose other infectious diseases, like flu, and potentially detect tumors and even contamination in wastewater.

A Sept. 9, 2015 Elsevier press release, which originated the news item, provides more detail,

The Ebola virus causes an acute illness that is deadly in half of all cases, on average. The current outbreak of Ebola, which started in March 2014, affects countries in west Africa. In the most severely affected countries, like Guinea, Liberia and Sierra Leone, resources are limited, making control of the outbreak challenging. There is no vaccine for Ebola, so detecting the virus is key to controlling the outbreak: with an accurate diagnosis, patients can be isolated and treated properly, reducing the risk of spread.

“In west Africa, resources are under pressure, so complicated, expensive tests are not very helpful,” said Professor Xiyun Yan, one of the authors of the study from the Chinese Academy of Sciences. “Our new strip test is a simple, one-step test that is cheap and easy to use, and provides a visible signal, which means people don’t need training to use it. We think it will be especially helpful in rural areas, where technical equipment and skills are not available.”

Currently there are two ways to test for the Ebola virus: using a method called polymerase chain reaction (PCR), which makes copies of the molecules for detection, and with antibody-capture enzyme-linked immunosorbent assay (ELISA), which gives a visual indication when a given molecule is in a sample. PCR is very sensitive, but is expensive and complicated, requiring special skills and technical equipment. The ELISA – or gold strip test – is cheaper but sensitivity is very low, which means it often gives the wrong results.

The new test, called the nanozyme test, uses magnetic nanoparticles, which work like enzymes to make the signal stronger, giving a clearer result you can see with the naked eye. The test can detect much smaller amounts of the virus, and is 100 times more sensitive than the gold strip test.

“People have loved the strip test for many years, but it has a major weakness: it’s not sensitive enough. We’re very excited about our new nanozyme test, as it is much more sensitive and you don’t need any specialist equipment to get a quick, accurate result,” said Dr. Yan.

Strip tests work by attaching molecules called antibodies to gold particles to look for a particular molecule in a sample. When they attach to the molecule you’re looking for, in this case a virus, they produce a signal, such as a color change. In order to find the virus, the particles need to be labelled with enzymes, which speed up detection and signalling.

With the new nanozyme test, the researchers applied magnetic nanoparticles as a nanozyme probe in place of gold nanoparticles. After labeling with an antibody that attaches to the Ebola virus, this novel probe is able to recognize and separate the virus in a sample. The nanoparticles are magnetic, so to concentrate the virus particles in a sample, all you need to do is hold the sample against a magnet; no expensive equipment is needed.

The nanozyme test is 100 times more sensitive than the gold strip test, detecting molecules called glycoproteins on the surface of the Ebola virus at concentrations as low as 1 nanogram per milliliter.

The researchers have applied for a patent for the new test, which is currently being taken to west Africa by the CDC to use in the field. The researchers are also collaborating with clinical teams to apply the technology to other diseases, and with a company that treats wastewater to see if it can help remove environmental contamination.

Here’s a link to and a citation for the paper,

Nanozyme-strip for rapid local diagnosis of Ebola by Demin Duan, Kelong Fan, Dexi Zhang, Shuguang Tan, Mifang Liang, Yang Liu, Jianlin Zhang, Panhe Zhang, Wei Liu, Xiangguo Qiu, Gary P. Kobinger, George Fu Gao, Xiyun Yan. Biosensors and Bioelectronics Volume 74, 15 December 2015, Pages 134–141 doi:10.1016/j.bios.2015.05.025

This paper appears to be open access.

Monitoring health with graphene rubber bands

An Aug. 20, 2014 news item on Azonano highlights graphene research from the University of Surrey (UK) and Trinity College Dublin (Ireland),

Although body motion sensors already exist in different forms, they have not been widely used due to their complexity and cost of production.

Now researchers from the University of Surrey and Trinity College Dublin have for the first time treated common elastic bands with graphene, to create a flexible sensor that is sensitive enough for medical use and can be made cheaply.

An Aug. 15, 2014 University of Surrey press release (also on EurekAlert), which originated the news item, describes the innovation (Note: A link has been removed),

Once treated, the rubber bands remain highly pliable. By fusing this material with graphene – which imparts an electromechanical response on movement – the material can be used as a sensor to measure a patient’s breathing, heart rate or movement, alerting doctors to any irregularities.

“Until now, no such sensor has been produced that meets these needs,” said Surrey’s Dr Alan Dalton. “It sounds like a simple concept, but our graphene-infused rubber bands could really help to revolutionise remote healthcare – and they’re very cheap to manufacture.”

“These sensors are extraordinarily cheap compared to existing technologies. Each device would probably cost pennies instead of pounds, making it ideal technology for use in developing countries where there are not enough medically trained staff to effectively monitor and treat patients quickly.” [commented corresponding author, Professor Jonathan Coleman from Trinity College, Dublin]

Trinity College Dublin issued an Aug. 20, 2014 press release, which provides a little more technical detail and clarifies who led the team for anyone who may been curious about the matter,

The team – led by Professor of Chemical Physics at Trinity, Jonathan Coleman, one of the world’s leading nanoscientists – infused rubber bands with graphene, a nano-material derived from pencil lead which is 10,000 times smaller than the width of a human hair. This process is simple and compatible with normal manufacturing techniques. While rubber does not normally conduct electricity, the addition of graphene made the rubber bands electrically conductive without degrading the mechanical properties of the rubber. Tests showed that any electrical current flowing through the graphene-infused rubber bands was very strongly affected if the band was stretched. As a result, if the band is attached to clothing, the tiniest movements such as breath and pulse can be sensed.

The discovery opens up a host of possibilities for the development of wearable sensors from rubber, which could be used to monitor blood pressure, joint movement and respiration. Other applications of rubber-graphene sensors could be in the automotive industry (to develop sensitive airbags); in robotics, in medical device development (to monitor bodily motion), as early warning systems for cot death in babies or sleep apnoea in adults. They could also be woven into clothing to monitor athletes’ movement or for patients undergoing physical rehabilitation.

Professor Coleman said: “Sensors are becoming extremely important in medicine, wellness and exercise, medical device manufacturing, car manufacturing and robotics, among other areas. Biosensors, which are worn on or implanted into the skin, must be made of durable, flexible and stretchable materials that respond to the motion of the wearer. By implanting graphene into rubber, a flexible natural material, we are able to completely change its properties to make it electrically conductive, to develop a completely new type of sensor. Because rubber is available widely and cheaply, this unique discovery will open up major possibilities in sensor manufacturing worldwide.”

Here’s a link to and a citation for the paper,

Sensitive, High-Strain, High-Rate Bodily Motion Sensors Based on Graphene–Rubber Composites by Conor S. Boland, Umar Khan, Claudia Backes, Arlene O’Neill, Joe McCauley, Shane Duane, Ravi Shanker, Yang Liu, Izabela Jurewicz, Alan B. Dalton, and Jonathan N. Coleman. ACS Nano, Article ASAP DOI: 10.1021/nn503454h Publication Date (Web): August 6, 2014

Copyright © 2014 American Chemical Society

This paper is open access (I was able to open the HTML version this morning, Aug. 20, 2014). As well the researchers have made this image illustrating their work available,

[downloaded from http://pubs.acs.org/doi/full/10.1021/nn503454h]

[downloaded from http://pubs.acs.org/doi/full/10.1021/nn503454h]