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Dynamic inventory of graphene sensors at home and abroad
[ Instrument Network Instrument R & D ] "Graphene", also known as "single-layer graphite sheet", refers to a dense layer of carbon atoms wrapped around a honeycomb crystal lattice. The carbon atoms are arranged in a two-dimensional structure, and the single atoms of graphite Layers are similar. Graphene is widely used in sensors due to its unique two-dimensional structure. It has the characteristics of small size, large surface area, high sensitivity, fast response time, fast electron transfer, easy to fix proteins and maintain its activity, etc. Item performance.
Graphene-based nanostructures have great prospects in the field of sensors. With the development of graphene materials, the development of sensors has become even more powerful. The birth of many excellent sensors has also made production and life more intelligent and controllable.
United States
Scientists at Rutgers University New Brunswick have designed a graphene-based sensor that can detect the onset of asthma early, improve the treatment of asthma and other respiratory diseases, and prevent patients from worsening and dying.
The Defense Advanced Research Projects Agency (DARPA) -funded Reliable Neural Interface Technology (RE-NET) project enables researchers to use both optical and electronic methods to monitor and stimulate the nervous system.
NASA has developed atom-sized miniature sensors based on graphene to detect trace elements in the Earth's upper atmosphere and structural defects on spacecraft.
China
The research team led by Dr. Xu Shicai, Professor Wang Jihua, and Professor Zhou Yaoqi of Shandong Provincial Key Laboratory of Biophysics at Dezhou University made great progress in the research and development of graphene biosensing technology. The team used single crystal graphene as a sensitive material and biosensing The organic combination of technologies has successfully developed a single crystal graphene ultra-trace biosensor, which provides a new analysis method for the field of analysis and detection. The single-crystal graphene ultra-trace biosensor technology is a major world-wide research achievement obtained by Dezhou City, and has completely independent intellectual property rights.
The research result was titled "Multichannel Graphene Biosensor for Real-time and Reliable Detection of DNA Hybridization Kinetics and Affinity" and was published online in the journal Nature. "Nature · Communication" is one of the four comprehensive academic journals in the world. Its report content has a high level of scientific and technological achievements. The reviewers of the journal highly commented on this achievement: "The team has taken a key step in promoting reliable graphene sensing technology. The graphene biosensor developed is one of the representatives of the world's more advanced biosensors, and is an analytical testing field. Provides a whole new approach. "
Tsinghua University Professor Zhu Hongwei's team and Beijing Huada Zhibao Electronic System Co., Ltd. have jointly developed a graphene temperature and flow integrated sensor device. According to the application requirements of flow rate and temperature sensors for detection of thermal systems, they have studied the role and rules of graphene sensing to break through the key technologies of graphene materials used in heat meter flowmeters and develop graphene flow and temperature for detection of thermal systems. The sensor device solves the problems of scaling and high power consumption on the existing sensor surface, and forms a batch preparation capability, which is expected to be applied in large-scale thermal systems.
The team completed the research on the modulation of sensing performance of graphene wafer shape, size, surface / interface state, and developed a large-range, high-precision flow and temperature sensor through the design of a sensing process structure based on a graphene thin material. The measurement range of the flow sensor element is 0.01 ~ 6m3 / h, and the measurement accuracy is 0.005m3 / h; the measurement range of the temperature sensor element is 0 ~ 100 ° C, and the measurement accuracy is 0.02 ° C.
Based on graphene flow and temperature sensing materials, two expansion studies were carried out at the same time: 1) A new idea for achieving highly sensitive and flexible strain sensing was proposed, which was constructed by combining graphene with ultra-elastic ultra-thin polymer materials A class of prototype devices based on flexible sensors has been developed for manufacturing methods and processes of wearable-oriented sensors. It has explored several typical sensing applications such as strain, piezoresistance, torsion, volatile organic compounds, and sound waves. Detecting weak physiological signals such as pulse and speech, which are expected to be applied to mobile medical, wearable devices and other fields; 2) The diffusion characteristics of water in the pores of graphene layers have been studied, and an isotope labeling method has been developed to reveal water molecules The diffusion coefficient in graphene is 4 to 5 orders of magnitude higher than the diffusion coefficient of micron-sized channels in microporous membranes, which proves that water molecules can be transported ultra-fast, laying a foundation for the study of mass transfer characteristics based on graphene. The field of rapid filtration and separation shows broad application prospects.
United Kingdom
Researchers at the University of Southampton in the United Kingdom and the Japan Institute of Advanced Science and Technology have recently developed a graphene-based sensor. The sensor can detect indoor air pollution with low energy consumption.
This new sensor can sense carbon dioxide molecules and volatile organic compound gas molecules from construction, decoration materials, furniture and even home appliances. The concentration levels of these harmful chemical gases are generally in the parts per billion (ppb), which is difficult to detect with existing environmental sensing technologies, because these sensors can only detect such parts with a concentration of parts per million (ppm). gas.
When the graphene sensor developed by the research team is energized, individual carbon dioxide molecules can be adsorbed on the graphene material one by one, and its concentration can be detected at the molecular level. By monitoring the resistance of the graphene beam, the graphene material's adsorption and release of carbon dioxide molecules can be detected as a "quantized" change in resistance. In the experiment, the researchers detected carbon dioxide at a concentration of about 30 ppb in just a few minutes.
Researchers at the University of Glasgow in Scotland have designed a graphene-based transparent flexible capacitive touch sensor that not only provides touch detection, but also is equipped with a pressure sensing function. Because it is transparent, the tactile sensing layer can be stacked on a rigid or flexible solar photovoltaic (PV) cell to automatically power it during operation.
Ireland
Funded by the Science Foundation of Ireland, researchers at the Centre for Advanced Materials and Bioengineering (AMBER) and the School of Physics at Trinity College Dublin have recently successfully collaborated to add graphene to commercially available rubber, so that rubber retains its original mechanical properties At the same time, it has conductivity, which makes wearable graphene-rubber sensors.
The test results show that when the mixed rubber is stretched, the current flowing through the mixture changes greatly. Therefore, if the graphene-rubber mixture is embedded in clothing, it can sense even the smallest human activities such as breathing and pulse. The research opens the way for the development of rubber-based wearable sensors that can be used to monitor blood pressure, key movements and breathing.
In addition, graphene-rubber sensors have many potential uses, such as developing high-sensitivity airbags, medical devices to monitor body movements, early warning systems for sudden infant death and adult sleep apnea, and embedded clothing to monitor athletes The movement or rehabilitation of the patient.
(Source: Baidu Academic, Scientific Chinese, Electronic Enthusiast Network)