Graphene sensors: introduction and market status - Page 56

Aixtron announced today that Osaka University in Japan placed an order for a 4" AIXTRON BM Pro system. The University will use the new equipment to produce carbon nanotube (CNT) and graphene structures for bio-sensors. The aim is to combine graphene field-effect transistors with organic chemicals, such as antibodies, antigens and aptamers to allow electrical detection of specific proteins. The BM Pro system will also be used to produce carbon nanotubes for micro-electromechanical-systems (MEMS) and energy storage devices.

Researchers from the HRL labs in California have developed the world’s first graphene-based square-law millimeter detectors. These new detectors sport the highest linear dynamic range (over 60 dB) ever measured in a semiconductor detector. They say that this could lead to better high-bandwidth communications, imaging and radar systems.

The researchers say that their new graphene-based FET detectors out perform the best CMOS or SiGe bipolar detectors by more than 30 dB (linear dynamic range).

Researcher from MIT discovered that graphene's basic properties (chemical reactivity, electrical conductivity and others) can vary dramatically based on the substrate material it is placed on. When placed on silicon dioxide, graphene becomes functionalized when exposed to certain chemicals, but when the substrate is boron nitride, the graphene is inert to the same chemicals.

The research, funded by the US Office of Naval Research, means that you can control the graphene ability to create chemical bonds - using different underlying materials.

Researchers developed a new graphene based film that can detect trace amounts of environmental contaminants. The film is made from semiconductor-graphene-metal, by taking a graphene sheet and depositing metal (silver) nanoparticles and semiconductor titanium dioxide on either side.

The film can be used to test water quality, and this requires precise control over metal deposition and size. The film is capable of selectively splitting hydrogen and oxygen.

Researchers from the University of Illinois and Dioxide Materials have showed that randomly stacked graphene flakes can make an effective chemical sensor. The flakes were fabricated by placing bulk graphite in a solution and bombarding it with ultrasonic waves that broke off thin sheets. This solution was filtered to produce a graphene film - made from stacked flakes. The flakes were used as the top layer of a chemical sensor. Movement of electrons through the film produced an electrical signal that flagged the presence of a test chemical.

According to the researchers, this new sensor is more reliable than existing sensors made from carbon nanotubes or graphene crystals. The researchers think that this is due to the fact that defects in the carbon-lattice structure near the edge of the graphene flakes allow electrons to easily "hop" through the film.

Researchers from Rensselaer Polytechnic Institute have discovered that graphene foam can outperform leading commercial gas sensors in detecting potentially dangerous and explosive chemicals. The foam is made from several graphene sheets (grown on Nickel, which was later removed) and is flexible, rugged and retains graphene's important properties.

The new sensor successfully and repeatedly measured ammonia (NH3) and nitrogen dioxide (NO2) at concentrations as small as 20 parts-per-million. The graphene foam sensor is about the size of a postage stamp and the thickness of felt. Here's a video discussing the production method of the graphene foam:

Scientists suggest a new way to measure the Kilogram and Ampere units - using Graphene. These units can be measured using the quantum hall effect, and they suggest the Graphene may be the best conductive material for the job - it can be used to measure the units up to an uncertainty of just 86 parts per trillion.

NPL researchers used graphene to make the most precise measurements of the quantum Hall effect ever made. It turns out that the quantum Hall effect in graphene is very robust and easy to measure.

The National Science Foundation (NSF) awarded a research grant to a Stevents Institute of Technology researcher to study the properties of graphene nanoribbons for use in infrared (IR) detection.

This funded research is to investigate the properties of actively controlled graphene nanoribbon arrays that researchers can "tune" for use in IR detectors covering an ultra-wide spectral range. In their awarded research, Dr. Yang and Dr. Strauf investigate nanoelectromechanical devices employing graphene nanoribbons to significantly improve IR detection schemes. Current IR detectors experience both limitations in their spectral range, for those that rely on the fixed IR absorption properties of detector materials, or their general sensitivities, in the case of tunable thermal detectors. The proposed concept offers the unique possibility of achieving high sensitivity across a wide spectral range with a single detection system.

MIT announced the creation of the MIT/MTL Center for Graphene Devices and Systems (MIT-CG). This is an interdepartmental center which is part of the Microsystems Technology Laboratories (MTL) with an aim to bring together MIT researchers and industrial partners to advance the science and engineering of graphene-based technologies.

The MIT-CG will research the basic physical properties of graphene and will also explore advanced technologies and strategies that will lead to graphene-based materials, devices and systems for a variety of applications (including graphene-enabled systems for energy generation, smart fabrics and materials, radio-frequency communications, and sensing).