G-FET

Researchers from Friedrich Schiller University Jena, CNM Technologies, NOXXON Pharma, APTARION Biotech and Radboud University Medical Center have developed graphene field effect transistor (GFET) sensors based on van der Waals (vdW) heterostructures of single-layer graphene layered with a molecular ≈1 nm thick carbon nanomembrane (CNM).

1 / 1Schematic illustration of the fabrication steps of the l-AP/PEG-CNM GFET sensors. Credit: Advanced Materials 

The CNM acts as an ultrathin molecular interposer between the graphene channel and the analyte and allows bio-functionalization without impairing the graphene properties including its charge carrier mobility. 

Archer Materials has announced that successfully miniaturized its Biochip graphene field effect transistor (gFET) design, reducing its size by 97% and significantly lowering fabrication costs. The development marks a significant step in Archer’s efforts to strengthen its semiconductor capabilities and expand its role in medical diagnostics.

This advancement, achieved in collaboration with Applied Nanolayers and AOI Electronics, enhances the chip’s readiness for integration in home testing devices for chronic kidney disease. 

An international group of scientists, including ones from the UK's University of Bath, Friedrich Schiller University Jena in Germany and the University of Pisa in Italy, recently set out to investigate the ultrafast opto-electronic and thermal tuning of nonlinear optics in graphene.

Opto-electronic modulation of third harmonic generation in a graphene field-effect transistor. The illustration includes a sketch and a microscopic optical image of the device. Image credit: University of Bath

Nonlinear optics explores how powerful light (e.g. lasers) interacts with materials, resulting in the output light changing color (i.e. frequency) or behaving differently based on the intensity of the incoming light. This field is important for developing advanced technologies such as high-speed communication systems and laser-based applications. Nonlinear optical phenomena enable the manipulation of light in novel ways, leading to breakthroughs in fields like telecommunications, medical imaging, and quantum computing. Graphene's exceptional electronic properties, related to relativistic-like Dirac electrons and strong light-matter interactions, make it promising for nonlinear optical applications, including ultrafast photonics, optical modulators, saturable absorbers in ultrafast lasers, and quantum optics.

An international team of researchers, including scientists from University of California San Diego, Chinese Academy of Sciences, University of Texas Medical Branch and University of Illinois Urbana-Champaign, has developed a handheld, non-invasive graphene-based device that can detect biomarkers for Alzheimer’s and Parkinson’s Diseases. The biosensor can also transmit the results wirelessly to a laptop or smartphone.

The biosensor consists of a chip with a highly sensitive transistor, made of a graphene layer that is a single atom thick and three electrodes–source and drain electrodes, connected to the positive and negative poles of a battery, to flow electric current, and a gate electrode to control the amount of current flow. Image credit: UCSD

The team tested the device on in vitro samples from patients. The tests reportedly showed the device is as accurate as other state-of-the-art devices. Ultimately, researchers plan to test saliva and urine samples with the biosensor. The device could be modified to detect biomarkers for other conditions as well.

Archer Materials has had its advanced graphene field effect transistor (“gFET”) chip design validated by a commercial foundry partner in the Netherlands with a whole four-inch wafer run.
 

The new advanced gFET device designs have been fabricated and the whole wafer run foundry process was reportedly successful. The electronic and spectroscopic characteristics of the gFET chips, and the foundry fabrication process yield, are said to be consistent with what Archer expected. The gFET chips are also compatible with Archer’s biochip system platform.

Researchers from the University of California Santa Cruz, University of Manchester and Japan's International Center for Materials Nanoarchitectonics and National Institute for Materials Science have used a scanning tunnelling microscope to create and probe single and coupled electrostatically defined graphene quantum dots, to investigate the magnetic-field responses of artificial relativistic nanostructures.

Trapped electrons traveling in circular loops at extreme speeds inside graphene quantum dots are highly sensitive to external magnetic fields and could be used as novel magnetic field sensors with unique capabilities. Although graphene electrons do not move at the speed of light, they exhibit the same energy-momentum relationship as photons and can be described as "ultra-relativistic." When these electrons are confined in a quantum dot, they travel at high velocity in circular loops around the edge of the dot.

Researchers from Graphenea, Ikerbasque, BCMaterials, Center for Cooperative Research in Biomaterials (CIC biomaGUNE) of the Basque Research and Technology Alliance (BRTA), University of the Basque Country UPV-EHU, University of Trieste and Universidade da Coruña recently reported a graphene field effect transistors (GFET) array biosensor for the detection of SARS-CoV-2 spike protein, using the human membrane protein involved in the virus internalisation: angiotensin-converting enzyme 2 (ACE2).

By finely controlling the graphene functionalization, by tuning the Debye length, and by deeply characterizing the ACE2-spike protein interactions, the team managed to detect the target protein with an extremely low limit of detection (2.94 aM).

Researchers at Tokyo Institute of Technology (Tokyo Tech) and Toshiba Corporation recently demonstrated how graphene-based olfactory sensors could detect odor molecules depending on the design of peptide sequences. They showed that graphene field-effect transistors (GFETs) functionalized with designable peptides could be utilized to develop electronic devices that imitate olfactory receptors and then emulate the sense of smell by selectively detecting odor molecules.

Olfactory sensing is an integral part of many industries like food, cosmetics, healthcare, and environmental monitoring. Currently, most commonly utilized methods for detecting and evaluating odor molecules is called gas chromatography–mass spectrometry (GC–MS). While GC–MS is effective, it has certain limitations like confined sensitivity and heavy setup. As a result, researchers are in the search of user-friendly and highly sensitive alternatives.

In June 2022, Graphenea launched its latest product out of its Graphene Foundry, the mGFET, fully-packaged mini graphene-based field effect transistors.

Graphenea now updates that the market demand for these products has been excellent, and it has run out of stock. The company is now working to produce more mGFET devices and restock.

The mGFETs are Graphenea's highest value-chain products, which are manufactured and packaged in chip carriers, and can be used together with the Graphenea Card for seamless sensor development (which was released earlier in 2022, and has also seen very good reception in the industry).

Graphenea launched two new products out of its Graphene Foundry, which they call mGFET or miniGFET. These are Graphenea's highest value-chain products, which are manufactured and packaged in chip carriers, and can be used together with the freshly released Graphenea Card for seamless sensor development.

The mGFET is available from $99, and as it is a fully-package device, it is ready to be integrated into standard electronics. Order volume can range from a few devices for early prototyping, to JEDEC trays with hundreds of devices which are compatible with automated pick & place routines.