Graphene sensors: introduction and market status - Page 27

MIT engineers recently managed to create cell-sized robots that could collect data about their environment, but were quite tricky to manufacture. Now, the team has found a way to mass produce these synthetic cells (syncells) through controlled fracturing of graphene.

The previously developed MIT robots were so small, that there was no point trying to steer them, but they could still sense and observe, scanning their surroundings and storing data for long periods of time. Later, they could be filtered out and analyzed to get a reading of water quality, for example, or biomarkers for disease in a patient's bloodstream.

The Graphene-Info team attended this year's Graphene Week, organized by the Graphene Flagship in San Sebastian, Spain, 10-14 September 2018. The event attracted over 600 visitors from all over the world, and was extremely well organized.

While the talks and lectures were clearly scientifically-oriented, the commercial angle was also evident and many institutes and companies were there to show their recent product advancements. The Graphene Flagship's booth held a fascinating array of exhibits: graphene-enhanced retina and neural prosthesis (biomedical devices) by the ICN2 as a part of Braincom, Airbus' graphene composite for the leading edge of the tail of the Airbus A350, Nokia, Ericsson and AMO's graphene-based modulators and photodetectors for optical communications, a prosthetic robotic hand enhanced with graphene nerve sensors by the IIT, University of Cambridge's insole graphene-based pressure sensor and more.

Paragraf, the UK-based graphene technology development company, has announced the opening of an R&D facility in Cambridge. This follows the May 2018 announcement regarding seed investment of £2.9 million. The new site represents a turning point for graphene-based technologies, according to Paragraf, which it hopes will drive large-scale development of mass-market, graphene-based electronic devices.

Paragraf says its proprietary production technique overcomes the quality, contamination and reproducibility barriers faced by other graphene production methods. The customized equipment at the Cambridge facility will also allow Paragraf to convert its laboratory research into novel products, including next generation sensors, solid state electronics and energy storage cells.

Archer Exploration has announced that it has entered into a legally binding Material Transfer Agreement (MTA) with a leading German biotechnology company, regarding Archer’s graphene-based biosensor development activities with The University of Adelaide ARC Graphene Hub.

The Agreement involves the transfer of materials between Archer and the Partner for use in the development of electrochemical biosensors for the semi-quantitative detection of disease state markers. The materials to be used include those held in the inventory of the Partner (e.g. infectious disease antigens, antibodies, disease state sera, coupling and assay reagents) and materials in the inventory of Archer’s wholly owned subsidiary Carbon Allotropes (e.g. graphene, ink formulations, and printed graphene electrodes).

Sweden-based Graphmatech develops and produces novel graphene-based nanocomposite materials, under the Aros Graphene brand. The company recently secured an investment from ABB and Walerud Ventures, and the company's CFO, Bjorn Lindh, was kind enough to answer a few questions we had to him.

Q: Thank you for your time Bjorn. Can you give us a short introduction to Graphmatech's Aros Graphene materials, and how it differs from other graphene materials on the market?

Graphmatech has invented the novel material, Aros Graphene that keeps most of graphene's features, while making it easy to use in large industrial scales by preventing agglomeration, which is a key challenge for the use of graphene. Aros graphene is produced in powder form and can be used as additive, as coating or even in 3D-printing. The market introduction and launch of first products, filaments and thermal paste, will be introduced to the market in 2019.

A new study by KGI, UC Berkeley and Nanomedical Diagnostics researchers illustrates the impact of a graphene-based biosensors in identifying the circulating biomarkers of aging.

As a way to replace conventional assays, the research team presented a new portable digital device for biosensing based on functionalized graphene that can be employed for any click-able application. The lab-on-a-chip technology called Click-A+Chip is designed for facile and rapid digital detection of azido-nor-leucine (ANL)-labeled proteomes present in minute amount of sample.

MIT and Graphenea have developed an array of graphene sensors for sensitive and selective detection of ammonia. The array consists of 160 graphene pixels, allowing large statistics that result in improved sensing performance. The sensors are extensively tested for various real-life operational conditions, which seems to be a step forward to practical use.

The sensors are built by attaching porphyrins, a class of organic molecules, to the graphene surface. Porphyrins are particularly well-matched to graphene sensors because they provide excellent sensitivity while producing minimal perturbation to graphene’s outstanding electrical properties. When ammonia molecules attach to porphyrins, the compound becomes a strong dipole that changes electrical properties of the graphene. This electrical change is detected as a sign of the presence of ammonia.

An EU-funded project called the SGPCM project ("Switching Graphene-plasmon with Phase-Change Materials") is focusing on the unique capabilities of graphene plasmons to transport and control light emissions at spatial scales far smaller than their wavelength. This project is working on developing ways to use graphene efficiently in novel optical technologies with potential applications in medical imaging, biosensing, signal processing and computing.

Plasmons are quasiparticles that form the smallest quantum of plasma oscillations just as a photon is the smallest quantum of light. Graphene plasmons interact strongly with light and can therefore be used to guide it in entirely novel ways, opening pathways to the development of promising new technologies. They can be exploited in countless applications, including for infrared biosensing and absorption spectroscopy to identify the chemical information of biomolecules by detecting their vibrational fingerprints, and for sub-wavelength optical imaging, which enables the imaging of details much smaller than the wavelength of the illuminating light.

Liquid X Printed Metals, an advanced material manufacturer of functional metallic inks, has announced a collaboration effort with Bonbouton (a company focused on developing thermal sensing applications using a smart textile platform) to build graphene-enhanced temperature and pressure sensors directly on textiles using additive manufacturing techniques.

Through Bonbouton's inkjet-printable graphene technology, licensed from the Stevens Institute of Technology, the Company is developing thin and mechanically flexible sensors for wearable physiology monitoring. This gives consumers wearable personal health options that are unobtrusive, comfortable and attractive, while still enabling the collection of accurate, precise and useful data.

Researchers from ICFO and Yale have used graphene to efficiently detect mid-infrared light at room temperature and convert it into electricity. Detecting infrared light is of major importance for current applications in spectroscopy, materials processing, chemical, bio-molecular and environmental sensing, security and industry since the mid-infrared spectral region is the range where characteristic vibrational transitions and rotational excitations of many important molecules occur.

Schematic of the proposed device, composed of graphene-disk plasmonic resonators connected by quasi-1D graphene nanoribbons

These vibrational and rotational excitations of many molecules, including hazardous and biological molecules, have frequencies that are found in the mid-infrared, which can be monitored by observing the absorption of light in this specific spectral range. However, currently available mid-infrared detectors are very inefficient, except those that can operate at cryogenic temperatures, because they incorporate superconducting elements. Thus, this low temperature limitation is a major drawback in having detectors integrated in devices for consumer products.