Graphene sensors: introduction and market status - Page 22

Riptron, a spin-out company from the University of Manchester, has entered a partnership with China-based Tunghsu Optoelectronics to advance graphene sensors designed to measure the quality of air. The graphene-based sensors are expected to enter mass production shortly following the partnership between the two companies.

In this context, Riptron will secure around £1 million investment over two stages from Tunghsu Optoelectronics.

Researchers from Bar-Ilan University in Israel and Yale University in the U.S have reported on a novel device architecture comprising graphene Schottky diode varactors. The team assessed that such devices have great potential for optoelectronics applications.

graphically illustrated edge contact image

The team has shown that graphene varactor diodes exhibit significant advantages compared with existing graphene photodetectors, including elimination of high dark currents and enhancement of the external quantum efficiency (EQE).

Project "HEA2D", which started in 2016 and set out to investigate the production, qualities, and applications of 2D nanomaterials, recently demonstrated end-to-end processing chain of two-dimensional nanomaterials. The project is a collaboration between AIXTRON, AMO, Coatema, Fraunhofer and Kunststoff-Institut für die mittelständische Wirtschaft (K.I.M.W.).

It was stated that the "HEA2D" consortium successfully demonstrated an end-to-end processing chain of two-dimensional nanomaterials as part of its results. 2D materials integrated into mass production processes have the potential to create integrated and systemic product and production solutions that are socially, economically and ecologically sustainable. Application areas for the technologies developed and materials investigated in this project are mainly composite materials and coatings, highly sensitive sensors, power generation and storage, electronics, information and communication technologies as well as photonics and quantum technologies.

UK-based graphene technology company Paragraf has announced the close of its £12.8 million (over $16 million USD ) Series A round led by Parkwalk. The round also included investment from IQ Capital Partners, Amadeus Capital Partners and Cambridge Enterprise, the commercialization arm of the University of Cambridge, as well as several angel investors. The funding will aim to see Paragraf’s first graphene-based electronics products reach the market, transitioning the company into a commercial, revenue-generating entity.

Paragraf sets out to deliver IP-protected graphene technology using standard, mass production scale manufacturing approaches, enabling step-change performance enhancements to today’s electronic devices. The company’s first sensor products have reportedly demonstrated order of magnitude operational improvements over today’s incumbents. Achieving large-scale, graphene-based production technology may enable next generation electronics, including vastly increased computing speeds, significantly improved medical diagnostics and higher efficiency renewable energy generation as well as currently unachievable products such as instant charging batteries and very low power, flexible electronics.

Researchers at the U.S-based University of Rochester, along with colleagues at Delft University of Technology in the Netherlands, have designed a way to produce graphene materials using a novel technique: mixing oxidized graphite with bacteria. Their method is reportedly a more cost-efficient, time-saving, and environmentally friendly way of producing graphene materials versus those produced chemically, and could lead to the creation of innovative computer technologies and medical equipment.

From left to right:graphite (Gr), graphene oxide (GO), microbially‐reduced graphene oxide (mrGO), and chemically‐reduced graphene oxide (crGO)

"For real applications you need large amounts," says Anne S. Meyer, an associate professor of biology at the University of Rochester. "Producing these bulk amounts is challenging and typically results in graphene that is thicker and less pure. This is where our work came in". In order to produce larger quantities of graphene materials, Meyer and her colleagues started with a vial of graphite. They exfoliated the graphite-shedding the layers of material-to produce graphene oxide (GO), which they then mixed with the bacteria Shewanella. They let the beaker of bacteria and precursor materials sit overnight, during which time the bacteria reduced the GO to a graphene material.

Researchers from the Moscow Institute of Physics and Technology (MIPT) and Valiev Institute of Physics and Technology in Russia have demonstrated resonant absorption of terahertz radiation in commercially available graphene. The team declared this to be an important step toward designing efficient terahertz detectors, which would enable faster internet and a safe replacement for X-ray body scans.

Graphene-based transistor with a metal grating. Credit: Courtesy of the researchers

THz radiation, also known as T-waves, is considered difficult to generate and detect. This gave rise to the notion of a terahertz gap, which roughly refers to the 0.1-10 THz frequency band in the electromagnetic spectrum. There are no efficient devices for generating and detecting radiation in this range. Nevertheless, T-waves are very important for humanity: They do not harm the body and so could replace X-rays in medical scans. Also, T-waves could make Wi-Fi much faster and open the door to astronomical research that is thus far untapped .

Researchers at Osaka University have invented a graphene-based biosensor to detect bacteria such as those that attack the stomach lining and that have been linked to stomach cancer. When the bacteria interact with the biosensor, chemical reactions are triggered which are detected by the graphene.

To enable detection of the chemical reaction products, the researchers used microfluidics to contain the bacteria in extremely tiny droplets close to the sensor surface.

Researchers at The University of Texas at Austin have developed a graphene-based wearable device that can be placed on the skin to measure a variety of body responses, from electrical to biomechanical signals.

The device is so lightweight and stretchable that it can be placed over the heart for extended periods with little or no discomfort. It also measures cardiac health in two ways, taking electrocardiograph and seismocardiograph readings simultaneously. The electrocardiogram (ECG) technique, a method that records the rates of electrical activity produced each time the heart beats. is rather well-known. Seismocardiography (SCG), a measurement technique using chest vibrations associated with heartbeats, is a bit less so. Powered remotely by a smartphone, the e-tattoo is the first ultrathin and stretchable technology to measure both ECG and SCG.

Graphene Flagship partner, Emberion, will be launching a VIS-SWIR graphene photodetector at Laser World of Photonics, from 24 to 27 June in Munich, Germany. The linear array covers a wide spectral range, detecting wavelengths from the visible at 400nm into the shortwave infrared up to 1,800nm. Traditionally, it would require both silicon and InGaAs sensors to image across this wavelength range.

Emberion estimates that replacing a system using silicon and InGaAs sensors with its graphene photodetector would result in a 30% cost reduction.

Researchers at the International Iberian Nanotechnology Laboratory (INL) and Research Institute for Life and Health Sciences (ICVS) at the University of Minho in Portugal will develop a graphene-based device that allows the early diagnosis of malaria, in a fast and reliable way, and at an accessible cost.

Over the course of a year, both institutions will work to utilize the technology of graphene-based sensors, developed at INL.