1) Graphene is a potential substrate for next generation mid-IR sensors

A paper in Nature Materials earlier this month has published research into the use of graphene as a substrate for mid-IR sensors.

The work has been published by Yale University and Barcelona’s Institute of Photonics Sensors, who have created a graphene-based sensor operating at 12.2 µm and consists of arrays of plasmonic resonators. Measuring just 5 µm by 5 µm, the devices have shown good low-noise performance at room temperature, without any cooling.

It has been known the excitation and decay of graphene plasmons can produce a significant increase in charge-carrier temperature, allowing temperature changes from this to be converted to an electrical signal for mid-infrared applications. However, the modest thermoelectric coefficient and weak temperature dependence of carrier transport in graphene hinder this goal. The ICFO researchers say that they have been able to boost sensitivity by exploiting the resonant coupling between mid-infrared light and graphene plasmons.

For more, the original paper (paywall) can be accessed here.

2) IR set to help improve yields in agriculture and reduce pollution

As populations have grown, the use of phosphates and oil based fertilisers have been key to helping populations be fed. The problem is, they are also polluting, creating runoff into streams and  rivers that then clog the stream with weeds and algae – killing marine animals.

In this month’s Nanalyze, IoT’s use in agriculture is covered, reporting the young startup American Robotics is using drones equipped with IR sensors that can determine crop health allowing. This would ultimately allow farmers to minimise fertiliser use to only where it is needed.

For more, the Nanalyze article can be found here.

3) Biofuel use by airlines

Several publications have reported on independent projects to reduce the effect of air travel on climate change by using biofuels. United has committed to cutting its emissions in half by 2050 using biofuels, with Quartz reporting on India’s plans trials with biofuels and Bloomberg reporting (syndicated here in the Jakarta Post) that JetBlue and Cathay Pacific are planning large scale trials in 2019 and 2020.

The industry accounts for c.2 per cent of the world’s carbon emissions and is growing rapidly and the airport LAX, plus three in Scandinavia (Oslo, Stockholm and Bergen) offer biofuels to blend into existing fuel supplies. As of June, more than 130,000 commercial flights have been powered by biofuel, according to the IATA.

As our recent blog highlighted, the need to ensure the right fuel is used is crucial, with fuels sourced from soy and palm oil being virtually as polluting as tar sands. The use of sensors – most naturally mid-IR-based ones will be crucial in understanding testing fuel and ensuring airlines are defrauded.

This need for fuel testing via IR sensors will also be vital for cars and engine health, with the Sunday Times reporting this month that the engines in over 600,000 cars (in the UK alone) will be damaged by the proposed inclusion of 10% bioethanol in petrol (aka E10 fuel). This particularly highlights the risk that using the wrong fuel will have for motorists, and therefore the need to only use reputable sources of biofuels, where testing is done regularly.

4) 3rd generation biofuels research picking up

As per our recent blog, the development of new biofuel technologies have slowed.

One of the big hopes was algae-based fuels – which aren’t a food crop, don’t require land to be used, and can be grown in industrial processes. Although microalgal biofuels have potential advantages over conventional fossil fuels, high production costs limit their application in the market.

A recent paper in Biotechnology for Biofuels, by researchers at Michigan State University in America, has made significant steps forward here – developing bio-flocculation and incubation methods for the marine alga, Nannochloropsis oceanica CCMP1779, and the oleaginous fungus, Mortierella elongata AG77, which has resulted in increased oil productivity.

The scientists believe that these two species, with their available genomes and genetic engineering tools for both species opens up new avenues to improve biofuel productivity and allows for the engineering of polyunsaturated fatty acids.

They’re not the only ones focusing on this area with Exxon Mobil recently pledging to produce 10,000 barrels of algal-based biofuels by 2025.

Again, the cost of doing so will be significantly high and therefore there will be an incentive for some to create counterfeit fuels based on cheaper crops (palm oil, soy) that cause as much if not more damage to the environment than producing fuel from crude. Low-cost testing will be essential and Mid-IR sensing technologies will be essential here.

5) The potential of infrared sensing devices in non-invasive diabetes tests

The rise of type-2 diabetes in the western world has been scarily rapid.

A few figures (for the UK alone – souce NHS) that show the scale of diabetes in general:

  • The cost of treating the condition and its complications is £17.5 billion per year.
  • Including other economic factors such as reduced lifespan increases the cost to more than £23 billion
  • Approximately 850,000 people have the disease.
  • The vast majority of this cost is for type-2 (weight- and lifestyle-related) diabetes

And it’s set to get worse. A peer-reviewed 2012 study by the York Health Economic Consortium suggests this will rise to demand 17% of the NHS budget, with treatment costing £30.4 billion.

But, with a healthy diet and exercise, the body’s demand for insulin can be reduced to help reverse diabetes. Early diagnosis is therefore critical, as is the correct monitoring of blood sugar levels for treatment – yet these all require regular blood tests to be performed.

A paper published in August in the journal Current Research in Diabetes and Obesity has evaluated IR sensors (both near and mid-IR) for use, highlighting that while its penetrace may be lower than near IR, mid-NIR bands possible advantage of Mid-IR bands produced by glucose, as well as other compounds, are sharper than those of NIR, which are often broad and weak.

6) Using Mid-IR sensing for screening the quality of medicines

The highly respected British Medical Journal has published a paper by researchers from the Wellcome Trust, Oxford University, Georgia Institute of Technology and Ohio State University analysing the effectiveness of over 40 different field-detection devices (from $10 to $20,000) in screening the quality of medicines.

14 IR and Mid-IR devices were included in this and have performed well with the paper stating “Spectral data have been successfully acquired through transparent blister packaging using six experimental samples.Quantitation of acetylsalicylic acid, ascorbic acid and caffeine in tablets gave results comparable with a reference benchtop Fourier Transform-Near-Infrared (FT-NIR) instrument.”

You can read the paper here.