From chocolate bars to vehicle engines, computers, and even city apartments, you don’t have to look far to see things are getting smaller. For cheap and easy pill testing and hydrocarbon detection, the future of spectroscopy is here – and the future, is miniature.

This article considers the miniaturization of gas sensors from two perspectives: the testing of pharmaceuticals, and the detection of hydrocarbon.

Pill testing, simplified

In the rush of daily life it can be easy to confuse or mix up pills, especially if you or someone you care for is taking several medications. So how can you be sure the pill you’re about to take is the correct one?

We’ve designed some technology that could help with this issue. Also, the tool might one day be suitable for pill testing at music festivals and other events where other pill drugs are available.

In our experiments we have demonstrated how off-the-shelf mobile hardware can be used to identify pills. Soon we expect this hardware may be built into most smartphones.

How does it work?

The enabling technology, known as near-infrared spectroscopy, is not new. What is new is that it has been miniaturized.

The technology works by shining infrared light onto the pill. The pill absorbs and reflects some of the light depending on its chemical composition.
By measuring the spectrum of the reflected light, we can obtain a unique signature for this pill. By cross-referencing this signature against a database on known pills or chemicals we can identify the pill.

“near-infrared spectroscopy, is not new. What is new is that it has been miniaturized”

The technology does not damage the pill, since it simply shines infrared light for a couple of seconds.

It does not rely on the visual appearance of the pill at all. In our tests we could accurately differentiate between pills that look virtually identical.

Further accuracy improvements are expected soon, but at this stage we can say this technology allows for pill-testing to be done on the spot, using a mobile device. It’s no longer necessary to ship samples to a dedicated testing facility.

At the moment the technology has been tried on only about 60 pills that can be bought over the counter, such as painkillers, vitamins and other supplements. It could easily be extended to prescription medications.

We actually developed our prototype to be used on prescription and over-the-counter pills, as a way to make sure people are taking the correct medication. This work is being carried out as part of a broader Smart Hospital project to make hospitals safer and more efficient.

“our work has shown that environmental factors may affect the accuracy of the system, so it’s unlikely to be as accurate as in controlled lab settings”

For example, medication errors occur when nurses give the incorrect pill to patients in a hospital, or when patients take the wrong pill at home. Our technology has been designed to reduce such errors due to mislabelling or lack of labels.

Checking ‘other’ pills

It’s become clear that our technology also has the potential to check other types of pills and could be used in scenarios such as people attending music festivals, on-the-spot police checks, or any other situation.

But there are some potential problems here. Our work has shown that environmental factors – such as ambient light – may affect the
accuracy of the system, so it’s unlikely to be as accurate as in controlled lab settings.

Also, because our prototype works by cross-referencing to a database of known pills, it can be challenging for the system to identify homemade pills that may not exactly match the chemical composition in our database.

Still, there are a couple of ways to deal with this situation.

First, the system can provide a confidence rating, effectively saying that it has not seen a particular pill before, but it can report which pill it is most similar to.

Second, if we are interested in certain active chemical components in the pill, it can report which of those components are present in the pill, but not necessarily in what amounts.

The tech’s coming, ready or not

Technology has a habit of moving inexplicably quickly, and this is certainly the case with the pill testing market. Soon these changes will have an impact on the arguments used by the different sides of the pharmaceuticals-testing debate.

Our technology demonstrates the potential for making pill-testing a private matter, with no need for any taxpayer-funded testing at events. It is entirely conceivable that soon it will be possible to buy a pill-testing device that you can carry in your pocket and use where and when you choose.

Pill-testing proponents argue that it has the potential in its current form at festivals to be one last safeguard – a final line of defence, if you will – and source of advice before pills are consumed, or not, as may be the case.

“with the pill-testing technology maturing and being miniaturized even further, we expect within a few years to see widespread prototypes being used”

With the pill-testing technology maturing and being miniaturized even further, we expect within a few years to see widespread prototypes being used. While the hardware is quickly improving, the main challenge remains the analysis that we have developed to differentiate between pills.

We want to raise awareness about this technology and advise all camps in the pill-testing debate that they need to consider how to respond to this technology.

Pill-testing critics might need to consider ways to stop pill-testing given the availability of cheap testing devices. Should such devices be banned?

Pill-testing supporters need to consider that pill-testing may soon be possible outside well-staffed festival tents. Therefore, there is a need for new interventions, as well as a consideration of who maintains the pill database: government, industry, NGOs, or perhaps some crowdsourced approach?

One thing is for certain, from pill testing to detecting hydrocarbon, the technology certainly is getting smaller. When considering the miniaturization of gas sensors, it is exciting also to look at the components – based on Mid-IR spectroscopy – being developed by the European consortium.

Getting technical

In a H2020-project, MIREGAS, Technical Research Centre of Finland VTT Ltd and Tampere University of Technology teams, together with European partners, developed novel components for miniaturized gas sensors exploiting the principle of Mid-IR absorption spectroscopy. In particular, the main advances concerned the development of novel superluminescent LEDs for 2.65 µm wavelength, Photonic Integrated Circuits (PICs) with 1nm bandwidth for spectral filtering at Mid-IR, hotembossed Mid-IR lenses for beam forming and photodetectors for 2 to 3µm wavelengths. Silicon photonics PIC technology that was originally developed for optical communication applications allows for the miniaturization of the sensor. The components entail important benefits in terms of cost, volume production and reliability.

The market impact is expected to be disruptive, since the devices currently on the market are typically complicated, expensive and heavy instruments. The components developed by the consortium enable miniaturized integrated sensors with important benefits in terms of cost, volume production and reliability, which are instrumental features for the wide penetration of gas sensing applications.

“using the new technology, the wavelengths of light can be filtered more precisely and interfering gas components can be excluded”

The IR spectroscopy is a powerful tool for multigas analysis. Conventional sensors are based on the use of filters, spectrometers or tuneable lasers. MIREGAS project, has introduced breakthrough components, which enable multigas analysis using integrated solution. Moreover, using the new technology, the wavelengths of light can be filtered more precisely and interfering gas components can be excluded.

World-leading institutes

H2020 European consortium, MIREGAS, brought together worldleading European institutes and multinational companies. On the technology side, VTT Technical Research Centre of Finland Ltd coordinated the programme and provided Si PICs as well as photonics packaging and integration technologies. The Optoelectronics Research Centre at the Tampere University of Technology in Finland was responsible for developing innovative superluminescent LEDs, ITME (PL) for mouldable Mid-IR lenses and VIGO (PL) for Mid-IR detectors. Industrial partners Vaisala (FI), AirOptic (PL) and GasSecure (NO) brought their competences in the areas of gas sensing and Mid-IR sensor fabrication, and at the same time, validated the technologies developed by the consortium.

“Within this project, ITME was able to establish technology for low-cost mid IR optics development using moulding optics approach. We have developed several novel glasses transparent from visible up to Mid-IR range. We establish moulding processing that allow us to develop freeform optical components with optical surface quality for Mid-IR without further polishing. It allows to reduce cost of production first, but also to develop lenses in environment friendly matter since number of glass waste is dramatically reduces. Also grinding and polishing processes that require use of large amounts of water and polishing powders are totally redundant. We found also new materials for mould development that are low cost and can be processed with standard CNC machines. This way our technology becomes cost effective also for prototyping and short series of components. This breakthrough gave access for custom made free-form glass optics, even for SME companies,” said Professor Ryszard Buczynski, head of Department of Glass, ITME. “Now we verify the market potential of our technology and offer access to this technology as a custom service through ITME. After market validation, we plan to transfer this technology to other existing companies or establish spin-off company. Some venture funds and world-recognised companies have already expressed their interest in our innovations.”

Prof. Mircea Guina, the head of ORC team at Tampere University added: “At the start of the project, Mid-IR SLED technology targeting highbrightness and broadband operation simply did not exist. MIREGAS enabled an important scientific breakthrough; in fact, the project’s results represent the state-of-the-art, both in terms of power and wavelength coverage. Yet, what it is maybe the most important, contributed to creating a new European ecosystem based on combined expertise in Mid-IR optoelectronics and Si-photonics. We are just at the start of many other applications we will target with this powerful combination of technologies”.