Trend Sensors for digital smell applications By IDTechEx analysts C


onsumer technology can imitate many human senses: cameras to see, microphones to hear and touch-sensitive screens to feel, but what about scent?


The opportunities for digital smell could be vast and there are gas sensor technologies available today that will detect and identify scent. Animal-kingdom noses are full of


receptors that respond to gas mixtures and, over time, the brain learns to recognise a given smell. Today’s gas sensors are designed to digitise smell by imitating the human nose and brain. Electronic noses, or e-noses, require a period of training. They combine arrays of gas sensors with machine-learning algorithms that can identify patterns in response to a specific smell. The capabilities of miniaturised sensors and machine-learning software have been growing and have now reached a level of commercial readiness to create a digital smell industry. The digitisation of smell would be


an exciting addition to the sensing capabilities of consumer electronics. The technology has historically had a reputation for being over-hyped, but off-the-shelf devices represent the real progress made by the sector, largely been driven by innovations in the fundamental gas sensor technology required, in parallel with the maturity of machine-learning software. The use of arrays in e-noses creates


an opportunity for multiple types of gas sensor technologies. Data from well-known sensors such as metal oxide, electrochemical, infra-red, photoacoustic and others can be used by software looking to quantify gas mixtures. At the same time, advanced materials can form ultra-miniaturised sensors with the potential for integration into smartphones and wearables.


Some


manufacturers are beginning to incorporate gas sensors into white goods, with others soon expected to follow suit


More applications Food and drink are another obvious source of smells and a key application for e-noses. For example, the source of an aroma profile, or differences in smell between similar foods, is poorly understood. On the other hand, measuring gases given off by food as it deteriorates or becomes contaminated offers a way to maintain food quality and ensure safety. It could even help tackle food waste, with smell data offering an alternative to ‘best before’ dates. At an industrial level, ensuring


product consistency and quality control could also use smell sensors more broadly, which could threaten the existing supply chain of lab-bench equipment used in this area. Commercial devices suitable for


integration into smart-home goods and factories are just now emerging to monitor food and drink. Some manufacturers are beginning to incorporate gas sensors into white goods, with others soon expected to follow suit.


Just a smell? Beyond quantifying smell, many new e-nose technologies are targeting more


04 November 2022 www.electronicsworld.co.uk


sensitive and selective measurement of air quality than existing gas sensors. These capabilities are now being built into smoke detectors, including premises and perimeter alarms. There is growing interest in air


quality and its impacts on health, particularly long exposure to low concentrations – this is likely to fuel demand for e-noses. The success of such applications in the smart city and home sectors will arguably rely on effective marketing by OEMs, with this being a major barrier to mass- market adoption in the medium term. However, there are still e-nose


technology challenges. For example, the use of lower-cost and poor- sensitivity commoditised sensors and higher-value software places a significant burden on training the artificial intelligence required. And, the inherently higher performance hardware for e-noses, such as printed carbon nanotubes, are not yet manufacturable at scale and are still looking for high-volume applications. Furthermore, to date, the


infrastructure to train e-noses and share the data is limited. Whilst images are simplified into an RGB format, there is not yet an equivalent for smell. This challenge has been identified by some, such as Aryballe, but before the digital smell industry can reach its full potential, there needs to be standardisation.


More information The latest IDTechEx report, “Gas Sensors 2022-2032: Technology, Opportunities, Players, and Forecasts”, compares and benchmarks over 15 different gas sensor technologies that can be used in e-nose systems, but also other applications such as air quality, automotive and safety.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44