Against tea counterfeits: KIT develops "electronic nose" that can sniff out different plants.

  • chair:

    Marco Krefting
  • place:

    Badische Neueste Nachrichten (BNN) vom 17.01.2022
  • Date: 2022

  • Anyone who wants to distinguish between plants in nature needs a lot of experience, an identification book, or a good nose: In this respect, there could soon be technical support in the literal sense. KIT wants to use an "electronic nose" to unmask counterfeits of expensive teas, for example. The sensor is trained with different mints. In the future, an "electronic nose" will help distinguish between certain plants. This could, for example, unmask counterfeits of expensive teas, says Christof Wöll from the Institute for Functional Interfaces at the Karlsruhe Institute of Technology (KIT). An attachment for smartphones is also conceivable, he says, so that people have the right sniffer with them when searching for plants in nature. "The cell phone then serves as a data center." The researchers cite medical diagnostics and quality control in pharmaceuticals as other possible applications. Scents are to be deposited on the surface of twelve special sensors, each consisting of two electrodes with a quartz crystal. This changes their so-called resonance frequency; the data is used to create a kind of fingerprint of the respective scent.

    In comparison, the human nose has around 350 different receptor types, says Wöll. Theoretically, this allows us to distinguish between about 100,000 different odours. Dogs succeed with about one million smells, says the physicist. "Our goal is to beat the human and get to the dog."
    Next up are the truffles

    The scientists have practised the "electronic nose" with machine learning methods and six different types of mint, including classic peppermint, horse mint and catnip. Next, perhaps, could be training with truffles, Wöll said.

    According to him, the developers are currently thinking about founding a company that develops concrete devices for the application. Engineers are also in demand here. Ultimately, the envisaged supplements for mobile phones, for example, can be produced for a few euros - and are thus much cheaper and more portable than, for example, large systems for so-called mass spectrometry.

    Electronic noses" have been built for decades and used in food production and industry, among other things. KIT has also been working for some time on making such odour sensors as suitable as possible for mass and everyday use.

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