An artificial ‘tongue’ which can taste subtle differences between drams of whisky, and could help cut down on the counterfeit alcohol trade, has been developed in research involving the University of Strathclyde.
A newly-published paper describes the construction of the device, which uses the optical properties of gold and aluminium to test alcohol samples.
Sub-microscopic slices of the metals, arranged in a checkerboard pattern, act as the ‘tastebuds’ in the artificial tongue. The researchers poured samples of whisky over the tastebuds – around 500 times smaller than the ones in the human body – and measured how they absorb light while submerged.
The researchers identified different types of whisky by analysing the subtle differences in the way the metals in the artificial tongue absorbed light – a phenomenon known as plasmonic resonance.
The tongue was able to taste the differences between the drinks with greater than 99% accuracy. It was capable of picking up on the subtler distinctions between the same whisky aged in different barrels, and tell the difference between the same whisky aged for 12, 15 and 18 years.
Central to the development of the artificial tongue is the chemical modification of surfaces with molecules which can detect differences in hydrophobicity, or 'fattiness'. This is then used to develop a unique optical profile for each whisky.
Professor Glenn Burley, of Strathclyde’s Department of Pure and Applied Chemistry, was a member of the research team. He said: “This work is a great example of a collaboration spanning organic chemistry and nano-engineering. We are now looking forward to working with the whisky industry to optimise the sensitivity and thoroughness of the device."
The team, led at the University of Glasgow, used the tongue to take samples of three types of whisky: Glenfiddich; Glen Marnoch and Laphroaig.
The paper, titled Whisky tasting using a bimetallic nanoplasmonic tongue, has been published in Nanoscale.
The research was supported by funding from the Leverhulme Trust, the Engineering and Physical Sciences Research Council, and the Biotechnology and Biological Sciences Research Council.