Researchers from the Universities of Glasgow and Strathclyde built the ‘tongue’ using sub-microscopic slices of gold and aluminium, creating a checkerboard pattern of the two metals to act as ‘tastebuds’ for the whisky.
In tests using single malt whiskies from Glenfiddich, Laphroaig and Glen Marnoch (Aldi’s single malt brand), the tongue was more than 99% accurate, and was capable of distinguishing between the same whisky matured in different casks, and between the same whisky aged for 12, 15 and 18 years.
The scientists poured whisky over the ‘tastebuds’ – which are 500 times smaller than their human equivalents – and conducted a statistical analysis of the subtle differences in how the metals absorbed light, known as their plasmonic resonance.
Dr Alasdair Clark, of the University of Glasgow’s School of Engineering, explained that the artificial tongue acted in a similar way to its human equivalent.
‘Like us, it can’t identify the individual chemicals which make coffee taste different to apple juice, but it can easily tell the difference between these complex chemical mixtures,’ he said.
He added that the tongue was the first to use two different types of nanoscale metal tastebuds, ‘which provides more information about the “taste” of each sample and allows a faster and more accurate response’.
Although whisky was used in the experiments, the tongue could be used to taste almost any liquid, including wine, with Dr Clark highlighting its ‘obvious potential for use in identifying counterfeit alcohols’.
The research, conducted by engineers and chemists from the two universities, was supported by funding from the Leverhulme Trust, the Engineering and Physical Sciences Research Council, and the Biotechnology and Biological Sciences Research Council.
The findings are published as a paper entitled ‘Whisky tasting using a bimetallic nanoplasmonic tongue’ in Nanoscale, a journal of the Royal Society of Chemistry.
