Artificial tongue can ‘taste’ if whisky is fake

An artificial tongue that can detect chemical differences between whiskies could help tackle the counterfeit trade, according to its developers.

The team from the University of Glasgow describe in the journal Nanoscale, how they built the ‘bimetallic sensor’, which exploits the optical properties of gold and aluminium to test whisky and other alcoholic drinks.

Sub-microscopic slices of the two metals, arranged in a checkerboard pattern, acted as the taste buds in the artificial tongue. The scientists poured samples of whisky over the nanoscale sensors – which are about 500 times smaller than a human taste bud – and measured how they absorbed light while submerged.

Analysis of the subtle differences in how the metals in the artificial tongue absorb light – what the scientists call their plasmonic resonance – allowed the team to identify different types of whiskies. The team used the reusable tongue to test a selection of whiskies including Glenfiddich, Glen Marnoch and Laphroaig.

The device was able to taste the differences between the whiskies with greater than 99 per cent accuracy, and could even detect subtler distinctions between the same whisky aged in different barrels, and detect whether the same whisky had been aged for 12, 15 or 18 years.

Counterfeit whisky is an increasing problem, with a study of rare Scotch whiskies last year at the East Kilbride-based Scottish Universities Environmental Research Centre (SUERC) finding that a third were fake. That study used laboratory-based advanced radiocarbon dating techniques to analyse samples.

Dr Alasdair Clark of the University of Glasgow’s School of Engineering (pictured), who is the lead author of the paper, said the team isn’t the first to make an artificial tongue is the first to make a single artificial device that uses two different types of nanoscale sensors, increasing its sensitivity.

“While we’ve focused on whisky in this experiment, the artificial tongue could easily be used to taste virtually any liquid, which means it could be used for a wide variety of applications. In addition to its obvious potential for use in identifying counterfeit alcohols, it could be used in food safety testing, quality control, security – really any area where a portable, reusable method of tasting would be useful.”

The approach could be used to create portable detection devices “for applications in a point of care diagnostics, counterfeit detection in high-value drinks, environmental monitoring, and defense,” concludes the paper.