Engineers and chemists from Scotland’s University of Glasgow and the University of Strathclyde have developed an artificial tongue to accurately distinguish among a variety of whiskies.

The reusable artificial tongue, which could potentially be used to prevent alcohol counterfeiting, is composed of multiplexed aluminum and gold nanoarrays arranged in a checkerboard-like sequence. The nanoarrays behave like human tastebuds within the bimetallic tongue, generating two distinguishable resonance peaks for each sensing region.

To demonstrate how the artificial tongue works, researchers poured whisky samples over the tastebuds, which are roughly 500 times smaller than human tastebuds, and measured how the tastebuds absorbed light while submerged in the different whiskies. The extremely faint differences in how the metals used within the artificial tongue absorbed light — called plasmonic resonance — generated distinct “fingerprints” for each whisky, thereby enabling the team to distinguish among the different types of whiskies.

Sampling whiskies from brands such as Glenfiddich, Glen Marnoch and Laphroaig, the tongue reportedly detected the differences among the whisky types with over 99% accuracy. Likewise, the artificial tongue could reportedly detect the subtler distinctions in the same whisky aged in different barrels as well as among whiskies aged for 12, 15 and 18 years.

“We call this an artificial tongue because it acts similarly to a human tongue — 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," said the study’s lead author, Dr. Alasdair Clark of the University of Glasgow’s School of Engineering.

In addition to potential applications for detecting counterfeit alcohols, the team believes that if incorporated into a small, portable device, the artificial tongue could also have applications for poison identification or environmental monitoring of bodies of water, among other uses.

“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," said Dr. Clark. "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 paper, titled ‘Whisky tasting using a bimetallic nanoplasmonic tongue,’ is published in the Royal Society of Chemistry’s journal Nanoscale.