Move over Gene Simmons. Your reign as king of the tireless tongue is over. Researchers in Brazil and Wales have developed an indefatigable electronic tongue that can actually taste subtle differences in a variety of liquids. The "robo-tongue" can detect sweet, sour, bitter and salty characteristics in liquid products in which consistent taste is critical to manufacturers, such as mineral water, coffee, wine and tea.

When detecting those taste attributes, the robo-tongue is an order of magnitude more sensitive than the human tongue. It distinguished between Cabernet Sauvignons of different years from the same winery, sensed low levels of impurities in water and perceived sugar and salt at concentrations too low for human taste buds to detect.

Professor Martin Taylor, head of the molecular electronics research group at the University of Wales in Bangor, says there is a strong possibility the techno-tongue could detect other tastes.

The tongue, which actually fits on a microscope slide, measures the electrical response through a thin layer of organic matter spread over a pair of fingerlike electrodes when it is immersed in liquid. Taylor and Antonio Riul of the agricultural instrumentation research unit of Brazil’s Ministry of Agriculture, Livestock and Food Supply in S‹o Carlos recently patented the device. The tongue took three years to develop and won the S‹o Paulo governor’s prize for the most innovative invention in 2001.

The miniature device could eventually replace human testers in the coffee and wine industries, but more immediately it will help reduce their workload when real taste buds wear out, says Taylor. The electronic tongue can be washed and reused from liquid to liquid, whereas a human tongue can become overly saturated with a particular taste and lose effectiveness.

Wine tasters won’t lose their day jobs anytime soon, tough. Human taste buds are still preferable for detecting the myriad subtle and unique differences in fine wine and whiskey.