New generations of sensors, which can consist of polymers, sound acoustic waves or, as with the robot sommelier, infrared rays, have become faster and more sensitive, says Nathan Lewis, a chemistry professor at Cal Tech. NASA's Jet Propulsion Lab built an e-nose (for which Lewis' lab developed the original sensor technology) to fly on the space shuttle and the International Space Station as a first-alert indicator of the dangerous buildup of certain gases, such as ammonia.
Other opportunities for super sniffers have emerged in disease diagnosis, homeland security, land mine, bomb, and chemical and biological warfare detection.
But of all the potential opportunities for e-tongues and e-noses, wine remains perhaps the most beguiling. "There's interesting chemistry there," neuroscientist Gelperin says. "With cake mixes the chemistry would be similarly complex, but folks wouldn't get as excited if you said you had a robot that could sample cake mixes."
Aside from the robot sommelier, a handheld Brazilian device can differentiate between cabernet sauvignons of the same vintage from two different wineries, and between different vintages from the same winery.
Andrey Legin's team at St. Petersburg State University applied one of its electronic tongues to 56 samples of Italian red wine, 20 samples of Barbera d'Asti and 36 samples of Gutturnio. The e-tongue could pick out all wine samples of the same appellation and vintage, but from different vineyards.
Australian scientists are busy studying the sensory systems of nematode worms and insect antennae to build a "new generation cybernose" for the wine industry that would indicate to winemakers the best time for picking grapes and ways to adjust the style of a wine.
And engineers continue to fine-tune the robot sommelier to get it to "distinguish more varieties of foods and wine." They're also taking steps to, well, make it more "human" by adding another sense to the robot. "A human sommelier tastes wines by using his or her total abilities, including the sense of taste, the sense of smell and the sense of texture on [the] tongue," writes Hideo Shimazu, director of NEC Japan's technology research lab and a joint leader of the winebot project, in an e-mail. "The robot lacks many senses."
But the e-tongue and e-nose technology poses some hairy challenges that can be particularly exacerbated by wine's subtle complexities. "There's more than 50 organic chemicals in wine," says Paul Keller, senior research scientist at Battelle Memorial Institute with the Pacific Northwest Laboratory, "and it also changes its odor, which we first often perceive as taste, as you're drinking it."
Not to mention that there's thousands of wine varieties and blends on the world wine market that would have to be programmed into the robot to give a full picture.
"It's not going to be the situation where you have some new vintage of wine and you want to ask the machine whether this vintage is one of the 100 best in the last 40 years or something," Gelperin says. "All those subtle distinctions are such a matter of aesthetics as well as chemistry. It's going to be a long time before any machine can do these high-order things … to have all of the degrees of judgment that a wine taster would have. The machine doesn't make judgments until you teach it the judgments you want it to make, say, to recognize variability among Bordeaux."