The February 2023 issue of IEEE Spectrum is here!

Close bar

Wine Critics Watch Out: Artificial Tongues Are Getting Better

Nanosensor mimicks the sense of astringency in the human mouth when drinking wine

2 min read
Wine Critics Watch Out: Artificial Tongues Are Getting Better
Photo: Lars Kruse/Aarhus University

As it turns out we humans are not as good as we think at discerning differences in wine. While some argue considerable expertise does exist around wine tasting, others have branded that expertise junk (or should that be drunk?) science.

To overcome the junk science aspect of wine tasting, artificial tongue technologies, sometimes referred to as electronic tongues, have been advanced over the years as an objective way to discern wines based on their taste, free from the human wine critic's personal prejudices.

To further the state-of-the-art in artificial tongue technologies, researchers at the Interdisciplinary Nanoscience Centre (iNANO), at Aarhus University, have developed a nanosensor that is capable of measuring the effect of astringency in your mouth when you drink wine.

In research published in the journal ACS Nano, the Danish researchers report having developed an optical sensor based on surface plasmon resonance, which is based on the collective oscillation of electrons that occurs on the surface between a metal and a dielectric when stimulated by light.

Surface plasmon resonance (SPR) is attractive to sensor designers because the resonance wavelength is very sensitive to conditions at the interface. Because of this sensitivity, SPR has been exploited, for example, to detect biomolecules (blood glucose, for example) clinging to the conductor surface.

The design of the SPR-based nanosensor in this case involves a small plate coated with gold nanoparticles. The researchers then put some of the proteins found in human saliva on the plate. When the wine comes in contact with the plate, the gold nanoparticles act like a lens that can focus a beam of light below the diffraction limit so that it becomes possible to measure down to 20 nanometers. This makes it possible to follow the salivary proteins and see how the interaction with the wine impacts them.

In effect, the SPR-based nanosensor is using salivary proteins to measure the sensation of astringency we have when we drink wine.

Joana Guerreiro, first author of the paper, explained in a news release:

“The sensor expands our understanding of the concept of astringency. The sensation arises because of the interaction between small organic molecules in the wine and proteins in your mouth. This interaction gets the proteins to change their structure and clump together. Until now, the focus has been on the clumping together that takes place fairly late in the process. With the sensor, we’ve developed a method that mimics the binding and change in the structure of the proteins, i.e. the early part of the process. It’s a more sensitive method, and it reproduces the effect of the astringency better.”

First applications for such a nanosensor would clearly be in the production of wine, allowing winemakers to control the development of astringency from the beginning of the process. However, the researchers point out that it could be used the development of targeted medicine as well as diagnostics.

“Understanding the effect is an important prerequisite for producing better and more targeted medicine. The sensor can be used for diagnostic purposes, so it could possibly be helpful for discovering and even preventing diseases,” added Duncan Sutherland, research director for the study, in the release.

The Conversation (0)
Illustration showing an astronaut performing mechanical repairs to a satellite uses two extra mechanical arms that project from a backpack.

Extra limbs, controlled by wearable electrode patches that read and interpret neural signals from the user, could have innumerable uses, such as assisting on spacewalk missions to repair satellites.

Chris Philpot

What could you do with an extra limb? Consider a surgeon performing a delicate operation, one that needs her expertise and steady hands—all three of them. As her two biological hands manipulate surgical instruments, a third robotic limb that’s attached to her torso plays a supporting role. Or picture a construction worker who is thankful for his extra robotic hand as it braces the heavy beam he’s fastening into place with his other two hands. Imagine wearing an exoskeleton that would let you handle multiple objects simultaneously, like Spiderman’s Dr. Octopus. Or contemplate the out-there music a composer could write for a pianist who has 12 fingers to spread across the keyboard.

Such scenarios may seem like science fiction, but recent progress in robotics and neuroscience makes extra robotic limbs conceivable with today’s technology. Our research groups at Imperial College London and the University of Freiburg, in Germany, together with partners in the European project NIMA, are now working to figure out whether such augmentation can be realized in practice to extend human abilities. The main questions we’re tackling involve both neuroscience and neurotechnology: Is the human brain capable of controlling additional body parts as effectively as it controls biological parts? And if so, what neural signals can be used for this control?

Keep Reading ↓Show less
{"imageShortcodeIds":[]}