It's the dietary equivalent of the chicken-and-egg question: Do people crave sugary foods or do they desire the payoff that comes from tasting sweetness? It has always been impossible to know, since to satisfy a sweet tooth meant popping a sweet.
But now there is an electrode that can mimic the tastes of sweet, salty, bitter, and sour. It can potentially help people with diabetes who want desserts, but should not have them; cancer patients who experience decreased sense of taste during chemotherapy; and people hooked on sugary drinks. Also, the next time someone has a great meal and wants everyone in their social media circle to know, they don't have to depend on Instagram—they can potentially email a link that mimics the deliciousness.
"Gustation is one of the fundamental and essential senses, [yet] it is almost unheard of in Internet communication, mainly due to the absence of digital controllability over the sense of taste," says Nimesha Ranasinghe, an electrical engineer and the lead researcher of the team at National University of Singapore that developed this new taste technology. "To simulate the sensation of taste digitally, we explored a new methodology which delivers and controls primary taste sensations electronically on the human tongue." This new methodology is called the Digital Taste Interface and has two main modules. The first is a control system which "formulates different properties of stimuli: magnitudes of current, frequency, and temperature," says Ranasinghe. These combine to trick the taste sensors into thinking they are experiencing food-related sensations when in fact they are only experiencing thermal changes and electrical stimulation delivered via the second module, the tongue interface—two thin, metal electrodes. "Mainly sour, salty, and bitter sensations were reported from electrical stimulation; minty, spicy, and sweet sensations were reported through thermal stimulation," says Ranasinghe.
In order to successfully communicate between the control systems and sensors requires another step. "To digitally transmit taste sensations, a new extensible markup language format, the TasteXML (TXML), is introduced to specify the format of taste messages," says Ranasinghe. And the Digital Taste Interface's virtual taste reality has many useful benefits, from medical advances to video games which can reward a winner with a sweet treat and losers with a shot of sour. "We are exploring different domains such as entertainment (taste changing drink-ware and accessories) and medical (for patients who lost the sense of taste or have a diminished sense of taste)," explains Ranasinghe. "However, our main focus is to introduce the sensation of taste as a digitally controllable media, especially to facilitate virtual and augmented reality domains."
While the team is currently in negotiations to make the technology commercially available, there are a few pressing updates in the works for the Digital Taste Interface. The first is a more appealing way to use the tongue sensors, which currently are attached while the mouth is open. It's hard to believe you are experiencing a delicious dish when you are sticking out your tongue and balancing metal slabs to it. To that end, they want an interface that can be held in the mouth, called the digital lollipop because it looks like the candy. "We believe that people won't hesitate to place these electrodes on their tongues," explains Ranasinghe about the makeover, adding that it will also allow for a deeper understanding of how electrical stimulation affects taste sensors on different parts of the tongue. In addition, they also want to incorporate smell and texture into the experience, to further extend the range of sensations.
And it just might bestow the best social media gift of all: an end to stomach-churning food shots that can make anyone lose their appetite.