Singapore scientists devise sensor to recreate flavours on the tongue

The brainchild of Dr Nimesha Ranasinghe, who headed the project, the digital device is non-invasive and uses an electric probe to generate signals that are then transmitted through a silver electrode. 

Tip of the tongue​

Salty, sweet, sour and bitter sensations are produced by touching a probe to the tip of the tongue to produce a simulation of different tastes. By varying the levels of electrical current and the temperature of the electrode, these sensations can reproduce the tastes of different foods and drinks.

Sour, salty and bitter sensations were reported by subjects from electrical stimulation, while minty, spicy and sweet sensations were shown through thermal stimulation. 

The latter group represented minor sensations, which means that further work is needed to intensify these tastes. The responses also varied between individuals. 

Ranasinghe said the team’s work consisted of three aspects. “First, there is the study of electronic simulation and control of taste sensations that can be achieved through the digital taste interface against the properties of current and change in temperature.​

“Then there is the method of actuating taste sensations by electrical and thermal stimulation methods, either individually or in combination. And finally the aim of introducing a practical solution to implement virtual taste interactions in interactive computing systems​.”

The researcher began his project as a graduate student at the NUS Department of Electrical and Computer Engineering, and then continued the work to develop a taste-over-Internet protocol for taste messaging—a data format that facilitates the delivery of information on recreating the different tastes via the electrode.

Gaming and healthcare​

Ranasinghe, a Sri Lankan who also has a research interest in the digital simulation of smell sensations, said that the gaming industry could be an early adopter of the simulator as a new reward system based on taste sensations in a gaming environment. 

“If a gamer completes a task or level successfully, a sweet or minty dose will be rewarded​,” he said. “However, failure is delivered with a bitter taste​.”

The simulator could also have healthcare applications. For instance, diabetics could use the device to mimic sweet tastes without affecting their blood sugar levels. Cancer patients might also be able to improve their dulled sense of taste during chemotherapy with the electrode.

However, Ranasinghe said the four major tastes form only part of the flavour equation. Smell and texture play key roles too, and the researchers want to add these to the sensor in the future to provide a full tasting experience.