(From left) Dr Ellen Do Yi-Luen (Director of Center), Dr Ranasinghe and Ms Lee Kuan-Yi (Designer at Keio-NUS CUTE Center) were members of the digital taste researchPhoto courtesy of National University of SingaporeThe brainchild of Dr Nimesha Ranasinghe, Researcher at the Center who led the project, the digital device can recreate the taste of virtual food and drinks by non-invasive electrical and thermal stimulation of the tongue. This generates signals transmitted through a silver electrode touching the tip of the tongue to produce salty, sweet, sour and bitter sensations. By combining different levels of electrical currents and varying the temperature of the electrode, simulation of the tastes can be reproduced.

From experiments, sour, salty and bitter sensations were reported from electrical stimulation, while minty, spicy and sweet sensations were reported through thermal stimulation. The latter group represented minor sensations, requiring further work to intensify the tastes. The researchers qualified that the surveys were dependent on the responses of the subjects, which varied for different individuals. 

This work has three novel aspects, said Dr Ranasinghe: the studying of the electronic simulation and control of taste sensations achievable through the Digital Taste Interface against the properties of current and change in temperature; the method of actuating taste sensations by electrical and thermal stimulation methods, either individually or in combination; and the aim of introducing a practical solution to implement virtual taste interactions in interactive computing systems.

Digital taste experimental set-up.Image courtesy of National University of SingaporeThe research team have developed taste-over-Internet protocol for taste messaging, a data format that facilitates the delivery of information on recreating the different tastes via the electrode.

Dr Ranasinghe said that a new reward system based on taste sensations in a gaming environment could be an early adopter of the simulator. As an illustration, if a gamer completes a task or level successfully, a sweet or minty dose will be rewarded. However, failure is delivered with a bitter taste. 

The simulator could have healthcare applications. For instance, diabetics could use the device for a taste of sweetness without affecting their blood sugar levels. Cancer patients may be able to improve their dulled sense of taste during chemotherapy with the electrode.

However, the four major tastes form only part of the flavour equation. Smell and texture play key roles, which the researchers want to add on for the full tasting experience.