A Japanese engineer has created a device that can create in the language of the five basic tastes: salty, sour, sweet, bitter and umami. For each of the flavors corresponds with a particular gel substance. By default, the gel creates in the language the strong taste, but with the help of the electric potential, its intensity can be reduced and thus change the overall taste sensation like in the screen decreases the brightness of the subpixels of a specific color. To demonstrate operation of the prototype the author has wrapped it in a nori sheet, set up on sour-salty taste — according to him, it came out like sushi. Development was presented at the conference CHI 2020.
The man decided to allocate five main senses: sight, hearing, touch, smell, and taste. But the technology of reproduction of arbitrary sensory images are there mainly to sight and hearing, and partly to touch (the screens, Braille and rod displays). In the field of recreating tastes scientists conduct research and create prototypes. They mainly work by direct stimulation of receptors of a certain type. For example, there is a prototype of chopsticks, which works in two modes: simulated sour or salty taste.
Homei Miyashita (Homei Miyashita) from Meiji University have created a device to create taste sensations, which uses a different principle of operation, and is able to simultaneously combine all five basic tastes. It is a wrapped in copper foil, the tube, inside which are five more tubes of smaller diameter. Each of them is a gel substance that is responsible for a certain taste: sodium chloride for salty taste, for a sweet glycine, magnesium chloride for the bitter, citric acid for sour, and monosodium glutamate responsible for the taste umami.
Tube gels are connected to the current source through the resistors to change their resistance. When a person takes over the copper tube and placing the ends of the tubes with the gel to the tongue, forms a closed circuit. If the rheostats are creating a large resistance and the current in the circuit there is no blend of all five taste sensations, and quite intense. But the intensity of each of the flavours can be partially or almost completely reduced, reducing the resistance of a rheostat. Because of this, the electric potential forces ions from the gel move towards the cathode and the receptor language gets a lot less of them.
Changing the ratio of the resistances of the rheostats, the author was able to obtain different tastes. In one experiment, he wrapped the end of the device in the nori and set up the rheostats on the sour-salty taste. Because in addition to taste, he felt, and the smell of seaweed, he claims that she received quite a realistic simulation of the land.
In addition to the five basic tastes are recognized today, scientists continue to search for new. For example, there are hypotheses about the existence of an independent “starchy” taste, and taste fats.