Taste is the last frontier of virtual reality. Taste is very difficult to display because it is a multi-modal sensation composed of chemical substance, haptics and sound. There has been much work on visual and auditory displays. Haptic interfaces for the hands or fingers are one of the major research fields in virtual reality. Olfactory display is not popular but flavor can be easily displayed using a vaporizer. Taste perceived by the tongue can be measured using a biological membrane sensor. It can be easily synthesized from five basic tastes. The unsolved problem in taste display is in the area of haptics. There are some projects concerned with measuring biting force. However, no haptic display for the strength of bite has previously existed
We developed a novel interface to display biting force. It is designed to fit the user’s mouth. The haptic device is composed of a 1DOF (degree-of-freedom) mechanism, employing four linkages. The configuration of the mechanical linkage takes into consideration the structure of the jaw. The shape of the linkage enables the application of force to the back teeth. Food Simulator generates force according to the captured force of real food. A film-like force sensor is used to measure the force with which real food is bitten. A force sensor is installed in the Food Simulator and the device is actuated using the force control method. The profile of the biting force of the real food is realized by force control of the device.
Food Simulator can be integrated with auditory elements and the chemical sensation of taste. The sound of biting is captured by a bone vibration microphone and is displayed via a bone vibration speaker. It is synchronized with the biting action. The chemical sensation of taste can be displayed using a micro injector installed in the end effecter. The chemical sensation is synthesized from five elements of basic taste; sweet, sour, bitter, salty and “umami” or savory. Smell is one of the chemical sensations of taste. It can be displayed using a vaporizer.