A survey of olfactory displays: Making and delivering scents

An olfactory display is a device that generates scents with the intended component and concentration of odor material and provides it to the human olfactory organ. In combination with an odor sensing system, an olfactory display becomes a part of system that records and reproduces odors. In this article, technologies applied to modern olfactory displays are described. First, roles of olfactory displays are categorized into three functions: making scented air from the stocked form of each odor material (vaporization), switching/blending multiple kinds of scents, and delivering scented air to the human olfactory organ. Next, detailed techniques in each category are described. A variety of techniques are applied in modern olfactory displays, each of which has both advantages and limitations. Therefore, it is important to appropriately select the combination of vaporization, switching/blending, and delivery techniques, according to the purpose and characteristics of application.