Introduction

It is generally accepted that the sensory world of most humans is built up mainly from visual and auditory impressions, and that other senses, such as smell, have smaller impact. Nevertheless, it seems that the sense of smell is often underestimated, and its impact actually may be overwhelming, directly influencing ancient, primitive, brain paths. Interestingly, humanity has already recognized this a long time ago, perhaps subconsciously , with scents already playing a significant role in ancient religious rituals.

Many applications require some means of controlling the odor world. A repertoire of methods in fragrance production and synthesis has been developed, aiming at safe, cheap, and reproducible odor fabrication techniques. Still, hard labor is required for each individual odor fabrication process, involving tedious, expensive, time consuming research. In the last few decades, there have been efforts to integrate odors into the rapidly evolving world of modern communication. Adding smells to a personal computer, a video, a television set, or a mobile phone, would give rise to a vast number of possible applications, in the fields of commerce, marketing, computer games, and many others. However, available odor technologies seem to be incapable of supporting such applications, making it necessary to develop novel technologies. Today, only simple odor manipulations can be carried out. For example, scented cards are often inserted as sales promoters in magazines, dispensing a fragrance when scratched. Similar “scratch and sniff" devices sometimes accompany movies or home television. Some recent model of mobile phones contains small capsules, emitting pre-determined scents when certain people call. There have even been attempts to introduce odors by means of air conditioning systems in movie theaters and in the workplace. Still, none of the above comes close to the technological advances in vision and audition. One of the most salient expressions of this gap is in modern multimedia. Pictures and sound are routinely transmitted and exhibited on television, video or the personal computer. This has not happened yet with odors.