Currently, Internet and virtual reality communication is essentially audio-visual. The next important breakthrough of the Internet will be the communication and sharing of smell and taste experiences digitally. Audio-visual stimuli are frequency based, and they can be easily digitized and actuated. On the other hand, taste and smell stimuli are based on chemical molecules, therefore, they are not easy to digitize or actuate.  To solve this problem, we are required to discover new digital actuation technologies for taste and smell. The authors of this book have experimented on developing digital actuation devices for several years. This book will provide a complete overview of the importance of digitizing taste and smell, prior works, proposed technologies by the authors, other state of the art research, advantages and limitations of the proposed methods, and future applications. We expect digital taste and smell technologies will revolutionize the field of multisensory augmented reality and open up new interaction possibilities in different disciplines such as Human Computer Interaction, Communication, and Augmented and Virtual Reality.