"Molecular" Communication

There’s electromagnetic communication (children and pets are reportedly very sensitive to this); and pheromone communication within the same species (insects for long-range signaling, rats, humans); and now there is new information about molecular communication. This method will not replace electromagnetic waves, which transmit the bulk of data in the modern world, but there are some areas where conventional communications systems are not particularly well-adapted. These areas can include pipelines, tunnels, deep underground structures, and inside the human body. Researchers at the University of Warwick in the UK and the York University in Canada have developed the capability to transform any generic message into binary signals, which in turn is 'programmed' into evaporated alcohol molecules to demonstrate the potential of molecular communications. Dr. Weisi Guo, University of Warwick, said: "Imagine sending a detailed message using perfume―it sounds like something from a spy thriller novel, but in reality it is an incredibly simple way to communicate.” Their results are published in the open access journal PLOS ONE. 

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0082935