"O Canada", the title of the Canadian
national anthem, is the first text message to have been sent using
an inexpensive alcohol-based chemical messaging system.
A chemical signal with different levels of concentration of
rubbing alcohol (to communicate different letters) was sent four
metres across the lab with the aid of a tabletop fan. It was then
decoded by a receiver and turned back into a text message.
The programmable platform performs molecular communication,
which mimics chemical signalling found in nature. The best known
example of this is pheromone signalling used by social insects such
as ants for long-range communications. Chemical signals are also
used in inter-cellular and intra-cellular communication. This
approach to communications can be advantageous for situations when
electromagnetic wireless systems are inefficient, for example in
networks of tunnels, underwater, or at very small scales when
antenna size is restricted.
All communication systems rely on three major elements: the
transmitter, the receiver and the channel. The transmitter takes an
input text message from the user and converts it into a sequence of
The research team -- from Toronto's York University and the UK's
Warwick University -- used the Arduino Uno electronics prototyping
platform, using a 16x2 character LCD Shield Kit -- an add-on module
with six push buttons -- for text entry. The text was then
converted into a binary sequence (each letter was represented using
five bits according to the International
Telegraph Alphabet No.2, so the letter E is represented by
10000) and modulated into chemical signals (where a spray
represented 1 and no spray represented 0) using an electronic spray
mechanism called DuroBlast, which was controlled by an Arduino
The receiver had to be a sensor that could detect a chemical
signal, which can then be processed and decoded back into text.
Again, the team used the Arduino Uno micro controller to read the
sensor data, decode it and then display a text message on a
The team used isopropyl alcohol (rubbing alcohol) as the
signalling chemical, since it is widely available, volatile,
inexpensive and there are a number of cheap sensors available to
detect it. However, the receiver could also work with ethanol.
The message could be transmitted four metres using a Honeywell
desktop fan positioned behind the spray device. The team found that
a Dyson fan could create a better system response, but they were
trying to keep the costs of the system as low as possible.
The researchers tried various transmission rates, from one bit
per five seconds (a character every 25 seconds) to one bit per 2
seconds (a character every 10 seconds) across distances between one
metre and four metres. The system was deemed to be "very reliable"
at the slowest rate across all distances and very unreliable at the
"We believe we have sent the world's first text message to be
transmitted entirely with molecular communication, controlling
concentration levels of the alcohol molecules, to encode the
alphabets with single spray representing bit 1 and no spray
representing the bit 0," said doctoral candidate Nariman Farsad,
from York University in a press release.
Engineering Professor Weisi Guo from the University of Warwick
added that the system could be used to communicate on the
nanoscale, "for example in medicine where recent advances mean it's
possible to embed sensors into the organs of the body or create
miniature robots to carry out a specific task such as targeting
drugs to cancer cells."
The full study is on PLOS One