A team of international researchers has successfully sent a chemical signal using various concentrations of rubbing alcohol (to communicate different letters) four meters across the lab using a tabletop fan. The signal, decoded by a receiver, was subsequently transformed into a text message.
“The programmable platform performs molecular communication, which mimics chemical signaling found in nature. The best known example of this is pheromone signaling used by social insects such as ants for long-range communications,” explained Olivia Solon of Wired UK. “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.”
As Solon notes, communication systems typically rely on three primary elements: the transmitter, receiver and channel. More specifically, the transmitter processes an input text message from the user, converting it into a sequence of binary bits. To conduct the experiment, the research team used an Atmel-powered Arduino Uno (ATmega328) paired with a DuroBlast spry mechanism and an LCD shield kit for text entry.
“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,” said Solon.
“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 to read the sensor data, decode it and then display a text message on a computer screen.”
The team – from Toronto’s York University and the UK’s Warwick University – selected isopropyl alcohol (rubbing alcohol) as the signaling chemical, although the system is also more than capable of operating with ethanol. According to Engineering Professor Weisi Guo from the University of Warwick, the platform could one day be used to communicate on the nanoscale “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.”