The researchers used the Arduino Uno microcontroller board for their transmitter. For text entry, they used an Adafruit 16×2-character LCD Shield Kit that has six push buttons.

The researchers used an Arduino Uno board, an Adafruit LCD, a desk fan and a household spray bottle to transmit a short message across a tabletop, via molecular diffusion.

There's a commercial electrical sprayer (DuroBlast) that transmits the signal, and on the other side of the room there three alcohol sensors (MQ303, MQ-3, MR513) attached to an Arduino ...