Molecular communications systems use the presence or absence of a selected type of molecule to digitally encode messages.
[1] The molecules are delivered into communications media such as air and water for transmission.
The technique also is not subject to the requirement of using antennas that are sized to a specific ratio of the wavelength of the signal.
Molecular communication signals can be made biocompatible and require very little energy.
[2] A Russian patent for a wireless network that uses a chemical system as the physical medium for data transmission, instead of the environment, was granted in 2018.