Numerous aspects of communication devices, methods, and systems are described in this application. One aspect is a communication device comprising: a body comprising a distal surface compatible with skin； a tissue interface on the distal surface, the tissue interface comprising a plurality of energy generators, each energy generator being operable to output a plurality of energies in a signal direction toward the skin； and a processing unit configured to communicate with nerves associated with the skin by receiving input data, and causing the plurality of energy generators to output an energy signal in the signal direction with one or more energies of the plurality of energies.
