Modern electronics use electrical currents to transmit and process signals, but in the future this may change. The Tampere University of Technology has recently been awarded a grant for their Programmable Materials program that may lead electronics that operate without traditional electrical currents. Instead it will be the positions of electrons in different crystals affecting each other that will carry signals.
The name of the project is Photonically Addressed Zero Current Logic through Nano-Assembly of Functionalized Nanoparticles to Quantum Dot Cellular Automata, or the decidedly shorter PhotonicQCA. Its purpose is to develop programmable materials with of quantum dots that can feel the electrons in each other. Quantum dots are sometimes called artificial molecules as there are nanoscale semiconductor crystals that can be designed with specific properties. They also can be made to hold single electric charges within them, which is what PhotonicQCA takes advantage of. By moving the charge in one quantum dot it is possible to cause the movement of charge in another dot. This effect cascades to impact every quantum dot it can, but does so without the charges moving from one dot to another.
Effectively this allows for a solid state electrical transmission system on a scale denser than modern electronics have reached. As quantum dots can also be made to react to specific frequencies of light, this technology could potentially be made to operate photonically, so no electrical connections would be required for operation.