Solid State Ionics continues to be a rapidly developing research area. Conventionally, the field dealt with fast ion transport in solids. More recently, scope of the field has increased quite significantly. Researchers in the field of solid state ionics are now working on increasing number of systems where the predominant ionic conductivity has values comparable to liquid electrolytes. The ionic conductivity has also been found to have same order of magnitude as the electronic conductivity in semiconductors. This has brought in front of us a huge basket of opportunities for developing new technologies. The application of such materials range from environmental protection, energy conversion and storage, biofuel cells, process control, memristors, nano-electronics, polymers, etc. These niche areas of application have the capability of having major impact on present and future technologies.