Nowadays many of the sensors used in the market take advantage of the characteristic physical behaviours of some materials to develop new devices. The piezoionic phenomenon is an effect in which applying pressure on the material generates a redistribution of ions that can be translated into a voltage and current output. This physical mechanism can be useful to describe the sensory behaviour of the skin, so its study can lead to the creation of new self-powered sensors and Smart skins as well as new robotic and prosthetic applications. This study analyses the piezoionic effect in a semi-interpenetrated polymeric network hydrogel. The impact of ionic mobility on the electrical response of the material was validated using salts with the same anion but different cation.