Soft conducting polymers working in aqueous solutions were the bases for the development of electrochemomechanical actuators. The actuation of those devices involves: polymers, counterions, water, electric pulses and volume variations by water and counterions interchange with the polymer. Those processes mimic similar ones occurring in natural muscles, being the origin of their nomination as artificial muscles. The driving force for the stimulation of the processes is electric pulses generating electrochemical reactions. This fact gives a unique possibility to these actuators: they can work, simultaneously, as an actuator driven by a constant current and as a sensor of any chemical, mechanical or physical variable influencing the electrochemical reaction. We will show here how, using only two connecting wires, those devices work, simultaneously, as both, actuators and as a mechanical and a chemical sensor.