A stent delivery and apposition detecting system includes at least one electrode pair of dissimilar metals mounted on a balloon of a balloon catheter. The electrode pair forms part of an electrochemical cell, and voltage and current generated from the electrochemical cell enables the system to detect when a stent mounted on the balloon achieves proper wall apposition. As the balloon is exposed to different environments, i.e., blood or tissue having different resistances, the electric potential of the electrochemical cell changes and an alert is generated by a feedback circuit to notify a user that the electrodes are in contact with tissue of the vessel wall. In one embodiment, the feedback circuit may be powered by the electrochemical cell. Multiple sets of electrode pairs may be mounted along the circumference and length of the balloon to detect differential contact between the deployed stent and the vessel wall.