A contact sensing catheter system includes a catheter shaft having a distal end; a flexible conductive polymer electrode located at the distal end of the shaft; and an electro-mechanical contact sensor positioned at least partially within the electrode. The sensor outputs an electrical signal in response to a mechanical force acting thereon. The sensor may be a piezoelectric sensor, a strain gauge, a fiber optic sensor, or another suitable electro-mechanical contact sensor. The electrical signal output by the sensor typically varies in response to variations in the mechanical force acting on the sensor. An output device may receive the signal output by the contact sensor and present to a user of the system an indicator of contact between the electrode and a tissue by assessing, for example, the amplitude or periodicity of the signal.