An integrated electrode structure can comprise a catheter shaft comprising a proximal end and a distal end, the catheter shaft defining a catheter shaft longitudinal axis. A flexible tip portion can be located adjacent to the distal end of the catheter shaft, the flexible tip portion comprising a flexible framework. A plurality of microelectrodes can be disposed on the flexible framework and can form a flexible array of microelectrodes adapted to conform to tissue. A plurality of conductive traces can be disposed on the flexible framework, each of the plurality of conductive traces can be electrically coupled with a respective one of the plurality of microelectrodes.