An integrated electrode structure comprising: a catheter shaft (107, 824) comprising a proximal end and a distal end, the catheter shaft (107, 824) defining a catheter shaft (107, 824) longitudinal axis (aa, a'a'); a flat flexible tip portion (110, 500, 540, 660, 700, 740, 780, 822) located distally with respect to the distal end of the catheter shaft (107, 824), wherein the flat flexible tip portion (110, 500, 540, 660, 700, 740, 780, 822) comprises a flat flexible framework (130, 165, 180, 130', 199, 220) that consists of a plurality of arms that extend distally from the distal end of the catheter shaft (107, 824); a plurality of microelectrodes (102, 146-1, 146-2, 146-3, 163-1, 163-2, 163-3) disposed on the flat flexible framework (130, 165, 180, 130', 199, 220) and forming a flexible planar array of microelectrodes adapted to conform to tissue; and a plurality of conductive traces (140-1, 140-2, 140-3, 162-1, 162-2, 162-3, 224-1, 224-2, 224-3, 372, 373, 388, 391, 518-1, 518-2, 518-3, 518-4, 636-1, 636-2, 636-3, 664, 750, 758-1, 758-2, 758-3) disposed on the flat flexible framework (130, 165, 180, 130', 199, 220), each of the plurality of conductive traces (140-1, 140-2, 140-3, 162-1, 162-2, 162-3, 224-1, 224-2, 224-3, 372, 373, 388, 391, 518-1, 518-2, 518-3, 518-4, 636-1, 636-2, 636-3, 664, 750, 758-1, 758-2, 758-3) electrically coupled with a respective one of the plurality of microelectrodes (102, 146-1, 146-2, 146-3, 163-1, 163-2, 163-3); a dielectric material (131, 166', 166") is disposed between each of the plurality of conductive traces (140-1, 140-2, 140-3, 162-1, 162-2, 162-3, 224-1, 224-2, 224-3, 372, 373, 388, 391, 518-1, 518-2, 518-3, 518-4, 636-1, 636-2, 636-3, 664, 750, 758-1, 758-2, 758-3) and the flexible framework (130, 165, 180, 130', 199, 220); and the dielectric material (131, 166', 166") covers an outer facing surface of each of the plurality of conductive traces (140-1, 140-2, 140-3, 162-1, 162-2, 162-3, 224-1, 224-2, 224-3, 372, 373, 388, 391, 518-1, 518-2, 518-3, 518-4, 636-1, 636-2, 636-3, 664, 750, 758-1, 758-2, 758-3). a catheter shaft (107, 824) comprising a proximal end and a distal end, the catheter shaft (107, 824) defining a catheter shaft (107, 824) longitudinal axis (aa, a'a'); a flat flexible tip portion (110, 500, 540, 660, 700, 740, 780, 822) located distally with respect to the distal end of the catheter shaft (107, 824), wherein the flat flexible tip portion (110, 500, 540, 660, 700, 740, 780, 822) comprises a flat flexible framework (130, 165, 180, 130', 199, 220) that consists of a plurality of arms that extend distally from the distal end of the catheter shaft (107, 824); a plurality of microelectrodes (102, 146-1, 146-2, 146-3, 163-1, 163-2, 163-3) disposed on the flat flexible framework (130, 165, 180, 130', 199, 220) and forming a flexible planar array of microelectrodes adapted to conform to tissue; and a plurality of conductive traces (140-1, 140-2, 140-3, 162-1, 162-2, 162-3, 224-1, 224-2, 224-3, 372, 373, 388, 391, 518-1, 518-2, 518-3, 518-4, 636-1, 636-2, 636-3, 664, 750, 758-1, 758-2, 758-3) disposed on the flat flexible framework (130, 165, 180, 130', 199, 220), each of the plurality of conductive traces (140-1, 140-2, 140-3, 162-1, 162-2, 162-3, 224-1, 224-2, 224-3, 372, 373, 388, 391, 518-1, 518-2, 518-3, 518-4, 636-1, 636-2, 636-3, 664, 750, 758-1, 758-2, 758-3) electrically coupled with a respective one of the plurality of microelectrodes (102, 146-1, 146-2, 146-3, 163-1, 163-2, 163-3); a dielectric material (131, 166', 166") is disposed between each of the plurality of conductive traces (140-1, 140-2, 140-3, 162-1, 162-2, 162-3, 224-1, 224-2, 224-3, 372, 373, 388, 391, 518-1, 518-2, 518-3, 518-4, 636-1, 636-2, 636-3, 664, 750, 758-1, 758-2, 758-3) and the flexible framework (130, 165, 180, 130', 199, 220); and the dielectric material (131, 166', 166") covers an outer facing surface of each of the plurality of conductive traces (140-1, 140-2, 140-3, 162-1, 162-2, 162-3, 224-1, 224-2, 224-3, 372, 373, 388, 391, 518-1, 518-2, 518-3, 518-4, 636-1, 636-2, 636-3, 664, 750, 758-1, 758-2, 758-3).