Devices and methods for an expandable assembly catheter

A flexible polymer circuit strip for a catheter, the flexible polymer circuit strip comprising:

• an elongated resilient support element;
• a flexible polymer circuit connected to the elongated resilient support element, the flexible polymer circuit comprising a plurality of electrodes, each electrode defining a first conductive surface area;
• and
• a covering at least partially enclosing the elongated resilient support element, the flexible polymer circuit and the plurality of electrodes, the covering comprising a plurality of apertures over each electrode of the plurality of electrodes so that the apertures over each electrode collectively defines a second conductive surface area of approximately less than half of the first conductive surface area.

A flexible electrode device comprising:

• a flexible polymer circuit strip;
• at least two electrodes disposed on the flexible polymer circuit strip;
• a covering partially enclosing the flexible polymer circuit strip and the at least two electrodes, the covering comprising a plurality of apertures at each electrode of the at least two electrodes;
• and
• a conductive polymer disposed in each of the plurality of apertures so that an impedance measured from the electrodes is less than 13,000 ohms at 1 Hz.