One embodiment includes a catheter apparatus, including an elongated deflectable element including a distal end, a coupler connected to the distal end, a pusher including a distal portion, and configured to be advanced and retracted through the deflectable element, a nose connector connected to the distal portion, and including a distal receptacle having an inner surface and a distal facing opening, and an expandable assembly including flexible polymer circuit strips, each strip including electrodes disposed thereon, the strips being disposed circumferentially around the distal portion of the pusher, with first ends of the strips being connected to the coupler and second ends of the strips including respective hinges entering the distal facing opening and connected to the inner surface of the distal receptacle, the strips being configured to bow radially outward when the pusher is retracted expanding the expandable assembly from a collapsed form to an expanded form.