The experiments were performed with a home-made movable stage. The PET-supported sample strip was mounted between two electrodes (one movable) in a distance of 25 mm and bent in positive (upwards) direction (Figure ). To provide a better electrical contact both ends of the carbon strip were connected with silver paint. The curvature of the bending was determined by translating the shapes from photographs into x-y data using the freeware Engauge Digitizer. The curvature is defined as the inverse radius at the maximum point of bending.