Comparison of the radius of the helical structures under different voltages. Devices with varied thicknesses of PaC and PPy were measured. The bending radius measured for the 3 m PaC and 4 m PPy(DBS) sample at 0 V exceeds 5 mm, which surpasses our plotting scope and thus is omitted from this plot. Data are shown as mean s.d. ( n = 3). Scale bars, 1 mm ( b ); 5 mm ( c ); 5 mm, 1 mm, 50 m ( e (from left to right)); 1 cm ( f ); 2 mm ( g ).
