SEM perspective and top view of devices with = 45° ( e ) twist angles. The total length of the suspended ribbon is 20 m. In all the SEM images that are shown, a carefully designed protocol has been taken to minimize the exposure of the samples to the electron beam, because we observed that the samples would deform under continuous exposure. Scale bars, 5 m ( d , e ); 500 nm ( f ); 2 m ( d , inset; e , inset).
