Nano-fabrication of polymer films using high energy heavy ion beams

Since ion beams have large mass compared with electron, they penetrate and progress lineally into polymer matrix films without large scattering. As a result, the ion beams show large energy deposition at nano-scale local area in polymer films compared with other radiation sources; the area is called 'ion track'. We explain two spatial energy distributions in the ion tracks of polymer films separately. (1) along the ion beam trajectory in the direction of film depth and (2) along the radial direction, which is perpendicular to the ion trajectory, at each point of ion trajectory. In terms of (2), as a utilization of track core located at near in trajectory centers, development of ion track separation membranes and anisotropically conducting membranes are reported. Finally, the development of electrolyte membranes for fuel cells are introduced as a utilization of penumbra located around the track core. (author)