Methods of manufacturing optically anisotropic polymer thin films

A method comprising:

• forming a composite thin film comprising a polymer thin film and a high Poisson's ratio polymer thin film disposed directly over the polymer thin film;
• attaching a clip array to opposing edges of the composite thin film, the clip array comprising a plurality of first clips slidably disposed on a first track located proximate to a first edge of the composite thin film and a plurality of second clips slidably disposed on a second track located proximate to a second edge of the composite thin film,
• applying a positive in-plane strain to the composite thin film along a transverse direction by increasing a distance between the first clips and the second clips;
• heating the composite thin film to a temperature greater than a glass transition temperature of at least one component of the polymer thin film after applying the positive in-plane strain;
• and
• decreasing an inter-clip spacing amongst the first clips and amongst the second clips along a machine direction, wherein the high Poisson's ratio polymer thin film applies a negative in-plane strain to the polymer thin film along the machine direction to form an optically anisotropic polymer thin film.

A method comprising:

• forming a composite thin film comprising a polymer thin film and a high Poisson's ratio polymer thin film disposed directly over the polymer thin film;
• attaching a clip array to opposing edges of the composite thin film, the clip array comprising a plurality of first clips slidably disposed on a first track located proximate to a first edge of the composite thin film and a plurality of second clips slidably disposed on a second track located proximate to a second edge of the composite thin film;
• applying a positive in-plane strain to the composite thin film along a transverse direction by increasing a distance between the first clips and the second clips;
• decreasing an inter-clip spacing amongst the first clips and amongst the second clips along a machine direction, wherein the high Poisson's ratio polymer thin film applies a negative in-plane strain to the polymer thin film along the machine direction to form an optically anisotropic polymer thin film;
• and
• separating the high Poisson's ratio polymer thin film from the optically anisotropic polymer thin film.