Publisher’s Note: This paper, originally published on October 13th, was replaced with a corrected/revised version on October 30th. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.
Thin films of conjugated polymers (CPs) were explored for photothermal pattering of active materials. Due to the semiconductive nature of the CP films, CP film was heated upon NIR exposure via photothermal conversion. Various photothermal patterns were generated from the light pattern generated from POLs. The distance from the POL to the CP substrate was controlled to obtain the target light patterns with the maximum overlap or separation among the diffracted lights. From the light patterns we were able to generate micro thermal patterns to large area thermal pattern, and multiple thermal patterns. The photothermal patterns were used to pattern active layers such as cell sheets which are sensitive to heat. Using thermally responsive interfacing layer (TRI) made of collagen, cell sheets of various shapes were harvested to provide a non-invasive method of live cell sheet preparation. When photothermal CPs were coated on a thermally expandable TRI, the bilayer was folded within few sec of NIR exposure, to generate a complex 3D structure. The degree of folding and reversibility of folding were dependent on the thickness of both CP layer and TRI layer.
The conversion of photons to heat in the conductive polymer films causes local heating to increase temperature at the light exposed area. The resultant heat can be converted into other type of energy such as electrical, mechanical, or chemical energy. In particular, photothermal effect in conductive polymer layers could be used for structural changes of the 2D structures into a complex three-dimensional (3D) structure. Herein we report the preparation of photothermal conductive polymer layers (CPL) and the integration of CPLs into a 2D structured film, to optimize not only the light-to-heat but also 2D-to-3D structural conversion.