Microchamber/nanodimple polystyrene surfaces constructing cell aggregates fabricated by thermoset mold-based hot embossing

In this study, a thermoset mold-based hot embossing technique was evaluated for the laboratory-scale replication of thermoplastic surfaces with microchamber/nanodimple (MCND) structures, which enable to construct cell aggregates. Two different types of MCND polystyrene (PS) surfaces of an indented microlens/nanodimple PS surface and an indented micropyramid/nanodimple PS one were replicated by the present hot embossing technique as a proof-of-concept study. In the hot embossing process, two different polyurethane (PU) molds were fabricated from microindented nanodimple-anodic aluminum oxide templates through the UV molding process instead of manufacturing a metal mold. In order to optimize the processing condition of the PU mold-based hot embossing process, a parametric study was carried out based on the Taguchi method. Finally, the PS MCND surfaces replicated under the optimized hot embossing condition were applied to platforms for constructing cell aggregates.