New Article in Small

posted Jan 26, 2017, 12:40 AM by Shin-Hyun Kim   [ updated Jan 26, 2017, 12:40 AM ]
Ju Hyeon Kim, Kwanghwi Je, Tae Soup Shim, and Shin-Hyun Kim, "Reaction-Diffusion-Mediated Photolithography for Designing Pseudo-3D Microstructures", Small, accepted for publication (2017).

Microstructures with three-dimensional (3D) features provide advanced functionalities in many applications. We have employed reaction-diffusion process in photolithography to produce pseudo-3D microstructures in a reproducible manner. In this work, we investigate the influences of various parameters on growth behavior of polymeric structures and expand the use of the reaction-diffusion-mediated photolithography (RDP) to a wide range of structural dimensions. In addition, we study how a lens effect alters the growth behavior of microstructures in conjunction with reaction-diffusion process. For small separation between reaction sites in the array, ultraviolet (UV) exposure time is optimized along with the separation to avoid film or plateau formation. We further prove that the RDP process is highly reproducible and applicable to various photocurable resins. In a demonstrative purpose, we show the use of microdomes created by the RDP process as microlens arrays. The RDP process enables the production of pseudo-3D microstructures even with collimated UV light in the absence of complex optical setups, thereby potentially serving as a useful means to create micropatterns and particles with unique structural features.