Development of gasbag-assisted ultraviolet-based imprinting process for replication of microstructures onto cylindrical surface

Abstract

In the conventional imprinting process, the substrate and the stamp are brought into contact and compressed directly by the plate and rigid mold. However, replicating microstructures onto a nonplanar surface is difficult due to the limited contact area and nonuniform pressure. In this study, a gasbag-assisted UV imprinting process and a flexible polydimethylsiloxane mold are employed to replicate microstructures onto a cylindrical surface, using gas to enhance the closeness of contact and uniformity of pressure during imprinting. A gas-assisted UV-based imprinting facility, which contains a gasbag, air pressure system, motor driving system, and exposure system, is designed and implemented. V-cut microstructures are imprinted on the inner surface of the cylindrical PMMA substrate. The optical performance and brightness enhancement are then verified.