The application of elastic auxiliary air bag imprinting technology to the development of linear gradient micro-structure replication processes

Abstract

This study proposed an innovative imprinting process technology using an elastic auxiliary air bag imprinting mechanism, combined with poly(dimethylsiloxane) (PDMS) soft mold and UV-LED array photocuring equipment, to evenly imprint and reproduce a micro-lens mold into a gradient micro-lens structure in order to achieve linear gradient in micro-structures. The structure defined by the proposed process technology is more continuous and smoother than that of the current semi-conductor gray scale photomasking process technology. The process is simpler, faster, and less expensive and is a more effective option for satisfying the formation requirements of different structural heights. This study used pressure-sensitive film to test and discuss gradient imprint force distribution. The test results suggested that different spring constants led to tilt impressions, which caused the PDMS soft mold to contact with the substrate surface at different pressures. The color depth distribution of the pressure-sensitive film testing results indicated that the spring constant and pressure distribution were somewhat correlated. Hence, the height of structural formation can be controlled by different spring constants. Finally, SEM and surface profiler measurements suggested that different spring constants can result in different tilt degrees of the imprinting platform of air bag imprinting applications for the imprinting and reproduction of smooth, continuous micro-lens array structures of different heights. © 2012 John Wiley & Sons, Ltd.