In-process measurement of evanecent wave based nano-stereolithography using critical angle shift

Abstract

A measurement method that utilizes the critical angle shift caused by variation of resins' refractive index after polymerization has been proposed to meet the strong demand for in-process measurement on evanescent wave based nano-stereolithography. By using this measurement method, the shape of cured resins can be directly observed from the bottom of the substrate during fabrication process by detecting the reflectivity at the subcritical angle. After theoretically proving the possibility of this method, we have experimentally confirmed its feasibility by monitoring the cured resins that were still being submerged in the liquid resin.