3D Microfabrication Using Bulk Lithography

Abstract

Microstereolithography (MSL) has been a promising technology for fabrication of three-dimensional (3D) microstructure using layer-by-layer photopolymerization. However, this process produces 3D microstructures with a step corresponding to each layer. We propose in this paper a novel way, termed as ‘Bulk Lithography’, of generating 3D microstructures in single-pass scanning of laser beam over the photopolymer resin of unconstraint depth. In the proposed method, laser energy exposure, being one of the important parameters affecting cured depth, is varied along the line scan to enable fabrication of varying depth structure. Test structure is fabricated with proposed method to illustrate the capability of the proposed process. Lesser fabrication time and step-free 3D microfabrication in the direction perpendicular to the scan plane (z-axis) are the key features of the proposed method.