Three-dimensional micro-cones fabricated via two-photon photolithography

Here, we report a preparation method to fabricate 3D micro-cones with controllable morphology based on two-photon photolithography. Two-photon photolithography offers the unique ability to create arbitrarily complex 3D polymeric structures. The voxel shape of polymerization point is crucial for the topography of the micro-cone structure. Therefore, the relationship between focused voxel features of femtosecond laser and the shape of micro-cone were analyzed systematically, and a micro-cone structure with a cone height of 2 μm, cone tip of 50 nm, and a cone angle of 20° was successfully obtained in this study. In addition, 3D micro-cone structures with 10°, 20°, and 30° sharp corners have been fabricated by means of controlling the relative movement between laser focus and moving direction. Besides, the structures with a varied slope angle from 0° to 90° on the substrate surface can be obtained by controlling the post treatment process. Furthermore, a large array of 3D micro-cones has been achieved based on the proposed preparation method.