A Route to Three-Dimensional Structures in a Microfluidic Device: Stop-Flow Interference Lithography

摘要

Polymeric structures with repeating 2D and 3D motifs at the micrometer scale and below have a variety of uses. Patterned 2D structures have been shown to have myriad applications in biosensors,'11 tissue engineering, and diagnostic assay systems. The availability of more sophisticated 3D structures would enable important advances in photonics, information storage, and tissue engineering. Many techniques have been developed to fabricate complex 3D structures at the micrometer scale and below using either top-down or bottom-up approaches. Bottom-up approaches such as polymer phase separation, molecular self-assembly, or colloidal assembly are cheap and can cover large areas but face defects and limitations in the type and the geometry of structures that can be formed. While top-down methods offer precise size and shape control, the necessary point-by-point or layer-by-layer processing makes methods such as gray-scale photolithography, direct 3D writing, or two-photon lithography very time-consuming.