Multicolored photonic barcodes from dynamic micromolding†
Barcodes have promising applications in various fields, particularly in the areas of multiplexed bioassays and anti-counterfeiting. Many researchers have focused on developing effective methods for fabricating featured barcodes. Herein, we present an innovative three-dimensional dynamic micromolding approach for generating novel photonic barcodes. The dynamic micromolding was composed of an immobilized positive microcylindrical-array substrate and complementarily negative microhole-array mold with flexible positions. As the microhole-array mold could be adjusted in the vertical direction sequentially, different kinds of structurally colored microparticles could be assembled in its vertical holes with designed sequences or arrays. By using a pregel solution to immerse the assembled microparticles, photonic barcodes with the same combinations of structurally colored sequences or arrays could be achieved by polymerizing the mixture in the mold holes. It was demonstrated that the resultant photonic barcodes exhibited large amounts of coding and thus, they were capable for use in high-throughput bioassays and anti-counterfeiting applications effectively and robustly. More importantly, by using biocompatible polymers to construct the structurally colored microparticles and photonic barcodes, they could also be applied in food and pharmaceutical areas. These remarkable properties indicate the potential of the dynamic micromolding approach for the generation of functional particles and photonic barcodes for biomedical applications.