Multifurcate Assembly of Slanted Micropillars Fabricated by Superposition of Optical Vortices and Application in High‐Efficiency Trapping Microparticles

Self‐assembly induced by capillary force is abundant in nature and has been widely used in fabrication as a bottom‐up method. Here a rapid and flexible method for achieving an even number of furcate slanted micropillars by single‐exposure under a spatial phase modulated laser beam is reported, which is produced by designing a superimposed hologram with opposite topological charges to split the incident beam into several equal‐weighting sectors. These furcate micropillars with intentional spatial arrangement can be directed to capillary‐assisted self‐assembly process for generating designable hierarchical functional arrays. Due to the slanted characteristic of micropillars (8°–13°), the assembled arrays are very stable and can be used as an effective tool for trapping SiO2 particles to form honeycomb patterns with an ultrahigh trapping ratio (>90%), which can image as a microlens array. The investigation reveals that micropillars with a height of 6 µm exhibit the high trapping ratio of particles, which maintain a fine imaging performance. The fast fabrication (more than 2 orders of magnitude enhancement) of furcate slanted pillars paves an avenue for developing innovative microoptics, microfluidics and biological scaffold engineering.