LAUSR

Microcrystals with defined sizes, morphologies, and locations provide a core opportunity for applications in microelectronic devices and microoptical components. Herein, a simple method was developed to obtain microcrystals with controlled sizes and locations by capillary-assisted localized crystallization, which utilizes “discrete micropillar rings” (DMRs) to mediate the solution evaporation process. Being different from conventional hydrophilic/hydrophobic modified surfaces, DMRs can guide the movement of three-phase contact lines, confine the solution residing inside the rings with a high concentration ratio, and help to crystallize microparticles (NaCl or CaCO3) without any further surface modification. Microcrystal sizes can be tuned in a wide range (from the order of ∼μm2 to that of ∼100 μm2) by changing the geometric parameters (height, pillar interval, and diameter) of pillar arrays. This facile, scalable, and low-cost technique for generating microcrystals with controlled size and location inside the DMRs holds great promise for micro-electronic and micro-optoelectronic applications.Microcrystals with defined sizes, morphologies, and locations provide a core opportunity for applications in microelectronic devices and microoptical components. Herein, a simple method was developed to obtain microcrystals with controlled sizes and locations by capillary-assisted localized crystallization, which utilizes “discrete micropillar rings” (DMRs) to mediate the solution evaporation process. Being different from conventional hydrophilic/hydrophobic modified surfaces, DMRs can guide the movement of three-phase contact lines, confine the solution residing inside the rings with a high concentration ratio, and help to crystallize microparticles (NaCl or CaCO3) without any further surface modification. Microcrystal sizes can be tuned in a wide range (from the order of ∼μm2 to that of ∼100 μm2) by changing the geometric parameters (height, pillar interval, and diameter) of pillar arrays. This facile, scalable, and low-cost technique for generating microcrystals with controlled size and location inside...