Patterned Nanoparticle Arrays Fabricated Using Liquid Film Rupture Self-Assembly

Self-assembly is an important bottom-up fabrication approachbasedon accurate manipulation of solid-air-liquid interfacesto construct microscale structures using nanoscale materials. Thisapproach plays a substantial role in the fabrication of microsensors,nanosensors, and actuators. Improving the controllability of self-assemblyto realize large-scale regular micro/nano patterns is crucial forthis approach's further development and wider applications.Herein, we propose a novel strategy for patterning nanoparticle arrayson soft substrates. This strategy is based on a unique process ofliquid film rupture self-assembly that is convenient, precise, andcost-efficient for mass manufacturing. This approach involves twokey steps. First, suspended liquid films comprising monolayer polystyrene(PS) spheres are realized via liquid-air interface self-assemblyover prepatterned microstructures. Second, these suspended liquidfilms are ruptured in a controlled manner to induce the self-assemblyof internal PS spheres around the morphological edges of the underlyingmicrostructures. This nanoparticle array patterning method is comprehensivelyinvestigated in terms of the effect of the PS sphere size, morphologicaleffect of the microstructured substrate, key factors influencing liquidfilm-rupture self-assembly, and optical transmittance of thefabricated samples. A maximum rupture rate of 95.4% was achieved withan optimized geometric and dimensional design. Compared with othernanoparticle-based self-assembly methods used to form patterned arrays,the proposed approach reduces the waste of nanoparticles substantiallybecause all nanoparticles self-assemble around the prepatterned microstructures.More nanoparticles assemble to form prepatterned arrays, which couldstrengthen the nanoparticle array network without affecting the initialfeatures of prepatterned microstructures.