title: Nanopatterning self-assembled nanoparticle superlattices by moulding microdroplets.
abstract: Highly ordered arrays of nanoparticles exhibit many properties that are not found in their disordered counterparts. However, these nanoparticle superlattices usually form in a far-from-equilibrium dewetting process, which precludes the use of conventional patterning methods owing to a lack of control over the local dewetting dynamics. Here, we report a simple yet efficient approach for patterning such superlattices that involves moulding microdroplets containing the nanoparticles and spatially regulating their dewetting process. This approach can provide rational control over the local nucleation and growth of the nanoparticle superlattices. Using DNA-capped gold nanoparticles as a model system, we have patterned nanoparticle superlattices over large areas into a number of versatile structures with high degrees of internal order, including single-particle-width corrals, single-particle-thickness microdiscs and submicrometre-sized 'supra-crystals'. Remarkably, these features could be addressed by micropatterned electrode arrays, suggesting potential applications in bottom-up nanodevices.
authors.affiliation: Department of Biological & Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Cheng
authors.forename: Nokyoung
authors.initials: N
authors.lastname: Park
authors.forename: M Todd
authors.initials: MT
authors.lastname: Walter
authors.forename: Mark R
authors.initials: MR
authors.lastname: Hartman
authors.forename: Dan
authors.initials: D
authors.lastname: Luo
mesh_terms: D003460:Crystallization; D006046:Gold / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D006046:Gold