Self-Assembly of Mesoscale Obiects into Ordered Two-Dimensional Arrays

Regular arrays of topologically complex, mill imeter-scale objects were prepared by self-assembly, with the shapes of the assembling objects and the wettabil ity of their surfaces determining the structure of the arrays. The system was composed of solid objects floating at the interface between perfluorodecalin and water and interacting by lateral capil lary forces; patterning of the wettabil ity of the surfaces of the objects directs these forces. Self-assembly results from minimization of the interfacial free energy of the liquid-l iquid interface. Calculations uggest that this strategy for self-assembly can be applied to objects on a micrometer scale. Thir report tlcscribcs the directetl self-as-sembly of small objects (betu'een I ar-r. l 0 mm in lcngth) into regrr lar, tu,o-dirncnsl()n-al ilrrays. lt cxtcnds ir'leils emcrging tr ()nl molecular self-asscrnl-,1r. t, u'rLrch lrrrger,r1-'-jects ancl describes an apfr()acl-r firr the thh-r icat ion of complcx svstcrns thi l t has poten