title: Bending of nanoscale filament assemblies by elastocapillary densification.
abstract: We report a mechanism by which nanoscale filaments self-assemble into asymmetric aggregates by elastocapillary action. Specifically, capillary rise of liquid into an asymmetric pattern of vertically aligned filaments causes the filaments to deflect laterally during elastocapillary densification. We quantitatively show that the lateral deflection can be controlled precisely by the pattern shape and the coupling strength among the filaments. We exploit this mechanism to fabricate asymmetric micropillars and multidirectional bridges of densely packed carbon nanotubes. Analogous behavior occurs as biological filaments interact with liquids, and these findings enable scalable fabrication of anisotropic filament assemblies for manipulating surface interactions between solids and liquids.
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Zhouzhou
authors.initials: Z
authors.lastname: Zhao
authors.forename: Sameh H
authors.initials: SH
authors.lastname: Tawfick
authors.forename: Sei Jin
authors.initials: SJ
authors.lastname: Park
authors.forename: Michael
authors.initials: M
authors.lastname: De Volder
authors.forename: A John
authors.initials: AJ
authors.lastname: Hart
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
mesh_terms: D004548:Elasticity; D055595:Mechanical Phenomena; D008962:Models, Theoretical; D049329:Nanostructures / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry; D011312:Pressure; D015203:Reproducibility of Results
chemical_list: D037742:Nanotubes, Carbon