title: Cascaded assembly of complex multiparticle patterns.
abstract: A method for the cascaded capillary assembly of different particle populations in a single assembly cycle is presented. The method addresses the increasing need for fast and simple fabrication of multicomponent arrays from colloidal micro- and nanoscale building blocks for constructing nanoelectronic, optical, and sensing devices. It is based on the use of a microfluidic device from which two independent capillary bridges extend. The menisci of the capillary bridges are pulled over a template with trapping sites that receive the colloidal particles. We describe the parameters for simultaneous, high-yield assembly from both menisci and demonstrate the applicability of the process by means of the size-selective assembly of particles of different diameters and also by the fabrication of two-component particle clusters with defined shape and composition. This approach allows the fabrication of multifunctional particle clusters having different functionalities at predetermined positions.
authors.affiliation: IBM Research - Zurich , Säumerstrasse 4, 8803 Rüschlikon, Switzerland.
authors.forename: Songbo
authors.initials: S
authors.lastname: Ni
authors.forename: Mona J K
authors.initials: MJ
authors.lastname: Klein
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Spencer
authors.forename: Heiko
authors.initials: H
authors.lastname: Wolf