Light-controlled electrokinetic assembly of particles near surfaces

Abstract

A method and apparatus for the manipulation of colloidal particulates and biomolecules at the interface between an insulating electrode such as silicon oxide and an electrolyte solution. Light-controlled electrokinetic assembly of particles near surfaces relies on the combination of three functional elements: the AC electric field-induced assembly of planar aggregates; the patterning of the electrolyte/silicon oxide/silicon interface to exert spatial control over the assembly process; and the real-time control of the assembly process via external illumination. The present invention provides a set of fundamental operations enabling interactive control over the creation and placement of planar arrays of several types of particles and biomolecules and the manipulation of array shape and size. The present invention enables sample preparation and handling for diagnostic assays and biochemical analysis in an array format, and the functional integration of these operations. In addition, the present invention provides a procedure for the creation of material surfaces with desired properties and for the fabrication of surface-mounted optical components.

1 . A method of making a bead array comprising: a) contacting a substrate having a planar surface with a suspension comprising populations of several differently-encoded beads having diameters of up to 10 microns, wherein each population of differently-encoded beads has a different biomolecule attached thereto; and b) applying energy to said substrate or said suspension, or both, such that the populations of differently-encoded beads form an ordered array on the planar surface and the beads are at pre-determined distances from each other. 
     
     
         2 - 17 . (canceled)