Patent ID: 7217592

Claim:
A method for assembling and integrating microstructures (pills) onto a substrate, comprising: forming a plurality of patterned recesses on an insulating layer overlying said wafer, said recesses having transverse cross-sections and openings of specific shapes; depositing a hard magnetic layer at the bottom of each said recess; positioning a soft magnetic guide layer over said insulting layer, said guide having patterned hole shapes matching the shapes of the openings to said patterned recesses with which the holes mate; placing a collection of said pills atop said guide, said collection including members with cross-sections matching the shapes of the openings to said recesses, wherein each said pill is coated at one end with a soft magnetic layer; and applying from beneath the substrate an external continuously moving magnetic field to said collection of pills to agitate and move about the said pills, and effect a magnetic attraction between the said soft magnetic layers at the ends of said pills and the hard magnetic layer at the bottom of said recesses, said pills thereby being attracted to and falling through said similarly shaped guide holes and into the recesses and being firmly attracted to the bottoms of the recesses by the magnetic attractive forces, said pills thereby becoming attached to the hard magnetic layer at the bottom of the patterned recesses and being retained there.