title: Magnetic Assembly and Cross-Linking of Nanoparticles for Releasable Magnetic Microstructures.
abstract: This article describes a versatile method to fabricate magnetic microstructures with complex two-dimensional geometric shapes using magnetically assembled iron oxide (Fe3O4) and cobalt ferrite (CoFe2O4) nanoparticles. Magnetic pole patterns are imprinted into magnetizable media, onto which magnetic nanoparticles are assembled from a colloidal suspension into defined shapes via the shaped magnetic field gradients. The kinetics of this assembly process are studied by evaluation of the microstructure features (e.g., line width and height) as a function of time, particle type, and volume fraction. After assembly, the iron oxide particles are cross-linked in situ and subsequently released by dissolving a sacrificial layer. The free-floating magnetic structures are shown to retain their patterned shape during manipulation with external magnetic fields.
authors.affiliation: Department of Electrical & Computer Engineering, #J. Crayton Pruitt Family Department of Biomedical Engineering, and §Department of Chemical Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Camilo
authors.initials: C
authors.lastname: Velez
authors.affiliation: Department of Electrical & Computer Engineering, #J. Crayton Pruitt Family Department of Biomedical Engineering, and §Department of Chemical Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Isaac
authors.initials: I
authors.lastname: Torres-Díaz
authors.affiliation: Department of Electrical & Computer Engineering, #J. Crayton Pruitt Family Department of Biomedical Engineering, and §Department of Chemical Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Lorena
authors.initials: L
authors.lastname: Maldonado-Camargo
authors.affiliation: Department of Electrical & Computer Engineering, #J. Crayton Pruitt Family Department of Biomedical Engineering, and §Department of Chemical Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: Carlos
authors.initials: C
authors.lastname: Rinaldi
authors.affiliation: Department of Electrical & Computer Engineering, #J. Crayton Pruitt Family Department of Biomedical Engineering, and §Department of Chemical Engineering, University of Florida , Gainesville, Florida 32611, United States.
authors.forename: David P
authors.initials: DP
authors.lastname: Arnold
keywords: ferromagnetic materials microstructures; nanoparticles; particle deposition; self-assembly