Whitesides Research

Techniques: Self-Assembly

Self-Assembly of Concentric Circles with MagLev

Magnetic levitation (MagLev) of diamagnetic objects (“components”) in a paramagnetic fluid, positioned in a magnetic field gradient, orders the positions of those components in three dimensions (3D).  This type of self-assembly proceeds by suspending the components, with shapes and distributions of densities designed to control their position and orientation, in an aqueous solution of MnCl2 or GdCl3, and placing this suspension between two permanent NdFeB magnets oriented with like poles facing.  The balance of magnetic and gravitational forces acting on the components—here mm-scale mirrors, lenses, filters, diffraction gratings, droplets, and soft polymeric sheets—determines their final position and orientation in 3D.  MagLev positions and aligns components without mechanical support, and eliminates solid friction and stiction.  Draining of the paramagnetic medium from a system in the magnetic field gradient stacks or positions the components into ordered structures.

Last updated on January 25, 2012

Templated Self Assembly Using Magnetic Levitation

Last updated on August 18, 2011

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