Langmuir, Vol.17, No.9, 2866-2871, 2001
Active control of dynamic supraparticle structures in microchannels
Paramagnetic particles in microchannels form dynamic and reversible self-assembled regularly spaced structures when exposed to an external magnetic field. The magnetically induced micron-scale patterns can be formed and reformed spontaneously, thus providing an alternative to traditional microfabrication techniques for pattern creation. Under the influence of a varying magnetic field, these structures could be rotated through all axes without loss of structural form allowing dynamic micron-scale movement; without direct mechanical, electrical, or photonic interactions. The structures are not attached to the wall of the enclosure and are free to move without loss of form from both pressure-induced flow and electrokinetic effects. The dynamic supraparticle patterning can be used in an extensive variety of on-chip applications and for unique microfabrication techniques.