Manipulation and organization of ferromagnetic nanowires by patterned nematic liquid crystals

We introduce a method to manipulate and organize ferromagnetic nanowires using the elastic forces imposed on nanowires suspended in nematic liquid crystals via patterned variations in the nematic director. As a test case for the technique, we investigate nematic environments consisting of stripes of alternating director orientations formed by lithographically patterned substrates. Nanowires oriented by small external magnetic fields are driven by the liquid crystal to specific locations of the pattern. The observed forces on the nanowires agree with calculations based on nematic elasticity.