Use of patterned magnetic films to retain and orient micro-components during fluidic assembly

Patterned magnetic thin films have for the first time been used to orient and retain micron-sized III-V elements on silicon substrates during fluidic hybrid assembly. Modeling of the forces between Ni thin films patterned on one surface of $5–6\mu \text{m}$ target areas on Si substrates predicts that the strength and fall-off characteristics of the attractive forces can be engineered to orient and securely retain only pills that are right side up. Verification of this behavior has been obtained by assembling $50\times 100\mu {\text{m}}^2$ micropills in recesses with patterns of Sm-Co rectangles.