Development of non-contact manipulation techniques of micro-magnetic particle by using micro electro-magnetic probe

We describe a novel manipulation technique by using localized magnetic field for manipulation of micro magnetic particles in non-contact condition. In this micro manipulation technique, soft-ferromagnetic wire that has very sharpened edge is employed as a micro electro-magnetic probe. The probe can be electro-magnetized by a solenoid wound around the probe in order to generate localized magnetic field at the probe edge. Forces of several tens nN can be generated by the electro-magnetic probe on the 1 μm diameter magnetic particle. By using the localized field, micrometer-scale magnetic particles can be selectively trapped and moved at any position on a substrate by the probe placed underneath the substrate. Chemically modified magnetic particles could be gathered at certain position on chromosome samples by using the magnetic field and adsorbed on the samples by utilizing local reaction of avidin-biotin bindings. Furthermore, the trapped micro magnetic particle was performed as a cutting tool for modification of DNA samples prepared on the substrate. The technique would be applicable in many fields such as nano and micro-scale engineering and biological manipulation.