Dipole field controlled micro- and nanomanipulation

A novel non-contact micro- and nanomanipulation method is proposed. This method, Dipole Field Manipulation (DFM), exploits the distortion of a uniform magnetic field induced around ferromagnetic cores. While this distortion can generate strong magnetic gradients to induce pulling forces on a manipulated object, the direction of the field can be used to induce magnetic torques. This paper presents a first insight on DFM capabilities and control possibilities. We show that by varying the orientation and strength of the uniform field, DFM has the potential to achieve effective manipulation in up to six degrees of freedom. Using conventional electromagnetic coils as the uniform field source and a mobile core, gradients can reach 1-2 T/m or more in the whole manipulation workspace. Such coils provide fast directional force and torque variation capabilities, and allow an easy access to the workspace for feedback visualization and core positioning. A first concept for a 6-DOF DFM system is proposed. Results of a preliminary experiment where a particle was moved around a 0.5×1 mm rectangular path demonstrate the feasibility of the method to induce sufficient forces in any direction.