Two-DOF Micro Magnetostrictive Bending Actuator for Wobbling Motion

We propose a two-DOF micro bending actuator using Iron-Gallium alloy (Galfenol). The actuator consists of two parallel beam structures using Galfenol core, square rod of 1-mm² area and 11-mm length with ditches of 0.3-mm width. The beams in the core are wound coils and bonded to an iron end cap to construct close magnetic circuit. The orthogonal parallel beams which the push-pull elongation prebiased by permanent magnets provide bending deformation in two directions, X and Y. The advantages of the actuator are simple and rigid configuration generating high force and the identical first bending resonance frequencies of X, Y inherited form the symmetric structure. The displacement, linear round zero current, was observed varied from -15 to 15 mum at both directions. The wobbling motion with amplified displacement around resonance frequencies was also demonstrated. The actuator driven by small power supply will be applicable for cutting or drilling device for, e.g., minimally invasive surgery.