A navigable system for catheter based endovascular neurosurgery including: a micro-motor (3) including a piezoelectric actuator (5) mounted to a free end of a guidewire or micro-catheter (2), the piezoelectric actuator (5) including a piezoelectric element (7), and an elongate transducer (9) mounted on the piezoelectric element (7) and extending therefrom, the transducer (9) being formed from an asymmetric hollow member, and an end member (15) located at a free end of the transducer (9); wherein electrical excitation of the piezoelectric element (7) induces one or both orthogonal flexural and axial vibration modes within the transducer (9), the coupling of the induced vibration modes thereby resulting in rotation of the end member (15) with three degrees of freedom (DOF).