Dual-foot asynchronous MRI-compatible piezoelectric actuator with backward motion suppression for neurosurgical puncture

To address the need for a puncture actuator with both magnetic resonance imaging (MRI) compatibility and high positioning accuracy in MRI-guided deep brain intervention, this paper introduces a novel two-degree-of-freedom (2-DOF) asynchronous driven MRI-compatible stick-slip piezoelectric actuator with backward motion suppression. The proposed actuator features a 2-DOF piezoelectric-driven mechanism for precise needle feeding and rotation. An asynchronous dual-foot cooperative driving strategy enhances speed, load capacity, and stability, while an integrated flexure hinge effectively suppresses backward motion, improving accuracy and reliability. By alternately exciting the two driving feet, the actuator achieves continuous linear motion, optimizing the unidirectional puncture process for enhanced precision and safety. A prototype was developed and experimentally evaluated, achieving a maximum speed of 0.757 mm/s, an axial load capacity of 0.4 N, a unidirectional reciprocating error below 3.2 %, a maximum puncture force of 0.49 N, and a positioning resolution of 48 nm. Furthermore, a comparative analysis was performed to evaluate the driving characteristics of different MRI-compatible materials. The proposed actuator provides an effective MRI-compatible high-precision positioning solution for MRI-guided interventional procedures, with promising applications in neurosurgical puncture robots and targeted drug delivery systems.