Study of MRI-compatible Notched Plastic Ultrasonic Stator with FEM Simulation and Holography Validation

TL;DR

This paper presents a refined MRI-compatible ultrasonic motor design using FEM simulation and holography validation, demonstrating improved rotary performance for surgical applications within MRI environments.

Contribution

It introduces a new plastic-based ultrasonic motor design validated through FEM and holography, enhancing performance for MRI-guided surgical robots.

Findings

Validated the motor design with holography techniques

Achieved improved rotary performance

Demonstrated compatibility with MRI environments

Abstract

Intra-operative image guidance using magnetic resonance imaging (MRI) can significantly enhance the precision of surgical procedures, such as deep brain tumor ablation. However, the powerful magnetic fields and limited space within an MRI scanner require the use of robotic devices to aid surgeons. Piezoelectric motors are commonly utilized to drive these robots, with piezoelectric ultrasonic motors being particularly notable. These motors consist of a piezoelectric ring stator that is bonded to a rotor through frictional coupling. When the stator is excited at specific frequencies, it generates distinctive mode shapes with surface waves that exhibit both in-plane and out-of-plane displacement, leading to the rotation of the rotor. In this study, we continue our previous work and refine the motor design and performance, we combine finite element modeling (FEM) with stroboscopic and time-averaged digital holography to validate a further plastic-based ultrasonic motor with better rotary performance.