A cylindrical ultrasonic motor for NMR sample spinning in high magnetic field

Recently, the demand for instruments that use high magnetic fields has increased in scientific and industrial fields. A high-resolution solid-state nuclear magnetic resonance (NMR) system is one such example. In a solid-state NMR, analytical samples are required to spin accurately at high speed in the high magnetic field. Ultrasonic motors have advantages in such environments. This research aims to develop a cylindrical micro ultrasonic motor for the solid-sate NMR. We fabricated a cylindrical ultrasonic motor mainly using nonmagnetic materials. The motor´s maximum diameter and the height are 11 and 47.9 mm, including the sample case. We evaluated its driving performance in a magnetic field of 7 T. In addition, we successfully obtained the ¹H-NMR signals of H₂O with the motor. The result shows the NMR ultrasonic motor is available for the sample spinning of the solid-state NMR.