Studying the brain's recovery process after a stroke during the rehabilitation therapy (ReT) can help to provide important information leading to new rehabilitation treatment and also may help physiotherapists to tailor an optimized training plan for each patient. However, there are few devices that could be used as daily training rehabilitation tool and also can be used for studying the brain activity during ReT. Therefore, in our research, we developed an MRI compatible robot for finger rehabilitation, which possesses the required functions both. The mechanics of this robot were designed to be adjustable to different persons' finger phalanges, and also the gap between one finger to another can be easily changed. By using an ultrasonic motor as its actuator, the device has been designed to be portable, with a high torque output. It enables the client to do extension and flexion rehabilitation exercises in two degrees of freedom (DOF) for each finger. Finally, experiments have been carried out to evaluate the performance of the device.