MRI-based communication for untethered intelligent medical microrobots

Miniaturization is a major challenge in fabricating medical microrobots designed to operate inside the human body. Current microrobots lack an adequate embedded communication system to transmit sensory data due to a shortage of power. In this paper, we propose a communication method, using the susceptibility effect in MRI, to overcome the size and power constraints in microrobots. The proposed method relies on a binary communication scheme in the form of a frequency alteration in the electrical current circulating along a miniature coil embedded in a microrobot. The frequency of the electrical current could be regulated by a predetermined sensory threshold input implemented in the microrobot. Such a frequency provides information on the level of sensory information gathered by the microrobot, and it is determined using single-shot EPI-GE MR images. The proposed method is independent of the microrobot’s position and orientation. Moreover, the experiments showed that MRI is sensitive enough to detect the change in magnetic field if we scaled the coil to an appropriate size for embedding into the microrobot. The proposed method could potentially apply to microrobots for monitoring and mapping specific physiological conditions within the body.