Abstract
A fundamental challenge for bioelectronics is to deliver power to miniature devices inside the body. Wires are common failure points and limit device placement. Wireless power by electromagnetic or ultrasound waves must overcome absorption by the body and impedance mismatches between air, bone, and tissue. Magnetic fields, on the other hand, suffer little absorption by the body or differences in impedance at interfaces between air, bone, and tissue. These advantages have led to magnetically-powered stimulators based on induction or magnetothermal effects. However, fundamental limitations in these power transfer technologies have prevented miniature magnetically-powered stimulators from applications in many therapies and disease models because they do not operate in clinical “high-frequency” ranges above 20 Hz. Here we show that magnetoelectric materials – applied for the first time in bioelectronics devices – enable miniature magnetically-powered neural stimulators that operate at clinically relevant high-frequencies. As an example, we show that ME neural stimulators can effectively treat the symptoms of a Parkinson’s disease model in a freely behaving rodent. We also show that ME-powered devices can be miniaturized to sizes smaller than a grain of rice while maintaining effective stimulation voltages. These results suggest that ME materials are an excellent candidate for wireless power delivery that will enable miniature neural stimulators in both clinical and research applications.
