Self-folding graphene cuff electrodes for peripheral nerve stimulation

Peripheral nerve stimulation using implantable electrodes has gained significant attention as a potential treatment for drug-resistant neurological disorders. Developing deformable thin-film electrode devices is essential to minimize damage when interfacing with fine nerve fibers. Here, we demonstrate a self-folding graphene-based thin-film electrode for peripheral nerve stimulation. The self-folding films were patterned with holes and slits to control the folding direction, enabling the thin film to wrap around nerve fibers while allowing current application through the slits. Approximately 80% of the films were confirmed to fold in the intended direction in accordance with the hole formations. Furthermore, the introduction of slits reduced the impedance between the graphene and the electrolyte. When applied to the sciatic nerve of a rat, the electrodes induced leg movement upon electrical pulse stimulation at 1 Hz, indicating successful excitation of motor neurons and subsequent muscle contraction. This electrode design will enhance the versatility of nerve stimulation by targeting finer nerve fibers, thereby contributing to advancements in neural stimulation therapies.