Electrode materials for brain–machine interface: A review

Abstract Brain–machine interface (BMI) is a device that translates neuronal information into commands, which is capable of controlling external software or hardware, such as a computer or robotic arm. In consequence, the electrodes with desirable electrical and mechanical properties for direct interacting between neural tissues and machines serves as the crucial and critical part of BMI technology. Nowadays, the development of material science provides many advanced electrodes for neural stimulating and recording. Particularly, the widespread applications of nanotechnologies have innovatively introduced biocompatible electrode that can have similar characteristics with neural tissue. This paper reviews the existing problems and discusses the latest development of electrode materials for BMI, including conducting polymers, silicon, carbon nanowires, graphene, and hybrid organic–inorganic nanomaterials. In addition, we will inspect at the technical and scientific challenges in the development of neural electrode for a broad application of BMI with focus on the biocompatibility, mechanical mismatch, and electrical performance of electrode materials.