Recent progress in brain signal monitoring and neuromodulation technologies

Brain science research is an important challenge in today's natural sciences. Over the past century, the main progress in brain science research was to understand the basic principles of neural information transmission and processing in neural networks. In recent years, with the development of new technologies in molecular biology and physiology, the molecular and cellular mechanisms of gene expression, neuronal differentiation, and neural connection formation during brain development have been revealed. Some neural circuits and electrical activity patterns related to brain functions have also been illuminated. Scientists are dedicated to conducting deeper research into brain science by establishing direct connections to the brain. The emergence of neural electrode technology allows to investigate and modulate large groups of neurons in different brain regions. Brain-computer interface (BCI) is a device that allows a direct communication path between the brain and external devices without relying on a conventional route (peripheral nerves, muscles, etc.). Brain neural signal monitoring and modulation technology is an important means of establishing information connection pathways between the brain and external devices, which plays an important role in signal acquisition and signal feedback in brain-computer interfaces. It is a cross-disciplinary technology, involving neuroscience, computer science, communication and information processing technology, artificial intelligence technology, etc. It shows broad development and application prospects, including disease diagnosis and treatment, science and education, military, education, entertainment, autonomous driving, industrial control, etc. To obtain higher spatiotemporal resolution and signal-to-noise ratio, it is necessary to promote invasive brain neural signal monitoring and modulation technology. Invasive electrodes usually face some issues such as biocompatibility, signal stability, and long-term durability, which inhibit their widespread applications in the real world. This paper briefly introduces the basic principles of brain neural signal monitoring and modulation technology, explains the research status of invasive brain neural signal monitoring and modulation technology from the perspective of key technologies such as signal acquisition, neuromodulation modalities, electrode preparation, and electrode structure design, and discusses challenges. Finally, we look forward to the application prospects of invasive brain neural signal monitoring and modulation technology in cutting-edge fields such as brain-computer interfaces.