A high-density neural probe with novel fan-out strategy for large-scale neural recording

The complexity of the brain as the biological basis for advanced cognitive functions lies in the precise synergistic activity of an exceedingly large number of neurons. Research on high-density brain-computer interfaces drives technological and methodological innovation in neuroscience. However, a high channel count results in drawbacks such as increased weight and size due to package fan-out. Here, we develop a lightweight and stable fanout strategy to realize the package of the high-density neural probe. The neural probe with 256 channels pinned out through flip-chip patches and flexible printed circuits can be applied for large-scale chronic recordings of neurons in vivo animal experiments. The lightweight neural probe (LNP) weighs only 0.8 g, less than one-tenth of the weight of a conventional package, while the electrical performance was almost identical. Chronic animal experiments were also conducted on live mice, and action potentials of single neurons were successfully captured in multiple channels. Thus, the LNP demonstrates its lightweight and stable advantages in long-term and largescale neural activity recording, and it has a wide range of applications in neuroscience research and clinical neural engineering applications.