Lead researcher Lee Chang-hyeok of the Brain Science Institute at the Korea Institute of Science and Technology (KIST) and the team said on the 5th that they developed a brain-computer interface (BCI) semiconductor chip that simultaneously measures the electrical and light signals of neurons. The findings were published in the international journal "Advanced Science" in June.
Existing BCIs can identify when a neural signal occurs but have limits in distinguishing which type of cell produced the signal. To precisely diagnose and treat brain disorders such as Parkinson's disease, dementia, and epilepsy, technology is needed that confirms both the timing and the type of cellular activity.
The team integrated electrodes that measure electrical signals and optical sensors that identify cell-specific responses into a single semiconductor chip. They placed 416 electrodes and 832 photodetector pixels on 13 silicon shanks the thickness of a human hair, enabling simultaneous analysis of when and where neurons responded.
The chip was fabricated by combining a standard complementary metal-oxide semiconductor (CMOS) process with a 3D-printing-based back-end process. The team said this approach maintained performance while reducing the expense to about one-hundredth that of conventional research fabrication processes. They also suggested the possibility of follow-up development using domestic semiconductor foundry and fabless infrastructure.
After implanting the chip into three brain regions of live mice, the team was able to measure both EEG changes according to anesthesia depth and the activity of neurons responding to visual stimuli. Even a week after implantation, no clear inflammation or motor dysfunction was observed.
The team sees the technology as applicable to brain disease research that requires distinguishing the location and timing of activity in specific neurons. They plan to assess its potential use in the development of electroceuticals that selectively stimulate specific cells and brain–artificial intelligence (AI) interfaces.
Lee said, "With this study, we presented a new branch called optical-semiconductor BCI and laid the groundwork to connect the strengths of Korea's world-class semiconductor industry to the BCI industry."
References
Advanced Science (2026), DOI: https://doi.org/10.1002/advs.202524260