Researchers have recently achieved a breakthrough in the development of **multimodal neural probes** using heterogeneously integrated Complementary Metal-Oxide-Semiconductor (CMOS) technology. This advancement addresses a critical gap in neuroscience by allowing scientists to capture both electrical activity and cell-type-specific dynamics simultaneously. While existing micro-electro-mechanical systems (MEMS) provide integration, they often suffer from low channel density. Conversely, traditional CMOS probes are often expensive to produce, which limits their widespread use. This new fabrication method significantly lowers production costs while enhancing probe functionality for complex brain research.

Innovative Design of Multimodal Neural Probes

The researchers implemented a simplified post-CMOS processing technique on a multi-project wafer (MPW). Essentially, this approach reduces the per-wafer cost by nearly two orders of magnitude compared to traditional methods. The process is remarkably efficient, requiring only two photolithography and three etching steps. By decoupling sensor customization from the front-end circuits, the team can define multimodal sensors—including electrodes and photodiodes—through post-processing. Consequently, this high-density architecture supports 416 electrodes and 832 photodiodes across a 13-shank probe configuration.

Furthermore, the system includes complete on-chip signal processing features like amplification and multiplexing. This integration is vital for handling the high volume of data generated during simultaneous optical and electrical recording. The team validated the system's operational feasibility through both in vitro and in vivo testing. Therefore, this architecture represents the first fully integrated active probe for high-density neural interfacing. It offers a scalable and affordable pathway for understanding complex brain mechanisms and diagnosing neurological disorders.

Frequently Asked Questions

What makes these multimodal neural probes different from existing technology?

Unlike standard MEMS-based probes, these devices utilize CMOS technology for on-chip amplification and multiplexing. This allows for a much higher channel density. Additionally, the new post-processing method makes them significantly more affordable than previous CMOS iterations.

Can these probes record different types of neural signals simultaneously?

Yes, they are specifically designed for simultaneous recording. They feature 416 electrodes for electrical activity and 832 photodiodes for optical signals, providing researchers with a comprehensive view of neural population dynamics.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or a professional recommendation. Refer to the latest local and national guidelines for clinical practice.

References

Mun JH et al. Fabrication of High-Density Multimodal Neural Probes Based on Heterogeneously Integrated CMOS. Adv Sci (Weinh). 2026 Mar 24. doi: 10.1002/advs.202524260. PMID: 41874523.

Jun JJ et al. Fully Integrated Silicon Probes for High-Density Recording of Neural Activity. Nature. 2017 Nov 9;551(7679):232-236. doi: 10.1038/nature24636.

Steinmetz NA et al. Neuropixels 2.0: A miniaturized high-density probe for stable, long-term brain recordings. Science. 2021 Apr 15;372(6539):eabf4588. doi: 10.1126/science.abf4588.