New Neurotechnology Integrates Nanophotonics and Microfluidics for Multimodal Brain Research

An international team from the Max Planck Institute for Microstructure Physics, the Krembil Brain Institute, the University of Toronto, and Advanced Micro Foundry demonstrates a silicon-photonics neurotechnology that integrates photostimulation, electrical recording, and drug delivery.

To the point:

• Three functions on one chip: 16 silicon nitride light emitters, 18 microelectrodes, and a buried microfluidic channel are monolithically integrated into a single implantable microchip.
• Validated In Vivo: The probe successfully enabled simultaneous targeted photostimulation, drug delivery, and neural activity recording in optogenetic mice. Local seizure suppression experiments highlight its potential for advancing epilepsy research.
• Scalability: Leveraging commercial silicon photonics foundry fabrication provides a pathway toward scalable manufacturing for broader distribution to neuroscience laboratories.
• Collaborative Effort: This research is the result of a collaboration between Dr. Wesley Sacher’s group at the NINT Department, MPI-MSP, and Dr. Taufik Valiante’s group at the Krembil Brain Institute in Toronto, Canada. The silicon photonics fabrication was conducted in partnership with Advanced Micro Foundry. The study was published in Microsystems & Nanoengineering.

Scientists from the Nanophotonics, Integration, and Neural Technology (NINT) Department at the Max Planck Institute for Microstructure Physics have developed an innovative silicon photonics–based neural probe that integrates optogenetic stimulation, electrophysiological recording, and microfluidic drug delivery into a single implantable device. This technology combines optical, electrical, and chemical modalities on a compact silicon nanophotonic platform by routing microfluidic channels beneath dense photonic and electrical routing layers.

In a proof of concept for epilepsy research, the team demonstrated that chemically induced seizure activity (via microfluidic drug delivery) could be locally suppressed using targeted photostimulation delivered through the probe’s nanophotonic waveguides. Meanwhile, neural activity was monitored in real time through integrated microelectrodes, highlighting the probe’s potential for closed-loop interrogation of neural circuits across optical, electrical, and chemical domains.

The ability to probe brain function simultaneously across multiple modalities is essential for advancing neuroscience, underscoring the need for implantable tools that offer multifunctional integration. Previous technologies that combined these three functions typically involved trade-offs—either limiting optical emitter channels with co-packaged fibers or polymer waveguides, or using larger, entirely fiber-based systems that displaced significant amounts of neural tissue. The new platform overcomes these challenges by monolithically integrating optical, electrical, and fluidic functionalities into a scalable silicon photonics architecture. This design not only increases the sophistication of the probe but also allows for a compact implant footprint, while scalable photonic foundry fabrication paves the way for broader distribution across neuroscience laboratories.

This study is the result of a collaboration between researchers at the Max Planck Institute for Microstructure Physics and the Krembil Brain Institute. The Max Planck – University of Toronto Centre played a crucial role as a bridge, enabling this partnership and facilitating the integration of expertise across both institutions. Silicon photonics fabrication was conducted in close collaboration with Advanced Micro Foundry. The research was published in Microsystems & Nanoengineering (Nature portfolio).