Wafer-scale multifunctional nanophotonic neural probe for brain activity mapping

Development of wafer-scale multifunctional nanophotonic neural probes for brain activity mapping

Scientists at the Max Planck Institute of Microstructure Physics Halle and the Max Planck – University of Toronto Centre for Neural Science and Technology have developed a nanophotonic neural probe for brain activity mapping. The research results have been published in the journal Lab on a Chip.

Combining light with genetic modification in the brain offers a precise optical technique to read and write to neurons with specific functions. Creating neural implants that can deliver light into the brain is important. This article reviews neural implants made using nanophotonics, a technology that offers compact photonic circuits and other devices on a microchip. These devices can perform multiple functions, including stimulating neurons with light, recording neural activity, and delivering drugs, on a single implant, helping scientists to study the brain in a more comprehensive way.

Abstract

Optical techniques, such as optogenetic stimulation and functional fluorescence imaging, have been revolutionary for neuroscience by enabling neural circuit analysis with cell-type specificity. To probe deep brain regions, implantable light sources are crucial. Silicon photonics, commonly used for data communications, shows great promise in creating implantable devices with complex optical systems in a compact form factor compatible with high volume manufacturing practices. This article reviews recent developments of wafer-scale multifunctional nanophotonic neural probes. The probes can be realized on 200 or 300 mm wafers in commercial foundries and integrate light emitters for photostimulation, microelectrodes for electrophysiological recording, and microfluidic channels for chemical delivery and sampling. By integrating active optical devices to the probes, denser emitter arrays, enhanced on-chip biosensing, and increased ease of use may be realized. Silicon photonics technology makes possible highly versatile implantable neural probes that can transform neuroscience experiments.