Optically-controlled neuromodulation with silicon carbide-based nanostructures

Extracellular electrical stimulation of neurons and heart cells, the standard means by which to study excitability, forms the basis for many implantable disease-treating devices including those for Parkinson's disease, depression, epilepsy, and cardiac arrhythmias. While these neural modulation devices have improved patients' quality of life, they are challenging to deploy in many animal studies due to being bulky, invasive, complex and expensive, thus limiting their use in basic neuroscience studies.

The goal of this project is to demonstrate flexible and cost-effective silicon carbide (SiC)-based nanostructures that, when triggered by light, can modulate the behavior of single neurons. These new SiC-based interfaces will enable wireless, non-genetic, multiscale, precise modulation of neurons, overcoming many of the limitations of current implantable electrodes.

This project will provide learning opportunities for students in a highly interdisciplinary area. The investigator will build on existing model programs at the University of Chicago to increase diversity in science and engineering by offering summer research opportunities to high school and undergraduate students. An international summer exchange program that allows undergraduate and graduate students to visit Israel will be continued and a special training program for outstanding high school students to compete in national competitions (e.g., Regeneron Science Talent) will be expanded.

The research and education results will be disseminated broadly through peer-reviewed publications, seminars, conference presentations, and websites.

Optogenetics has emerged as the leading modern approach for neuromodulation, but it is difficult to deploy in many animal model systems. Recently developed semiconductor and metal-based biomaterial interfaces have the potential to provide with relative ease the non-genetic and multiscale neural activities in a very broad range of animal model systems.

However, the large-scale fabrication or synthesis methods for these materials and devices are usually very complex and expensive. Additionally, there is a lack of studies of both excitatory and inhibitory neuromodulation from the same class of materials. This project addresses these two limitations through use of silicon carbide (SiC) as a material to construct neural interfaces for optically triggered non-genetic neuromodulation.

The Workflow Plan is presented as three consecutive steps: (1) innovation of synthetic methods for the large-scale silicon carbide synthesis and device fabrication, to (2) study both the excitatory and inhibitory responses using cultured neurons, and finally to (3) deployment and proof-of-concept testing in a mouse model. This project will bring together an efficient, multi-level, cross-disciplinary approach to achieve the large-scale and stable photoelectrochemical devices for random-access neuromodulation in the brain.

The proposed study will also offer a unique knowledge and skill set that can open new areas of endeavor in the semiconductor or detector industry. The silicon carbide-based membranes studied in this work can potentially yield highly efficient biomedical devices for translational studies.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.