Research objectives and approaches: The objective of this research is to develop next generation 3-dimensional (3D) neural probes with combined electrical and chemical interfaces. The approach of the proposed neural probe technology is based on a flexible skin technology and a simple folding process.
Intellectual merit: The proposed technology simplifies the fabrication and assembly process of high density 3D arrays of electrodes. Furthermore, this technology enables integration of microchannels with 3D neural probes. These channels, together with electrodes, enable combined electrical and chemical stimulation, thus opening the door to many important new applications. Local drug delivery at the implantation site by microchannels would be a promising approach to reduce/suppress tissue response, one of the major obstacles for successful chronic implantation.
Broader impacts: The proposed neural probes are expected to make a significant impact on treatment of many neural disorders such as paralysis, refractory epilepsy, Parkinson?s disease, Alzheimer?s disease, blindness, deafness, and tinnitus. These probes will also help us to better understand the operation of the brain, as a result of the 3D spatial resolution and multi-modal stimulating/sensing capability. The new methods and findings will be incorporated into a Micro/Nano-Electro-Mechanical Systems course developed by Prof. Xu. A unique component of the education plan is the training of an MD/Ph.D student. This team is committed to broaden the participation of underrepresented groups, evidenced by the PI?s active role in the Research Apprentice Program for Minority Students in Detroit Public Schools.
This research aims to develop next generation multi-function 3-dimensional (3D) neural probes. The neural probe is an important tool in studying brain functions and treating many neurological disorders. Despite the progress made over the past several decades, there remains an urgent demand for further improvements and new functionality in implantable neural probes. In this proposal, we first developed 3D electrode arrays based on a silicon island structure and a simple folding procedure. Chronic neuronal recording in rats has been successfully demonstrated. 3D arrays of electrodes are highly desirable since they are able to map neural activities precisely within the 3D structure of the brain. Our new technology provides a simple and reliable method to fabricate and assemble high density 3D arrays of electrodes. In addition, the versatility of this technology allows the integration of a variety of functions within the 3D electrode arrays. We integrated micro-channels in 3D electrode arrays for chemical stimulation, or combined chemical and electrical stimulation, with high spatial resolution. We further demonstrated the integration of optical fibers with 3D electrode arrays to enable optogenetic study. A novel hybrid silicon-parylene probe to suppress tissue response has been developed as well. 4-week animal test data showed that these new probes significantly reduced tissue response. The 3D multi-function neural probes offer significant societal benefits because their new capabilities are highly desirable for better understanding the nervous system and treating many neurological disorders. For instance, the resulting probes will contribute to BRAIN Initiative (Brain Research through Advancing Innovative Neurotechnologies) President Barack Obama recently announced, due to their unprecedented 3D modulation and 3D mapping capability. Their improved chronic stability will significantly increase the therapeutic impact of neural probes. For example, with chronically stable neural probes, Brain-Machine Interfaces (BMI), which allow patients to use thoughts to directly control external prosthetic devices, will become clinically viable, improving the lives of paralyzed patients. Therefore, the proposed research could potentially benefit numerous people in the United States and globally. This award has trained two MD/PhD students and one PhD student. Five journal papers and two conference papers have been published. The research results have been presented at many conferences and incorporated into graduate/undergraduate courses Prof. Xu has developed at Wayne State University.
