There are many interesting and open-ended questions regarding the function of the brain and the nervous system. The key signal transduction pathway lies between the electrical signals that are generated from excitable tissue and synthetic devices (e.g. computers and sensors) that can translate, interpret, and record this valuable information. However, the primary roadblock to seamless integration between the nervous system and computers is related to the lack of materials that can link these two disparate computing systems. The brain is soft, hydrated, and composed of neurons that use ions to communicate with one another. Conversely, silicon-based electronics are rigid, hermetically sealed, and use electrons to process information. This project will invent new biomimetic materials innovations that have the potential to bridge the tissue-device interface. These novel materials can match the mechanical properties of the brain and convert between ionic and electronic signals. Taken together, the improved electrode materials resulting from this project will create bioelectronics interfaces to learn more about the function of the brain. This project will also serve as an invaluable framework for training the next generation of materials scientists and electrical engineers. Students involved in this interdisciplinary project will receive training in polymer science, bioelectronics, and microelectronic device fabrication.
Technical This project will design and synthesize two classes of materials to improve the miniaturization of multielectrode arrays for use in brain-machine interfaces. Specifically, two materials innovations will be explored to increase charge injection limits and improve the chemical stealth of cortical brain-machine interfaces. First, nanoscale melanin films will increase the charge injection limit and promote electronic/ionic signal transduction. The rationale for this approach is based on the unique combination of nanoscale architecture, redox active chemistry, and biocompatibility that suggests that melanins can transduce ionic and electronic currents efficiently. Second, a class of ultra-compliant zwitterionic conducting hydrogel networks will be synthesized that will promote seamless mechanical, chemical, and electronic integration between electronically active implants and excitable tissue. Taken together, the materials innovations proposed herein will improve both the stimulation and recording of neural tissue using cortical brain-machine interfaces.