Novel material development and device design for next-generation neural interface technology

Although currently available neural probes can record from and stimulate nearby neurons, they eventually fail due to decreased signal to noise ratio due to impedance increase, material degradation, and damage from the mechanical mismatch between soft brain tissue and stiff probes, among others. To address these challenges, we have been developing novel materials and device designs. To decrease interfacial impedance between the tissue and electrode, we developed conducting polymers specifically poly(3,4-ethylenedioxythiophene) or PEDOT doped with various counterions such as polystyrene sulfonate (PSS) and functionalized carbon nanotubes (CNTs). In addition, conventional metal-based electrodes perform poorly at detecting neurotransmitters. We developed multi-channel glassy carbon electrodes which are compatible with microfabrication methods. In parallel, we also spend our efforts in flexible neural probe development which can move with the micromotions of the brain, and they have been proven to elicit less adverse foreign body response compared to conventional stiff probes.

Relevant Publications

• Faul E-BA, Broussard AM, Rivera DR, Pwint MY, Wu B, Cao Q, Bailey D, Cui XT, Castagnola E. Batch Fabrication of Microelectrode Arrays with Glassy Carbon Microelectrodes and Interconnections for Neurochemical Sensing: Promises and Challenges. Micromachines. 2024; 15(2):277. https://doi.org/10.3390/mi15020277
• K. M. Woeppel, D. D. Krahe, E. M. Robbins, A. L. Vazquez, X. T. Cui, Electrically Controlled Vasodilator Delivery from PEDOT/Silica Nanoparticle Modulates Vessel Diameter in Mouse Brain. Adv. Healthcare Mater. 2024, 13, 2301221. https://doi.org/10.1002/adhm.202301221
• Elisa Castagnola, Elaine M. Robbins, Daniela D. Krahe, Bingchen Wu, May Yoon Pwint, Qun Cao, Xinyan Tracy Cui, Stable in-vivo electrochemical sensing of tonic serotonin levels using PEDOT/CNT-coated glassy carbon flexible microelectrode arrays., Biosensors and Bioelectronics, Volume 230, 2023, 115242, ISSN 0956-5663, https://doi.org/10.1016/j.bios.2023.115242.
• Castagnola E, Robbins EM, Wu B, Pwint MY, Garg R, Cohen-Karni T, Cui XT. Flexible Glassy Carbon Multielectrode Array for In Vivo Multisite Detection of Tonic and Phasic Dopamine Concentrations. Biosensors. 2022; 12(7):540. https://doi.org/10.3390/bios12070540
• T. D. Y. Kozai et al., "Chronic In Vivo Evaluation of PEDOT/CNT for Stable Neural Recordings," in IEEE Transactions on Biomedical Engineering, vol. 63, no. 1, pp. 111-119, Jan. 2016, doi: 10.1109/TBME.2015.2445713.