Hollow ring-like flexible electrode architecture enabling subcellular multi-directional neural interfacing

Implantable neural microelectrodes for recording and stimulating neural activity are critical for research in neuroscience and clinical neuroprosthetic applications. A current need exists for developing new technological solutions for obtaining highly selective and stealthy electrodes that provide reliable neural integration and maintain neuronal viability. This paper reports a novel Hollow Ring-like type electrode to sense and/or stimulate neural activity from three-dimensional neural networks. Due to its unique design, the ring electrode architecture enables easy and reliable access of the electrode to three-dimensional neural networks with reduced mechanical contact on the biological tissue, while providing improved electrical interface with cells. The Hollow Ring electrodes, particularly when coated with the conducting polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), show improved electrical properties with extremely low impedance (7 MCI mu m2) and high charge injection capabilities (15 mC/cm2), when compared to traditional planar disk-type electrodes. The ring design also serves as an optimal architecture for cell growth to create an optimal subcellular elec-trical-neural interface. In addition, we showed that neural signals recorded by the ring electrode were better resolved than recordings from a traditional disk-type electrode improving the signal-to-noise ratio (SNR) and the burst detection from 3D neuronal networks in vitro. Overall, our results suggest the great potential of the hollow ring design for developing next-generation microelectrodes for applications in neural interfaces used in physi-ological studies and neuromodulation applications.

Automated summary

This paper reports a novel Hollow Ring-like type electrode for sensing and/or stimulating neural activity from three-dimensional neural networks. The ring electrode architecture enables easy access to three-dimensional neural networks with reduced mechanical contact on the biological tissue, and provides improved electrical interface with cells. The hollow ring design shows great potential for developing next-generation microelectrodes for applications in neural interfaces.