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Updated: May 11, 2026
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Chronic Implantation of Multiple Flexible Polymer Electrode Arrays
Published on: October 4, 2019
3D Parylene sheath neural probe for chronic recordings
1Department of Biomedical Engineering, University of Southern California, 1042 Downey Way, DRB-140, Los Angeles, CA 90089-1111, USA.
Journal of Neural Engineering
|June 1, 2013
Summary
This study introduces a novel 3D polymer neural probe coated with growth factors to improve long-term brain recordings. The flexible probe demonstrated stable electrical function and high signal quality in vivo for 28 days.
Area of Science:
- Neuroscience
- Biomaterials Engineering
- Medical Devices
Background:
- Reliable chronic neural recordings are crucial for understanding brain function and treating neurological disorders.
- Current neural probe technologies face limitations due to signal degradation from biotic and abiotic factors.
- Developing robust and long-lasting neural interfaces is a significant challenge in neuroscience research.
Purpose of the Study:
- To introduce a novel three-dimensional (3D), polymer-based neural probe with enhanced biocompatibility and recording capabilities.
- To overcome the limitations of current silicon-based and microwire neural probes for chronic implantation.
- To improve long-term signal quality and probe integration in neural tissue.
Main Methods:
- Fabrication of a 3D Parylene C sheath-based neural probe using thermal molding of a microchannel.
- Coating the probe with neurotrophic and anti-inflammatory factors encapsulated in Matrigel.
- Electrochemical characterization (cyclic voltammetry, electrochemical impedance spectroscopy) to assess electrode properties.
- Development and validation of a novel introducer tool for probe insertion.
- In vivo implantation in rat cerebral cortex for 28-day recording and immunohistochemical analysis.
Main Results:
- The 3D Parylene C probe exhibited suitable electrode properties for neural recordings (∼200 kΩ at 1 kHz).
- The probe maintained functional electrical impedance (<400 kΩ) and recorded multi-unit neuronal activity over 28 days.
- Immunohistochemistry revealed a correlation between recorded signal quality and neuronal/astrocytic density around the probe.
Conclusions:
- The developed 3D polymer neural probe technology is viable for reliable, long-term neural recordings.
- Coating with neurotrophic and anti-inflammatory factors promotes tissue integration and signal quality.
- Further optimization of probe design, including tip geometry and coating composition, can enhance performance.
