Stretchable Low Impedance Electrodes for Bioelectronic Recording from Small Peripheral Nerves

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Monitoring peripheral sympathetic nerve activity is vital for understanding autonomic nervous system control in disease.
• Chronic recordings require minimally-invasive electrodes with low impedance and mechanical compliance for fragile nerves.

Purpose of the Study:

• To develop a highly stretchable, low-impedance electrode for chronic sympathetic nerve recordings in small animal models.
• To investigate the mechanical and electrical properties of stretchable electrodes for nerve interfacing.

Main Methods:

• Fabrication of stretchable electrodes using microcracked gold films coated with a stretchable conducting polymer composite (PEDOT:PSS).
• Optimization of PEDOT:PSS properties (thickness, plasticizer, deposition) for adhesion and low impedance.
• Characterization of electrode compliance under strain using Atomic Force Microscopy.
• Demonstration of functionality through chronic recordings of renal sympathetic nerve activity in rats.

Main Results:

• A highly stretchable, low-impedance electrode was successfully realized.
• Optimized PEDOT:PSS coating demonstrated compliance with microcracked gold under tensile strain.
• High-quality chronic recordings of renal sympathetic nerve activity were achieved.

Conclusions:

• The developed stretchable electrodes are suitable for long-term, high-fidelity monitoring of bioelectric signals in peripheral nerves.
• This technology advances the study of autonomic nervous system function in disease models.
• The electrode design offers a promising platform for neural interface applications.