A Hydrogel-Based Microfluidic Nerve Cuff for Neuromodulation of Peripheral Nerves.

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Implantable neuromodulation devices use metal electrodes that can damage nerves with prolonged electrical stimulation.
• Current devices are limited in delivering long-duration pulses or direct current (DC) due to electrochemical processes and toxic byproduct release.
• Hydrogel coatings enhance electrode charge injection but a more robust interface is needed.

Purpose of the Study:

• To develop a novel silicone-based nerve cuff lead with a hydrogel microfluidic conduit for improved neural interfacing.
• To create a flexible, soft interconnection that increases spatial separation between electrodes and nerves.
• To enable safe, long-duration stimulation and recording, including reversible direct current (DC) nerve block.

Main Methods:

• A silicone-based nerve cuff lead with an integrated hydrogel microfluidic conduit was fabricated using a digital cutter and molding process.
• The device was tested in an in vivo rat model for sciatic nerve stimulation and recording.
• Direct current (DC) was delivered through the lead to assess nerve block capabilities.

Main Results:

• The hydrogel microfluidic nerve cuff demonstrated comparable performance to traditional metal electrodes for nerve stimulation and recording.
• Reversible nerve block was successfully induced using acute DC delivery through the novel cuff.
• The fabrication process was simplified, utilizing consumer-grade equipment.

Conclusions:

• The developed hydrogel microfluidic nerve cuff electrode offers a safe and effective alternative for peripheral neuromodulation.
• This device overcomes limitations of traditional electrodes, allowing for long-duration stimulation and DC delivery.
• Its accessible fabrication method makes it a valuable tool for neuromodulation research.