Stretchable gold nanowire-based cuff electrodes for low-voltage peripheral nerve stimulation

Area of Science:

• Bioelectronic Medicine
• Biomaterials Engineering
• Neuroscience

Background:

• Electrical stimulation of the peripheral nervous system (PNS) offers therapeutic potential for various conditions, including nerve injury.
• A key challenge in PNS electrode design is the mechanical mismatch between the nerve and the device, causing poor contact and inefficient stimulation.
• Existing soft and stretchable electrodes often exhibit limited performance or use non-standard materials.

Purpose of the Study:

• To develop a high-performance, soft, and stretchable cuff electrode using inert materials for low-voltage peripheral nerve stimulation.
• To address the limitations of current electrodes in terms of mechanical compatibility and stimulation efficiency.

Main Methods:

• Fabrication of 50 µm thick stretchable cuff electrodes using silicone rubber, gold nanowire conductors, and platinum-coated nanowire electrodes.
• Characterization of electrode durability under 50% strain cycling and one million stimulation pulses.
• In vivo evaluation of stimulation capability in a rat sciatic nerve model, measuring electromyography responses.

Main Results:

• The developed stretchable cuff electrodes demonstrated excellent stability during extensive strain cycling and stimulation.
• Saturated, homogeneous sciatic nerve stimulation was achieved at a low voltage of 200 mV.
• High performance attributed to excellent electrode conformability, low conductor resistance (0.3 Ohm sq⁻¹), and low electrode impedance.

Conclusions:

• The novel stretchable cuff electrode integrates superior mechanical properties with effective, stable electrode performance using inert materials.
• This electrode is well-suited for low-power applications in bioelectronic medicine, particularly for peripheral nerve stimulation.
• The findings pave the way for improved therapeutic strategies in nerve repair and neuromodulation.