Self-Closing Stretchable Cuff Electrodes for Peripheral Nerve Stimulation and Electromyographic Signal Recording

Area of Science:

• Biomedical Engineering
• Materials Science
• Neuroscience

Background:

• Reliable interfaces between cuff electrodes and complex biological tissues are crucial for physiological signal detection and stimulation.
• Existing electrodes often require complex mechanical structures for secure tissue contact, potentially causing discomfort or damage.

Purpose of the Study:

• To develop a self-closing stretchable cuff electrode that ensures reliable and non-excessive interfaces with biological tissues.
• To investigate the electrode's ability to conform to curved tissue surfaces and maintain stable contact for extended periods.

Main Methods:

• Fabrication of a stretchable cuff electrode utilizing a mechanical stress mismatch between elastic substrate layers to induce self-closing.
• Selection of substrate materials to match the elastic modulus of target tissues for minimal constraint.
• In vivo testing involving sciatic nerve stimulation and electromyographic signal monitoring in rats over one month.

Main Results:

• The proposed cuff electrode demonstrated self-closing capability upon water exposure, enabling secure attachment to tissue bundles.
• The electrode material's modulus was adaptable to match surrounding tissues, minimizing mechanical constraints.
• In vivo experiments confirmed the electrode's stable performance for both nerve stimulation and signal monitoring around the rat's extensor digitorum longus muscle for 30 days.

Conclusions:

• The self-closing stretchable cuff electrode offers a promising solution for stable and conformal interfacing with biological tissues.
• This design eliminates the need for external mechanical locking structures, simplifying application and reducing tissue irritation.
• The electrode's adaptability and sustained performance in vivo highlight its potential for various neurophysiological applications.