Ultrastable, Omnidirectionally Stretchable, and Transparent Electrodes Based on Ag@Au Core-Sheath Nanowires with...

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Wearable electrophysiological devices require advanced transparent electrodes with stretchability, conductivity, and environmental stability.
• Existing electrodes often lack the necessary compliance and durability for dynamic skin applications.

Purpose of the Study:

• To develop environmentally robust, omnidirectionally stretchable transparent electrodes (OSTEs) using silver-gold (Ag@Au) core-sheath nanowires.
• To achieve high performance in terms of stretchability, conductivity, transparency, and environmental resilience for on-skin applications.

Main Methods:

• Fabrication of OSTEs using reusable masks for patterning on prestrained substrates, leading to self-assembled 3D wrinkled architectures.
• Utilizing salt-assisted nanowire cold-welding to enhance multidirectional stretchability and conductivity.
• Characterization of electrode performance under various strain conditions and environmental stresses.

Main Results:

• Optimized OSTEs achieved 9.24 Ω/sq with 75.0% transmittance.
• Demonstrated >10,000 cycles of 30% uniaxial strain with <55% resistance increase and maintained <1.5× initial resistance under 100% equibiaxial strain.
• Achieved thermal stability up to 250 °C and resilience in 5 wt% H2O2.

Conclusions:

• The developed Ag@Au NW OSTEs provide exceptional stretchability, stable conductivity, and environmental robustness for on-skin biosensors.
• These electrodes enable high-fidelity electrophysiological signal acquisition (EMG/ECG) with reduced motion artifacts, outperforming commercial alternatives.
• This scalable approach facilitates the development of precise wearable biosensors for dynamic health monitoring.