Development of a Flexible Microneedle Array Electrode with a High Signal-to-Noise Ratio for Surface Bioelectrical...

Area of Science:

• Biomedical Engineering
• Materials Science
• Electrophysiology

Background:

• Microneedle array (MNA) electrodes are valuable for long-term, high-fidelity bioelectrical signal recording.
• Existing 3D-printed metal MNAs face challenges with surface roughness, tip sharpness, and substrate flexibility, limiting accuracy and comfort.

Purpose of the Study:

• To develop and evaluate a novel microneedle array electrode with a lightweight flexible substrate and sharp, smooth microneedles.
• To address the limitations of current 3D-printed metal MNA electrodes for improved bioelectrical signal acquisition.

Main Methods:

• Fabrication of MNA electrodes using micron-level metal 3D printing with 316L stainless steel in a single step.
• Evaluation of electrode-skin interface impedance via frequency sweep.
• Assessment of mechanical properties using porcine skin.
• Collection and analysis of bioelectrical signals.

Main Results:

• The novel MNA electrodes demonstrated contact impedance comparable to standard gold cup electrodes.
• Validated mechanical properties including flexibility and strength were achieved.
• High signal-to-noise ratio and minimal motion artifacts were recorded during bioelectrical signal acquisition.
• The fabricated electrodes showed enhanced comfort and signal quality.

Conclusions:

• The developed 3D-printed MNA electrodes overcome previous accuracy and flexibility limitations.
• These electrodes offer a promising solution for high-quality, comfortable bioelectrical signal monitoring.
• The efficient production process supports wider adoption of metal MNA electrodes in various applications.