A Recyclable Biomimetic Flexible Sensor Based on Gallium-Based Liquid Metal for Real-Time ECG Signal Monitoring

Area of Science:

• Materials Science
• Biomedical Engineering
• Wearable Technology

Background:

• Gallium-based liquid metal (Ga-LM) offers unique properties like high conductivity, deformability, and biocompatibility.
• Stretchable electrocardiogram (ECG) sensors require high signal-to-noise ratio (SNR), low interfacial impedance, and conformability.

Purpose of the Study:

• To develop a recyclable, biomimetic flexible sensor for ECG monitoring using Ga-LM.
• To evaluate the sensor's performance, durability, recyclability, and biocompatibility for skin-contact applications.

Main Methods:

• Fabrication of nanofiber membranes via electrospinning for flexible substrates.
• Preparation of conductive inks through mechanical shearing and ultrasonication.
• Construction of a biomimetic spider-web-structured sensor by printing conductive ink onto the substrate.

Main Results:

• The sensor demonstrated excellent tensile and electrical stability, with <50% resistance change after 700 tensile cycles.
• Achieved high recyclability (95.88% Ga-LM recovery) and self-healing capability.
• Real-time ECG monitoring yielded a high SNR of 34.88 dB, comparable to traditional sensors.

Conclusions:

• The Ga-LM sensor meets core requirements for stretchable ECG monitoring, offering superior flexibility, recyclability, and durability.
• Biomimetic design and material recycling contribute to the sustainable development of flexible sensors for smart clothing.
• The sensor's biocompatibility and permeability support skin-contact wearable applications.