Soft Patch Electrode for Monitoring Human Body Signals to Help Diagnose Range of Diseases

Image: Material structure of composite film electrodes and used for body\'s signal monitoring (Photo courtesy of Wearable Electronics)

In the human body, signals generated by the movement of charged ions between cells, transmitted at the epidermal interface, reflect various biological activities. Detecting these signals can help us gain a deeper understanding of how the body's biological systems function. It also holds potential as a diagnostic tool for various diseases, including neurological disorders, heart disease, stroke, and cancer. However, the challenge in utilizing such signals lies in obtaining stable, high-quality readings from the skin. This requires electrodes that are highly conductive, flexible, and capable of functioning well across different environments. To address this, researchers have now developed a new flexible electrode that can accurately measure electrical signals from the human body.

Several factors can influence the accuracy of the body's signal measurements. For instance, the electrical resistance of the dermis and epidermis weakens the strength of the signals monitored at the epidermal interface. Additionally, relative motion between the electrodes and the skin surface can interfere with data collection, and changes in environmental conditions such as skin temperature, humidity, and sweat secretion can further affect signal quality. For wearable technology to effectively and continuously monitor epidermal signals, the materials used in the monitoring electrodes must have high conductivity, flexibility, and environmental stability.

A research team from Tianjin University (China) has been exploring ways to enhance ion transport to improve the accuracy of electrical signal monitoring. Their innovative approach demonstrates that better signals can be obtained by reducing the resistance of the film and enhancing ion transport performance. By combining two electronic-ionic conductors, the team developed a film electrode with high conductivity and high volumetric capacitance. This resulted in low electrochemical impedance with a film thickness of approximately 60 nm, as detailed in their research published in Wearable Electronics. The improved mixed conductivity allows for the accurate monitoring of electrophysiological signals, making it suitable for use in wearable electronic devices.