Thermoelectric Hydrogel Electronic Skin for Passive Multimodal Physiological Perception.

Area of Science:

• Materials Science
• Biomedical Engineering
• Wearable Technology

Background:

• Electronic skins (e-skins) are vital for physiological monitoring but often require external power and have limited sensory capabilities.
• Current e-skins face challenges with power dependency and single-functionality, hindering widespread application in health assessment.

Purpose of the Study:

• To develop a passive, multimodal electronic skin for real-time human health monitoring.
• To overcome the limitations of external power supplies and single sensory functions in current e-skin technology.

Main Methods:

• Fabrication of a thermoelectric hydrogel based on poly(vinyl alcohol)/low acyl gellan gum with a [Fe(CN)₆]^4-/3- redox couple.
• Incorporation of glycerol and Li⁺ to impart antidrying, antifreezing properties, and enhance thermopower and conductivity.
• Integration of sensing and transduction for simultaneous multimodal physiological signal acquisition.

Main Results:

• The developed hydrogel e-skin exhibits antidrying and antifreezing properties.
• Achieved a high thermopower of 2.04 mV K^-1, fast self-healing (<10 min), and high conductivity (2.56 S m^-1).
• Demonstrated real-time perception of multimodal physiological signals including body temperature, pulse rate, and sweat content without decoupling.

Conclusions:

• This passive multimodal e-skin offers a promising platform for advanced intelligent medicine and wearable electronics.
• The study provides a foundation for developing power-independent, multifunctional e-skins for continuous health monitoring.
• The synergistic coupling of sensing and transduction in the hydrogel enables efficient and integrated physiological assessment.