Bioinspired Ionic Biogels for Conformal On-Skin Wearable Bioelectronics.

Area of Science:

• Materials Science
• Biomedical Engineering
• Polymer Chemistry

Background:

• Conductive gels are crucial for on-skin wearable bioelectronics due to their flexibility and conductivity.
• Conventional gels struggle with skin's complex, dynamic surface, hindering adhesion and signal quality.

Purpose of the Study:

• To create an in situ formable conductive gel with enhanced skin adhesion and signal performance.
• To mimic sea cucumber's reversible mechanical switching for adaptive bioelectronic interfaces.

Main Methods:

• Developed a thermoresponsive ionic biogel (IBG) using gelatin, water, and an ionic liquid.
• Utilized gelatin's reversible sol-gel transition and ionic liquid for conductivity and network modulation.
• Investigated IBG's mechanical, adhesive, and electrical properties, including strain sensing and signal acquisition.

Main Results:

• The IBG can be coated in a flowable state and gels in situ on the skin.
• Optimized IBG43 demonstrated low modulus, high stretchability, and strong skin adhesion.
• Achieved stable strain sensing, reliable electrophysiological signal acquisition, and potential for self-powered sensing.

Conclusions:

• The developed IBG offers a simple and effective strategy for skin-interfaced bioelectronic materials.
• In situ gelation provides a soft, adaptive, and ion-conductive interface superior to preformed gels.
• This material advances wearable bioelectronics through improved adhesion and signal integrity.