Protein-Based Electronic Skin Akin to Biological Tissues

Area of Science:

• Materials Science
• Biomedical Engineering
• Nanotechnology

Background:

• Human skin's role in sensory transduction and communication with the brain.
• Limitations of current electronic skin (E-skin) devices, including poor biocompatibility, biofunctionality, and permeability.
• Need for advanced materials that mimic natural skin properties for effective E-skin applications.

Purpose of the Study:

• To engineer highly flexible, stretchable, and conformal E-skins with improved biocompatibility and molecule permeability.
• To integrate metallic nanowire (NW) networks with silk protein hydrogels for enhanced performance and stability.
• To enable E-skin devices capable of sensing diverse physiological and environmental signals.

Main Methods:

• Fabrication of E-skin by combining a metallic nanowire (NW) network with a silk protein hydrogel.
• Utilizing Ca2+ ions and glycerol to enhance the stretchability and stability of silk protein hydrogels under hydration.
• Characterization of NW electrode performance under large deformations and hydration, and assessment of hydrogel permeability.

Main Results:

• Developed highly flexible, stretchable, conformal, and skin-adhering E-skins.
• Achieved stable electrode operation under large deformations and hydration.
• Demonstrated E-skin's capability for sensing strain, electrochemical, and electrophysiological signals due to hydrogel window facilitating molecular exchange.

Conclusions:

• The novel silk protein-based E-skin offers superior flexibility, stretchability, and biocompatibility compared to conventional polymer-based devices.
• The integrated NW network and silk hydrogel system provides a robust platform for advanced biosensing applications.
• This E-skin technology holds significant potential for seamless human-machine interfaces and advanced physiological monitoring.