Reversibly Stretchable Organohydrogel-Based Soft Electronics with Robust and Redox-Active Interfaces Enabled by...

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Hydrogel electrolytes are crucial for soft, skinlike electronic devices due to their ionic conductivity.
• Common hydrogels suffer from irreversible deformation and poor electrode contact, limiting their use in applications requiring large, repeated strains.
• Developing hydrogels with enhanced mechanical stability and interfacial properties is essential for practical, long-term soft electronics.

Purpose of the Study:

• To create multifunctional soft electronic devices with reversible stretchability and improved electrode/electrolyte interfaces.
• To investigate the use of tannic acid (TA) in polyacrylamide-based double-network organohydrogels for enhanced performance.
• To demonstrate the potential of these novel hydrogels in shape-recoverable stretchable devices and soft electronic systems.

Main Methods:

• Fabrication of polyacrylamide-based double-network organohydrogels incorporating a high concentration of tannic acid (TA).
• Characterization of the hydrogels' mechanical properties, including reversible stretchability up to 500% strain.
• Evaluation of interfacial properties, electrochemical capacitance, and long-term stability of devices under repeated stretching cycles.

Main Results:

• TA-rich organohydrogels exhibited reversible stretchability and shape recovery after significant deformation.
• Superior gel-electrode interfaces demonstrated intimate adhesion and significantly boosted electrochemical capacitance (>200 mF·cm⁻²), with a 4-fold increase observed with TA and ethylene glycol (EG).
• Soft electronic systems, including stretchable supercapacitors and microsensors, maintained electronic performance after over 1000 cycles at 200% strain without delamination.

Conclusions:

• Polyacrylamide-based double-network organohydrogels with TA offer a promising solution for mechanical and interfacial challenges in soft electronics.
• The developed hydrogels enable the creation of robust, shape-recoverable stretchable devices with enhanced performance and longevity.
• This work provides a pathway for designing advanced gel networks for next-generation soft and biocompatible electronic applications.