Strong, tough, anti-freezing, non-drying and sensitive ionic sensor based on fully physical cross-linked double...

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Ionic conductive double network (DN) hydrogels are crucial for wearable electronics.
• Existing hydrogels suffer from poor mechanical properties, moisture retention, and freezing resistance, limiting their application.
• Developing robust and stable ionic conductive hydrogels is essential for advanced wearable devices.

Purpose of the Study:

• To synthesize a novel ionic conductive double network (DN) hydrogel with improved mechanical and sensing properties.
• To address limitations of existing hydrogels, including poor moisture retention and freezing resistance.
• To create a high-performance hydrogel suitable for flexible sensors in wearable electronic devices.

Main Methods:

• Synthesis of a fully physically cross-linked poly (N-hydroxymethyl acrylamide)/agar/ethylene glycol (PHA/Agar/EG) hydrogel.
• Utilizing agar's sol-gel transition and interactions with PHA and NaCl via hydrogen bonds and salting-out effects.
• Incorporating ethylene glycol and NaCl to enhance mechanical properties, moisture retention, and anti-freezing capabilities.

Main Results:

• The PHA/Agar/EG hydrogel exhibited high strength, toughness, and fast self-recovery.
• The material demonstrated good fatigue resistance and self-healing properties.
• The resulting flexible sensor showed excellent long-lasting and fatigue-resistant sensing performance for monitoring human activities.

Conclusions:

• The developed PHA/Agar/EG hydrogel offers a promising strategy for fabricating high-performance flexible sensors.
• The hydrogel overcomes key limitations of traditional ionic conductive materials for wearable applications.
• This work provides a simple and effective approach for advancing smart wearable devices.