Anti-Swelling Hydrogel Wearable Sensors: Structural Engineering, Internal Water Environment Regulation, and Motion...

Area of Science:

• Materials Science
• Wearable Technology
• Biomedical Engineering

Background:

• Wearable sensors require sustained reliability in humid environments, shifting focus from sensitivity to durability.
• Hydrogels offer biocompatibility and tunable conductivity but suffer from water absorption, causing signal drift and instability.
• Existing anti-swelling designs need enhancement beyond simple swelling ratio reduction.

Purpose of the Study:

• To review recent advancements in anti-swelling hydrogel-based wearable sensors.
• To highlight strategies for coordinated regulation of water transport, internal environment, and signal stability.
• To discuss applications and future perspectives for hydrogel sensors in wet environments.

Main Methods:

• Summarizing structural engineering strategies: network confinement, surface hydrophobicity, core-shell, and gradient structures.
• Detailing material regulation mechanisms: ionic/coordination crosslinking, nanoconfinement, zwitterionic hydration, and solvation-mediated anti-water exchange.
• Analyzing synergistic roles of these strategies in anti-swelling performance and environmental adaptability.

Main Results:

• Structural and material strategies effectively address swelling-induced issues like signal drift and instability.
• Anti-swelling hydrogels demonstrate reliable performance in applications including perspiration monitoring and underwater sensing.
• Synergistic design approaches are crucial for achieving long-term anti-swelling performance and environmental adaptability.

Conclusions:

• Anti-swelling hydrogel sensors are evolving into environmentally adaptive platforms for aqueous environments.
• Reliable sensing in wet conditions is enabled by coordinated anti-swelling regulation.
• Future work should focus on synergistic design, standardized evaluation, and scalable manufacturing for advanced applications.