Mechanically Robust, Elastic, and Healable Ionogels for Highly Sensitive Ultra-Durable Ionic Skins

Area of Science:

• Materials Science
• Polymer Chemistry
• Sensor Technology

Background:

• Fabricating durable skin-mimicking sensors is difficult due to fatigue and physical damage.
• Existing sensors often lack the required longevity for real-world applications.

Purpose of the Study:

• To create ultra-durable, healable, and highly sensitive skin-mimicking sensors.
• To address the limitations of current sensor materials in terms of mechanical robustness and longevity.

Main Methods:

• Impregnating ionic liquids (ILs) into a mechanically robust poly(urea-urethane) (PU) network.
• Designing the PU network with crystallized poly(ε-caprolactone), flexible poly(ethylene glycol), and dynamic cross-links (hindered urea and hydrogen bonds).
• Characterizing the mechanical properties, elasticity, and healing capabilities of the resulting ionogels.

Main Results:

• The fabricated ionogels exhibit high mechanical strength, elasticity, and a Young's modulus similar to natural skin.
• The ionogel-based I-skins demonstrate high sensitivity to a wide range of strains (0.1-300%) and pressures (0.1-20 kPa).
• I-skins maintained reproducible electrical responses over 10,000 strain cycles and showed minimal performance degradation after 200 days in open air, with full restoration of sensing performance after thermal healing.

Conclusions:

• The developed I-skins offer exceptional long-term durability, healability, and sensitive performance, suitable for advanced skin-mimicking sensor applications.
• The combination of non-volatile ILs, dynamic PU network, and efficient healing mechanism contributes to the ultra-durability.
• This work presents a promising approach for creating next-generation wearable electronic sensors with enhanced resilience.