Gecko's Toes-Inspired High-Adhesive and Self-Healable Elastomer in Marine Conditions: Humidity-Triggered Crosslinking and Damage Sensing

Abstract

The development of smart materials capable of underwater self-healing, mechanical robustness and damage-healing sensing attributes holds great promise for applications in marine energy exploitation. However, achieving excellent humidity self-healing, superior adhesion, and effective damage sensing and monitoring properties simultaneously is challenging because the disturbance of water molecules to dynamic-interaction reconstruction. Herein, inspired by gecko's toes, an ultra-robust environmental adaptative self-healing supramolecular elastomer is designed by molecular engineering of water-insensitive dynamic network, which possesses efficient self-healing and visual damage sensing capabilities. Through coupling design of hierarchical hydrogen bonds, humidity-tolerant catechol coordination and photothermal sensitivity moiety, the elastomer achieves high Young's modulus (157.72 MPa) and superior self-healing efficiency (84.68%). Moreover, the autonomous association between catechol groups and steel surface endows the resultant elastomer with outstanding adhesion force (12.82 MPa) in humid conditions. Furthermore, this elastomer can be fabricated as a patch covered on steel substrates. The damage-healing dynamics and interfacial failure characteristics are visually demonstrated by the reversible fracture and reconstruction of iron-catechol coordination bonds, realizing real-time damage sensing and monitoring. This study provides a novel strategy for the design of next-generation smart protective materials in harsh marine environment, and expected for ensuring the stable operation of marine energy mining equipment.

Keywords

damage sensing / dynamic healing monitoring / metal-ligand coordination bonds / smart coating / wet adhesion

References

[1] Z. Sun, Y. Cheng, B. Wan, et al., “Constructing Mechanically Robust, Efficient Self-Healing, High-Energy, and Recyclable Energetic Composites by Hybrid Dynamic Lock Strategy,” SmartMat 5, no. 5 (2024): e1277.

[2] W. Liu, X. Wang, L. Yang, et al., “Swing Origami-Structure-Based Triboelectric Nanogenerator for Harvesting Blue Energy Toward Marine Environmental Applications,” Advanced Science 11, no. 23 (2024): 2401578.

[3] T. Lu, P. Sherman, X. Chen, S. Chen, X. Lu, and M. McElroy, “India's Potential for Integrating Solar and On- and Offshore Wind Power Into Its Energy System,” Nature Communications 11, no. 1 (2020): 4750.

[4] M. Zhang, Y. Liang, M. Feng, et al., “Corrosion Behaviour of Aluminide Coatings on Ti-Based Alloy in the Marine Environment at High Temperature,” Corrosion Science 209 (2022): 110750.

[5] Q. Ding, Z. Zhou, H. Wang, et al., “Self-Healable, Recyclable, Ultrastretchable, and High-Performance NO₂ Sensors Based on an Organohydrogel for Room and Sub-Zero Temperature and Wireless Operation,” SmartMat 4, no. 1 (2023): e1141.

[6] Q. Ding, H. Wang, Z. Zhou, et al., “Stretchable, Self-Healable, and Breathable Biomimetic Iontronics With Superior Humidity-Sensing Performance for Wireless Respiration Monitoring,” SmartMat 4, no. 2 (2023): e1147.

[7] X. Yu, C. Li, C. Gao, X. Zhang, G. Zhang, and D. Zhang, “Incorporation of Hydrogen-Bonding Units Into Polymeric Semiconductors Toward Boosting Charge Mobility, Intrinsic Stretchability, and Self-Healing Ability,” SmartMat 2, no. 3 (2021): 347–366.

[8] Q. Zhang, F. Chen, X. Shen, et al., “Self-Healing Metallacycle-Cored Supramolecular Polymers Based on a Metal-Salen Complex Constructed by Orthogonal Metal Coordination and Host–Guest Interaction With Amino Acid Sensing,” ACS Macro Letters 10, no. 7 (2021): 873–879.

[9] H. Park, T. Kang, H. Kim, J.-C. Kim, Z. Bao, and J. Kang, “Toughening Self-Healing Elastomer Crosslinked by Metal-Ligand Coordination Through Mixed Counter Anion Dynamics,” Nature Communications 14, no. 1 (2023): 5026.

[10] M. Zhu, J. Li, J. Yu, Z. Li, and B. Ding, “Superstable and Intrinsically Self-Healing Fibrous Membrane With Bionic Confined Protective Structure for Breathable Electronic Skin,” Angewandte Chemie International Edition 61, no. 22 (2022): e202200226.

[11] N. N. Xia, X. M. Xiong, J. Wang, M. Z. Rong, and M. Q. Zhang, “A Seawater Triggered Dynamic Coordinate Bond and Its Application for Underwater Self-Healing and Reclaiming of Lipophilic Polymer,” Chemical Science 7, no. 4 (2016): 2736–2742.

[12] Y. Cao, H. Wu, S. I. Allec, B. M. Wong, D.-S. Nguyen, and C. Wang, “A Highly Stretchy, Transparent Elastomer With the Capability to Automatically Self-Heal Underwater,” Advanced Materials 30, no. 49 (2018): 1804602.

[13] C.-L. He, F.-C. Liang, L. Veeramuthu, et al., “Super Tough and Spontaneous Water-Assisted Autonomous Self-Healing Elastomer for Underwater Wearable Electronics,” Advanced Science 8, no. 21 (2021): 2102275.

[14] D. Davydovich and M. W. Urban, “Water Accelerated Self-Healing of Hydrophobic Copolymers,” Nature Communications 11, no. 1 (2020): 5743.

[15] Z. Kong, E. K. Boahen, D. J. Kim, et al., “Ultrafast Underwater Self-Healing Piezo-Ionic Elastomer via Dynamic Hydrophobic-Hydrolytic Domains,” Nature Communications 15, no. 1 (2024): 2129.

[16] Y. Fujisawa, A. Asano, Y. Itoh, and T. Aida, “Mechanically Robust, Self-Healable Polymers Usable Under High Humidity: Humidity-Tolerant Noncovalent Cross-Linking Strategy,” Journal of the American Chemical Society 143, no. 37 (2021): 15279–15285.

[17] K. Kikkawa, Y. Sumiya, K. Okazawa, K. Yoshizawa, Y. Itoh, and T. Aida, “Thiourea as a ‘Polar Hydrophobic’ Hydrogen-Bonding Motif: Application to Highly Durable all-Underwater Adhesion,” Journal of the American Chemical Society 146, no. 30 (2024): 21168–21175.

[18] Y. Tian, Z. Wang, S. Cao, et al., “Connective Tissue Inspired Elastomer-Based Hydrogel for Artificial Skin via Radiation-Indued Penetrating Polymerization,” Nature Communications 15, no. 1 (2024): 636.

[19] D. Yan, J. Liu, Z. Zhang, et al., “Dual-Functional Graphene Oxide-Based Nanomaterial for Enhancing the Passive and Active Corrosion Protection of Epoxy Coating,” Composites Part B: Engineering 222 (2021): 109075.

[20] H. Wu, Z. Zhu, N. Gao, L. Ma, J. Li, and F. Liu, “The Biomimetic Design Provides Efficient Self-Healing of Ultrahigh-Tough and Damage-Warning Bio-Based Elastomer for Protective Clothing of Metals,” Nano Research 16, no. 7 (2023): 10587–10596.

[21] Y. Zhao, C.-Y. Lo, L. Ruan, et al., “Somatosensory Actuator Based on Stretchable Conductive Photothermally Responsive Hydrogel,” Science Robotics 6, no. 53 (2021): eabd5483.

[22] O. A. Kuznetsov, S. Mohanty, E. Pigos, G. Chen, W. Cai, and A. R. Harutyunyan, “High Energy Density Flexible and Ecofriendly Lithium-Ion Smart Battery,” Energy Storage Materials 54 (2023): 266–275.

[23] H.-S. Lee, H. G. Kim, J.-S. Ryou, Y. Kim, and B.-H. Woo, “Corrosion State Assessment of the Rebar: Experimental Investigation by Ambient Temperature and Relative Humidity,” Construction and Building Materials 408 (2023): 133598.

[24] W. Dong, Y. Guo, Z. Sun, Z. Tao, and W. Li, “Development of Piezoresistive Cement-Based Sensor Using Recycled Waste Glass Cullets Coated With Carbon Nanotubes,” Journal of Cleaner Production 314 (2021): 127968.

[25] J. M. Clough, C. Kilchoer, B. D. Wilts, and C. Weder, “Hierarchically Structured Deformation-Sensing Mechanochromic Pigments,” Advanced Science 10, no. 13 (2023): 2206416.

[26] W. Zhu, S. Takeuchi, S. Imai, et al., “Chemigenetic Indicators Based on Synthetic Chelators and Green Fluorescent Protein,” Nature Chemical Biology 19, no. 1 (2023): 38–44.

[27] H. Chen, K. Shou, S. Chen, et al, “Amphiphilic Cyclopeptide-Dyes: Smart Self-Assembly Amphiphilic Cyclopeptide-Dye for Near-Infrared Window-ii Imaging,” Advance Materials 33, no. 16 (2021): 2170121.

[28] P. Cheng, Y. Peng, S. Li, et al., “3D Printed Continuous Fiber Reinforced Composite Lightweight Structures: A Review and Outlook,” Composites Part B: Engineering 250 (2023): 110450.

[29] X. Fan, Y. Fang, W. Zhou, et al., “Mussel Foot Protein Inspired Tough Tissue-Selective Underwater Adhesive Hydrogel,” Materials Horizons 8, no. 3 (2021): 997–1007.

[30] H. Qiu, W. Ni, L. Yang, and Q. Zhang, “Remarkable Ability of Pb(II) Capture From Water by Self-Assembled Metal-Phenolic Networks Prepared With Tannic Acid and Ferric Ions,” Chemical Engineering Journal 450 (2022): 138161.

[31] L. Sun, H. Huang, L. Zhang, et al., “Spider-Silk-Inspired Tough, Self-Healing, and Melt-Spinnable Ionogels,” Advanced Science 11, no. 3 (2024): 2305697.

[32] J. Y. Kasper, M. W. Laschke, M. Koch, et al., “Actin-Templated Structures: Nature's Way to Hierarchical Surface Patterns (Gecko's Setae as Case Study),” Advanced Science 11, no. 10 (2024): 2303816.

[33] Q. Xu, M. Xu, C.-Y. Lin, et al., “Metal Coordination-Mediated Functional Grading and Self-Healing in Mussel Byssus Cuticle,” Advanced Science 6, no. 23 (2019): 1902043.

[34] W. Zhang, R. Wang, Z. Sun, et al., “Catechol-Functionalized Hydrogels: Biomimetic Design, Adhesion Mechanism, and Biomedical Applications,” Chemical Society Reviews 49, no. 2 (2020): 433–464.

[35] X. Guo, X. Zhao, L. Yuan, et al., “Bioinspired Injectable Polyurethane Underwater Adhesive With Fast Bonding and Hemostatic Properties,” Advanced Science 11, no. 16 (2024): 2308538.

[36] T. Mao, H. Feng, J. Wu, et al., “Waterborne Organic Silicone Polyurethane With Excellent Self-Healing Performance for Oil/Water-Separation and Oil-Recovery Applications,” Sustainable Materials and Technologies 36 (2023): e00631.

[37] M. W. M. Tan, P. M. Thornton, G. Thangavel, H. Bark, R. Dauskardt, and P. S. Lee, “Toughening Self-Healing Elastomers With Chain Mobility,” Advanced Science 11, no. 30 (2024): 2308154.

[38] X. Zhu, W. Zhang, G. Lu, H. Zhao, and L. Wang, “Ultrahigh Mechanical Strength and Robust Room-Temperature Self-Healing Properties of a Polyurethane–Graphene Oxide Network Resulting From Multiple Dynamic Bonds,” ACS Nano 16, no. 10 (2022): 16724–16735.

[39] J. R. Pathan, H. Balan, P. Commins, et al., “A Self-Healing Crystal That Repairs Multiple Cracks,” Journal of the American Chemical Society 146, no. 39 (2024): 27100–27108.

[40] X. Wang, J. Xu, Y. Zhang, et al., “A Stretchable, Mechanically Robust Polymer Exhibiting Shape-Memory-Assisted Self-Healing and Clustering-Triggered Emission,” Nature Communications 14, no. 1 (2023): 4712.

[41] Y. Lv, C. Li, Z. Yang, et al., “Monomer Trapping Synthesis Toward Dynamic Nanoconfinement Self-Healing Eutectogels for Strain Sensing,” Advanced Science 11, no. 42 (2024): 2410446.

[42] H. Xu, S. Zhao, A. Yuan, et al., “Exploring Self-Healing and Switchable Adhesives Based on Multi-Level Dynamic Stable Structure,” Small 19, no. 26 (2023): 2300626.

[43] D. Wang, J. Xu, J. Chen, et al., “Transparent, Mechanically Strong, Extremely Tough, Self-Recoverable, Healable Supramolecular Elastomers Facilely Fabricated via Dynamic Hard Domains Design for Multifunctional Applications,” Advanced Functional Materials 30, no. 3 (2020): 1907109.

[44] Z. Ping, F. Xie, X. Gong, et al., “Tailoring Photoweldable Shape Memory Polyurethane With Intrinsic Photothermal/Fluorescence via Engineering Metal-Phenolic Systems,” Advanced Functional Materials 34, no. 38 (2024): 2402592.

[45] H. Feng, T. Wang, W. Wang, C. Ma, Y. Pu, and S. Chen, “High Efficiency Photothermal Cyclic Self-Healing Antibacterial Coating Based on In-Situ Dual-Functional BiOI@Bi₂S₃,” Journal of Materials Science & Technology 173 (2024): 121–136.

[46] N. Xu, A. Hu, X. Pu, et al., “Fe(III)-Chelated Polydopamine Nanoparticles for Synergistic Tumor Therapies of Enhanced Photothermal Ablation and Antitumor Immune Activation,” ACS Applied Materials & Interfaces 14, no. 14 (2022): 15894–15910.

[47] X. Zou, X. Wang, S. Sun, et al., “Shape-Adaptive Underwater Adhesive Based on Supramolecular Assembly for Robustly Integrated Underwater Wireless Sensing/Communication and Bioelectronic Adhesion,” Nano Today 56 (2024): 102282.

[48] X. Zhao, Y. Liang, Y. Huang, J. He, Y. Han, and B. Guo, “Physical Double-Network Hydrogel Adhesives With Rapid Shape Adaptability, Fast Self-Healing, Antioxidant and NIR/pH Stimulus-Responsiveness for Multidrug-Resistant Bacterial Infection and Removable Wound Dressing,” Advanced Functional Materials 30, no. 17 (2020): 1910748.

[49] D. Zhou, S. Li, M. Pei, et al., “Dopamine-Modified Hyaluronic Acid Hydrogel Adhesives With Fast-Forming and High Tissue Adhesion,” ACS Applied Materials & Interfaces 12, no. 16 (2020): 18225–18234.

[50] T. Shi, H. Lu, J. Zhu, et al., “Naturally Derived Dual Dynamic Crosslinked Multifunctional Hydrogel for Diabetic Wound Healing,” Composites Part B: Engineering 257 (2023): 110687.

[51] X. Yao, W. Hu, Y. Li, et al., “Dual Dynamic Crosslinked Hydrogel Patch Embodied With Anti-Bacterial and Macrophage Regulatory Properties for Synergistic Prevention of Peritendinous Adhesion,” Advanced Functional Materials 34, no. 34 (2024): 2400660.

[52] Q. Yang, Y. Zhong, Z. Zhang, Z. Dang, F. Li, and L. Zhang, “Distinguished Adsorption Behaviors and Micro-Mechanisms of Cr(Ⅵ) Onto Mesoporous Polydopamine With Different Pore Architectures: Classical Theory and Electron-Scale Perspectives,” Separation and Purification Technology 354 (2025): 129002.

[53] H. Hu, P. F. Popp, M. Santiveri, et al., “Ion Selectivity and Rotor Coupling of the Vibrio flagellar Sodium-Driven Stator Unit,” Nature Communications 14, no. 1 (2023): 4411.

[54] A. Docker, I. Marques, H. Kuhn, Z. Zhang, V. Félix, and P. D. Beer, “Selective Potassium Chloride Recognition, Sensing, Extraction, and Transport Using a Chalcogen-Bonding Heteroditopic Receptor,” Journal of the American Chemical Society 144, no. 32 (2022): 14778–14789.

[55] Y. Qiang, L. Guo, H. Li, and X. Lan, “Fabrication of Environmentally Friendly Losartan Potassium Film for Corrosion Inhibition of Mild Steel in HCl Medium,” Chemical Engineering Journal 406 (2021): 126863.

[56] G. Chilkoor, K. Jawaharraj, B. Vemuri, et al., “Hexagonal Boron Nitride for Sulfur Corrosion Inhibition,” ACS Nano 14, no. 11 (2020): 14809–14819.

[57] J. Wang, F. G. Gámez, J. Marín-Beloqui, et al., “Cover Picture: Synthesis of a Dicyclohepta[a,g]Heptalene-Containing Polycyclic Conjugated Hydrocarbon and the Impact of Non-Alternant Topologies,” Angewandte Chemie International Edition 62, no. 10 (2023): e202217124.

[58] M. Li, L. Tong, X. Li, et al., “Enhanced Intrinsic Self-Healing Performance of Mussel Inspired Coating via In-Situ Cation Capture,” Small 20, no. 37 (2024): 2311658.

[59] A. Jangde, S. Kumar, and C. Blawert, “Correlative Study of Mott-Schottky Analysis and Corrosion Behaviour of Plasma Electrolytic Oxidation Treated Magnesium Alloy: Effect of Cl^─ Concentrations,” Corrosion Science 240 (2024): 112386.

[60] C. Liu, L. Cheng, L.-Y. Cui, P. Hou, B. Qian, and R.-C. Zeng, “Robust Damage Warning and Healing Tracing Strategy for Anticorrosion Coatings on Magnesium Alloy AZ31 enabled by Polydopamine Fluorophores,” Journal of Materials Science & Technology 152 (2023): 169–180.

[61] C. Liu, P. Hou, B. Qian, and X. Hu, “Smart Healable and Reportable Anticorrosion Coating Based on Halloysite Nanotubes Carrying 8-Hydroxyquinoline on Steel,” Journal of Industrial and Engineering Chemistry 118 (2023): 109–118.

[62] X. Zhu, W. Zheng, H. Zhao, and L. Wang, “Non-Covalent Assembly of a Super-Tough, Highly Stretchable and Environmentally Adaptable Self-Healing Material Inspired by Nacre,” Journal of Materials Chemistry A 9, no. 36 (2021): 20737–20747.

[63] Z. Wang and Y. Li, “Drop-Weight Impact and Compressive Properties of Repeatable Self-Healing Carbon Fiber Reinforced Composites,” Composites Part B: Engineering 283 (2024): 111626.

[64] M. W. M. Tan, G. Thangavel, and P. S. Lee, “Rugged Soft Robots Using Tough, Stretchable, and Self-Healable Adhesive Elastomers,” Advanced Functional Materials 31, no. 34 (2021): 2103097.

[65] H. Chen, Z. Sun, H. Lin, C. He, and D. Mao, “Neuron Inspired All-Around Universal Telechelic Polyurea With High Stiffness, Excellent Crack Tolerance, Record-High Adhesion, Outstanding Triboelectricity, and AIE Fluorescence,” Advanced Functional Materials 32, no. 36 (2022): 2204263.

[66] R. Zhao, Z. Zhao, S. Song, and Y. Wang, “Multifunctional Conductive Double-Network Hydrogel Sensors for Multiscale Motion Detection and Temperature Monitoring,” ACS Applied Materials & Interfaces 15, no. 51 (2023): 59854–59865.

[67] Y. Ou, Y. Xing, Z. Yang, et al., “Strong and Ultrafast Stimulus-Healable Lignin-Based Composite Elastomers With Excellent Adhesion Properties,” International Journal of Biological Macromolecules 256 (2024): 128507.

[68] Y. Yao, Z. Xu, B. Liu, M. Xiao, J. Yang, and W. Liu, “Multiple H-Bonding Chain Extender-Based Ultrastiff Thermoplastic Polyurethanes With Autonomous Self-Healability, Solvent-Free Adhesiveness, and AIE Fluorescence,” Advanced Functional Materials 31, no. 4 (2021): 2006944.

RIGHTS & PERMISSIONS

2025 The Author(s). SmartMat published by Tianjin University and John Wiley & Sons Australia, Ltd.