LI XueyuAssistant Professor

Laboratory of Soft & Wet Matter
Research Theme
fatigue and fracture mechanism of tough and self-healing hydrogels
Research Keywords

fatigue and fracture, crack propagation, phase separation, Rheological response, hierarchical structure, tough hydrogels

Overview of Research

(1) Muscles, composed of exquisite hierarchical structures, exhibit high fatigue resistance and can resist crack propagation even after injury. The mechanism of the hierarchical structures on suppressing crack advance under reciprocating movement is poorly understood. Tough and self-healing hydrogels are good candidates as simplified model systems for studying the mechanical behaviors of load-bearing bio-tissues. By tuning the hierarchical structure in tough and self-healing hydrogels (such as polyampholyte hydrogels), we have discovered that the bicontinuous phase networks at the 100-nm scale notably decelerates the crack propagation in tough hydrogel, and clarified the role of hierarchical structure on the multi-level fatigue resistance. Further studies will incorporate muscle-like hierarchical structures in the hydrogels to achieve fatigue-resistant and self-healing under physiological conditions, and explore their applications in emerging fields such as biomedicine, tissue engineering, etc.

(2) Viscoelasticity, derived from noncovalent/reversible interactions in covalent polymer networks, is a phenomenon commonly observed in soft materials, such as elastomers, hydrogels and human tissues. Viscoelastic dissipation associated with the rheological response of these noncovalent/reversible interactions plays an essential role in the toughness enhancement and crack resistance. But its effect on fatigue behavior, particularly the fatigue threshold for vanishing crack advancing velocities, is still an open question. Therefore, we will study the relationship between viscoelastic response and fatigue resistance in tough and self-healing hydrogels.



Self-healing hydrogels have a high similarity to bio-tissues in structural and mechanical properties. If you are interested in the mechanism of high stretchability, strong fatigue-resistance, and self-healing of biotissue-like soft materials, please don’t hesitate to contact us.

Representative Publications

X. Li, J. P. Gong, Role of dynamic bonds on fatigue threshold of tough hydrogels. Proc. Natl. Acad. Sci. U.S.A. 119, e2200678119 (2022).

X. Li, F. Luo, T. L. Sun, K. Cui, R. Watanabe, T. Nakajima, J. P. Gong, Effect of Salt on Dynamic Mechanical Behaviors of Polyampholyte Hydrogels. Macromolecules 56, 535–544 (2023).

X. Li, K. Cui, T. Kurokawa, Y. N. Ye, T. L. Sun, C. Yu, C. Creton, and J. P. Gong. Effect of Mesoscale Phase Contrast on Fatigue-Delaying Behavior of Self-Healing Hydrogels. Sci. Adv., 2021, 7: eabe8210.

X. Li, K. Cui, T. L Sun, L. Meng, C. Yu, L. Li, C. Creton, T. Kurokawa, and J. P. Gong. Mesoscale Bicontinuous Networks in Self-Healing Hydrogels Delay Fatigue Fracture. Proc. Natl. Acad. Sci. U.S.A., 2020, 117(14): 7606.

K. Cui, Y. N. Ye, C. Yu, X. Li, T. Kurokawa, and J. P. Gong. Stress Relaxation and Underlying Structure Evolution in Tough and Self-Healing Hydrogels. ACS Macro Lett., 2020, 9(11): 1582.

Refer to researchmap


<Office Hour>
– Time: Anytime during the lecture period
– Place: Frontier-AMLS, 3F
Please contact in advance by E-mail.
E-mail: lixueyu[at]