Harvard Professor SUO Zhigang Unveils Frontiers in Soft Materials, Bio-adhesion and Biomedical Applications

On 2 June 2026, Prof. SUO Zhigang, Foreign Member of Chinese Academy of Sciences, Member of both National Academy of Engineering and National Academy of Sciences in the USA, Allen E. and Marilyn M. Puckett Professor of Mechanics and Materials at Harvard University, USA, delivered a PAIR Distinguished Lecture titled “Adhesion between Soft Materials and Tissues” at the PolyU campus. The lecture was attended by more than 100 scholars, researchers and students in person, and nearly 16,000 online viewers across various social media platforms.

During the lecture, Prof. Suo first explained the fundamental mechanics of hydrogels, illustrating how two brittle polymer networks — polyacrylamide and alginate — can be combined to form a highly tough and stretchable hybrid hydrogel. This “brittle + brittle = tough” design concept greatly enhances the material’s resistance to fracture through hysteresis and viscoelastic energy dissipation, increasing its fracture energy from approximately 10 J/m² to over 9,000 J/m². These advanced hydrogels also possess desirable properties such as stretchability, transparency and conductivity, enabling their use as ionic conductors in various biomimetic devices, including artificial muscles, stretchable electroluminescent devices and ionic transistors, thereby overcoming the fragility limitations of conventional biocompatible materials.

In the area of interface engineering, Prof. Suo further elaborated on how the synergistic interplay among chemistry, topology and mechanics enables robust tissue adhesion. He introduced pioneering techniques such as “topological adhesion” and “molecular staples”, which utilise biocompatible polymers to form instant, tough and non-covalent bonds on soft tissue surfaces. His research team has also successfully developed innovative materials, including “hydrogel paints” and photodegradable adhesives, which not only provide strong adhesive performance but can also be safely removed under ultraviolet (UV) light, offering breakthrough solutions for clinical applications such as surgical dressings and wound care.

The lecture also highlighted the translational applications of these materials in both biomedical and industrial fields. Prof. Suo introduced hydrogel-mesh composites designed for sutureless adhesive anastomosis in organ transplantation, a technology that can significantly reduce surgical trauma and the risk of fluid leakage. He further explained how the mechanical principle of multiscale stress deconcentration can increase the fatigue threshold of soft materials by tenfold. Beyond bioimplants, this concept has also been extended to the development of sustainable engineering materials, such as “green tyres” made from silica-filled natural rubber and highly durable natural rubber tanglemers.

The lecture concluded with an interactive Q&A session moderated by Prof. MAI Yiu-wing, PolyU Distinguished Chair Professor of Composites Science and Engineering. Prof. ZHENG Zijian, Vice President (Knowledge Transfer) of PolyU, Prof. SU Zhongqing, Head and Chair Professor of Smart Structures and Systems of the Department of Mechanical Engineering, together with faculty members and students, actively participated in the discussion. Online audiences also responded enthusiastically, engaging in in-depth exchanges on a range of cutting-edge academic topics, including how hydration layers at the interface between soft materials and living tissues influence transient adhesion strength, as well as the design of intelligent soft adhesives capable of controllable detachment in response to physiological microenvironmental changes such as pH, temperature and reactive oxygen species. The event fostered a vibrant atmosphere for academic exchange both onsite and online.