Dr. Liu Zeng Gan discovered for the first time that panda teeth can repair themselves. According to Liu Zeng Gan, the minerals in the teeth of giant pandas are vertically and closely arranged like trees, thus forming a "solid forest" of enamel, and organic substances are filled in tiny gaps between "mineral trees". The deformation, damage and automatic recovery of enamel are realized through this tiny gap.

The natural organic matter at the interface of panda's enamel will swell under hydration conditions, and then the polymer chain flexibility will increase and the glass transition temperature will decrease, so as to realize the self-repair of enamel. The water molecules in panda's saliva can significantly promote the self-repair effect.

The final research results of Dr. Liu Zeng Gan's research team

It is found that the self-healing of giant panda's teeth is mainly due to the high interstitial density and ingenious tissue structure of minerals rich in organic matter in its enamel.

The research team put forward the concept and design principle of structural orientation gradient of new materials for the first time, that is, by adjusting the orientation relationship between its own organizational structure and external force, the tensile and compressive properties of materials can be realized, thus improving the overall mechanical properties of materials.

In addition, the research team also clarified the main types, morphology and organizational structure characteristics of panda teeth, and revealed the performance optimization mechanism of them with both offensive and protective functions from the perspective of material science and mechanics, thus refining the design principles of bionic materials.