Inspired by the fascinating adhesive and cold-tolerant properties of spider silks, Chinese researchers led by Prof. WANG Shutao from the Technical Institute of Physics and Chemistry (TIPC) of the Chinese Academy of Sciences (CAS) have recently proposed a spider-silk-inspired wet adhesive. The adhesive is composed of core–sheath nanostructured fibers with hygroscopic adhesive nanosheath and supporting nanocore, showing robust wet adhesion and supercold tolerance. 

The study, published in Advanced Materials, has demonstrated the promising applicability of this spider-silk-inspired adhesives in cryogenic environments. It also provides an innovative route to design functional wet adhesives.  

Nowadays, the adhesive materials are applied in various fields, facing more complex environments like polar adventure, aerospace and cold supply chain. However, achieving or maintaining high adhesion performance in complex environments remains a major challenge for the developed adhesives.  

Scientists observed that spiders can capture prey under the roof or along the lake with their capture silks. Besides, the dragline silks of spider exhibit high mechanical property at very low temperature. With the inspiration of spider, Prof. WANG's team designed their work.  

The researchers found that the adhesion performance of this spider-silk-inspired adhesive could be optimized by regulating the water content, the wettability of the adhered surface and the diameter of supporting nanocores.   

To further demonstrate the promising applicability of the wet adhesive in cryogenic environments, they adhered this spider-silk-inspired adhesive on different objects, such as fresh apple, frozen meat package, cryo-tube, and even metal box with cryopreserved cells and stored them in their corresponding store temperature.

As a result, it maintained reliable adhesion in their corresponding store temperature (from 4 to -196 °C) and further tolerated disturbances in liquid nitrogen (-196 °C). 

"The study may provide a new design principle to fabricate functional adhesives to meet requirements of extreme environments, and also promote developing in spider-silk-inspired materials and other new wet adhesive materials," said Prof. WANG.

This work was supported by the National Key R&D Program, the National Natural Science Foundation of China, and the National Program for Special Support of Eminent Professionals of Organization Department of the CPC Central Committee.

Spider-Silk- Inspired Wet Adhesive Demonstrates Universal Wet Adhesion with Supercold Tolerance. (Image by WANG et al.)