Sticking/Climbing Ability And Morphology Studies Of The Chinese Fire Belly Newt

After millions of years of natural selection in nature, many creatures have evolved in a lot of specialized organ to adapt to the living environment which can avoid predators and be hunt for food, such as lotus’ s surface, gecko’s foot, shark’s skin, tree frog’s toe pad and newt’s toe pad etc. many scholars at home and abrod have done a lot of research about the specail functional structure in these creatures, finding that their special features of the surface have corresponding special microstructure. Inspired by nature, people committed to these micro-structure with special features to the actual structure of the surface, in order to solve practical problems of production and life. This article will test the sticking/climbing ability of the Chinese fire belly newt by experiment, and launched detailed research on its toe pad and belly skin surface’s micro- and nano- strcuture, and conduct a detailed analysis of its adhesion mechanism.This article test the sticking/climbing ability of the Chinese fire belly newt by a self-made experimental device. Glass, PMMA(Polymethylmethacrylate), Polytetrafluoroethylene and SUS 304 stainless steel are the tested surface, and processing the rough surface on one of its surface. Surface roughness, the amount of water, contact angle and the weight of newt are experimental variations. The sticking/climbing ability of the Chinese fire bellt newt was tested by these experimental variations. The micro- and nano-strcuture on the Chinese fire belly newt toe pad and belly skin surface was observed by the SEM(scanning electron microscopy) and cryo-SEM(low temperature scanning electron microscopy), and the adhesion mechanism of the different micro-strcuture of the toe pad and belly skin surface was elaborated. The main conclusions of this article are as follows:1. In the sticking experiment, the surface roughness, the amount of water and the wettability are the greater factors. These three factors can influence the real contact area, adhesive force and the detaching angle. Among these factors, the detaching angle is the highest when the Chinese fire belly newt is lighter and the surface is smooth with little water on it.2. In the climbing experiment, because of the Chinese fire belly newt’s status of sticking and climbing are different, the result of detaching angle in climbing experiment showed some difference with that in sticking experiment. And the difference between sticking and climbing experiment is that the result of smooth and rough surface is just opposite.3. The micro-strcuture on toe pad and belly skin surface of Chinese fire belly newt has a clear distinction. The toe pad is consist of about 20 to 30 micrometers in diameter polygonal epithelial, separated by the cell borders. On each epithelial, there are about 100 to 300 nanometers dense nanopillars. These nanopillars should be the main strcuture to help promote the rapid adhesion by the capillary force on the surface, and can squeezed out water between the groove on the water surface. Although the belly skin surface of the Chinese fire belly newt has the similar polygonal epithelial cells, the nano-strcuture on each epithelial cell is dense nano-pore.