Design, experiment and adsorption mechanism analysis of bionic sucker based on octopus sucker

The vacuum chuck is widely used in industrial and daily life. By observing the macroscopic and microscopic morphology of octopus sucker, it is found that the sucker surface has concave-convex continuous wave shape with large number of non-smooth morphologies. The sealing mechanism of octopus sucker is analyzed according to its surface morphology before and after adsorption, and the non-smooth morphology is found to greatly enhance the adsorption. Based on the bionics theory, the non-smooth surface morphology of octopus sucker is applied to improve the sucker adsorption. And the bionic suckers with three types of grooves are designed. According to the model of standard and bionic suckers, the sucker entities are obtained by the method of three-dimensional printing and casting. And the tensile tests of suckers are carried out. The stress of suckers is analyzed by finite element method, and the sealing mechanism is discussed. According to the test results, the bionic sucker has larger adsorption force. And the ring sucker possesses the best adsorption performance. Compared with the standard sucker, the maximum adsorption force of the bionic sucker is increased by 12.2% in the air and 25.2% underwater. The adsorption force of bionic sucker becomes larger with the increase in the groove number; when the groove number increases to a certain extent, the adsorption force becomes smaller. The deformation of non-smooth morphology during adsorption makes the bionic sucker have a larger contact area. That is the reason why the bionic sucker has good adsorption performance. The bionic design of sucker can provide a new method to improve its adsorption.