Hexagonal Structure Enhancing Damping Efficiency Inspired by Tree Frogs

Magnetic fluid shock absorbers (MFSAs) have been successfully applied in eliminating the micro-vibration of the spacecraft’s flexible structures. The method of enhancing the damping of MFSAs has always been the key issue. The tree frog’s toe pads exhibit the strong adhesion, which inspired us to learn from their surface structure. We got hundreds of scanning electron microscope images of the tree frog’s toe pads surface and used the edge extraction algorithm to obtain the result that the geometric shape with the largest proportion in these images is hexagon. According to this result, hexagonal surface textures were added to the inner surface of the MFSA and a small part of the MFSA was taken for further simulation analysis. The flow distribution of the magnetic fluid (MF) acquired from the simulation clearly illustrates that the surface textures cause vortexes formation in the MF layer. These vortexes increase the shear rate between the MF layers, thereby augmenting the flow resistance. The vibration reduction experiments were carried out and MFSAs employed in these experiments were fabricated by 3D printing technology. Consequently, the bionic textures mimicking the tree frog’s toe pads surface can significantly improve the damping performance of MFSAs.