Manufacturing of Bionic Adhesion Microstructure with Expanded Ends Based on Electroplating in the Restricted Area

The organisms of animals with full spatial motion ability present fine and complex 3D structures, showing reliable adhesion ability to the substrate. As core issues, the design and manufacture of complex morphology are essential in bionic adhesion technology. Specifically, the end-expanded microstructure array of high adhesion under low preload has widespread potential in the nondestructive fixation and handling of fragile objects. In the fabrication of end-expanded microstructures, the design and manufacture of metal molds with good mechanical strength are the key. In this paper, a microfabrication technology for manufacturing nickel molds based on three-dimensional printing and electroplating was proposed. The effect of the electric field inhomogeneity on the electrodeposition morphology was systematically studied. Typical bionic adhesives with expanded ends were obtained by a roll-to-roll hot embossing (R2R-HE) process. The normal adhesion force of the bionic adhesives is 9.5 N/cm², which is comparable to that of the gecko. The electroplating process assisted by 3D printing provides a new approach for the fabrication of complex bionic morphologies and large-area bionic adhesion structures.