Firstly

monodisperse polystyrene (PS) microspheres with different diameters are prepared.Subsequently

a uniform and smooth Pt film is formed on the PS microsphere surface by ion sputtering

yielding the corresponding PS-Pt core-shell composite microsphere.Finally

surface wrinkling on these PS composite microspheres is induced by solvent swelling.Consequently

PS microspheres with various surface wrinkle patterns are obtained.Hereinto

the effects of experimental parameters (e.g.

Pt film thickness

microsphere diameter and the swelling solvent) on the surface wrinkling behaviors have been investigated systematically.The results reveal that whether the surface wrinkling on the composite microspheres takes place or not

the resulting wrinkling morphologies are determined by the overstress R/cR. Here the overstress can be tuned by the Pt film thickness

microsphere diameter and the swelling degree.It is noted that a power-law dependence of the wrinkling wavelength on Pt film thickness is obtained and the experimental results are in agreement with the results of the theoretical simulation and calculation.Additionally

combining surface wrinkling and surface plasma etching technique

PS microspheres with composite morphologies of nano-protrusion and wrinkles have been prepared by exposure of PS microspheres to oxygen plasma before ion sputtering of the Pt film.It is envisioned that the introduced strategy in principle could be applied to other curved surfaces for expeditious generation of well-defined wrinkle morphologies

which enables not only the fabrication of solids with multifunctional surface properties

but also provides important implications for the morphogenesis in soft materials and tissues.