Buckling‐Pattern‐Based Characterization of Stiff Membrane on Soft Film

Abstract

Stiff and soft bilayer systems are commonly used in industrial and biological applications. A classical stiff/soft bilayer film is an oxygen‐plasma‐treated polydimethylsiloxane (PDMS) film. After treatment, the PDMS film surface is oxidized, and then the stiff oxide surface layer and residual soft PDMS layer jointly constitute bilayer films, which are crucial materials in the fields of flexible electronics and buckling behavior studies. However, the oxidized surface layer is not properly recognized because of the complexity of the oxidization transition induced by the oxygen plasma. Here, its atomic composition and ratio are experimentally determined. A calculation approach to calculate its thickness and modulus based on the buckling behaviors of bilayer films is proposed. An accurate modulus of the oxide layer, 34.6 GPa, is obtained. Furthermore, this method can be used to characterize various stiff films in bilayer systems, which shows great potential for applications in many fields.

Periodic fracture behaviour of nanomembranes

“…In this chapter, we prepared a bilayer film by treating a poly (dimethylsiloxane) (PDMS) film with oxygen (O 2 ) plasma 23 (see Methods and Materials). The O 2 plasma treatment could oxidize the PDMS film surface and generate a stiff silicon oxide layer 27,28 (Fig. S3a, ESI †).…”

“…The wrinkle holds a certain surface parameter, which equals intrinsic periodic length l 0 at the threshold of the wrinkling instability. l 0 is proportional to the thickness of the stiff membrane t m , expressed as l 0 = At m , where A is a constant related to elastic properties of the bilayer 28,32,33 (Supplemental theoretical analysis, S2.1). Therefore, facture period l is equal to 2l 0 and can be tuneable depending on t m , as shown in Fig.…”