One of the essential technologies used to fabricate nanoscale structures is atomic force microscopy (AFM), which is a tip-based nanomechanical machining method that possesses the advantages of precise spatial MDV3100 clinical trial resolution, in situ imaging, and other unique features, including the inexpensive device, relatively easy control and operation [4]. Especially, the AFM-based friction-induced nanomechanical method, which belongs to one of the AFM-based nanofabrication methods, is looked on as a new way for forming complex nanostructures [5, 6]. Ripple patterns can exist over a range of length scales including macroscopic linear ripples on sea and desert sands

created by wind [7], microsized ripples on surfaces of metal substrates produced by ion sputtering [8], and nanoscale ripples on the surfaces of thermoplastic polymers obtained by an atomic force microscope (AFM) tip’s reciprocal scanning [9]. In particular, it ZD1839 clinical trial has been found that ripples can be formed on polymer surfaces by single scanning with an AFM tip. Acunto et al. [10, 11] reported that ripple patterns could be formed with a small applied load and single scanning on the surfaces of solvent-containing

polyethylene terephthalate (PET) films. Gnecco et al. [12] reported that linear ripples with the period of 100 to several hundreds of nanometers can be produced by a heated AFM tip on the surfaces of polycarbonate (PC), poly (methyl methacrylate) (PMMA), and PSul films, and the ripples could also be obtained with circular scanning. The main mechanisms for the tip-induced ripple formation including Schallamach waves, stick-slip, and fracture-based deformation [9, 13, 14] have been proposed. The Schallamach waves are reviewed as the inability of the rubber surface Cell press under high shear forces [9]. The stick-slip JNK inhibitor solubility dmso mechanism is the competition between the tangential force and the critical tangential force [13]. And, the fracture-based deformation is perceived as the existence of the cracks in the deformed materials [14]. All of the mechanisms are just the proposed model. They cannot be clearly conformed and came to an agreement

for explaining the ripples’ formation. So, the mechanism for the process of such ripple formation is still controversial. As mentioned above, just simple ripple-based structures had been formed by AFM tip’s scanning. And, for the novel friction-induced mechanical nanofabrication method, only the protrusive nanostructures including nanodots, nanolines, surface mesas, and nanowards have been produced by the mechanical interaction on the material surface. Until now, complex, ordered nanostructures on polymer surfaces using the friction-induced direct nanofabrication method are not reported [5, 6]. In previous work, we produced nanoscale ripples by scratching a PC surface with an AFM tip with a hard cantilever once [15].