The bumps have a low modulus and the hollows have a
high modulus, which also could be attributed to the tip-induced cracks formation. Therefore, the mechanism for the occurrence of such rippling structures can be presumed as an interaction of stick-slip and crack formation processes. Figure 5 Schematic of the ripple formation mechanisms by an AFM tip. (a) Schematic of the bump formation with many cracks and (b) the cartoon model for the ripple formation. (c) AFM morphology, (d) modulus image, and www.selleckchem.com/products/PF-2341066.html (e) cross-sections of a ripple structure. (f) The topography and (g) modulus image of a 3D nanodots structure. Conclusions Directional ripple patterns with perfect periodicity can be formed on PC surfaces by scratching zigzag patterns with an AFM tip. The range of normal load and feed used for ripple formation can be obtained to modulate the period of the ripples. By combining scratching angles of 90° and 0°, beta-catenin signaling 90° and 45°, and 0° and 45° in two-step machining, we fabricated nanoscale dot and diamond-dot structures with controlled size and orientation. The typical rippling of the polymer surface can be presumed as a stick-slip and crack formation process. This study reveals that AFM-based nanomachining can be used to fabricate controllable complex 3D nanoripples and nanodot arrays on PC surfaces.
Acknowledgment The authors gratefully acknowledge the financial supports of National Science Foundation of China (51275114, 51222504), Program for New Century Excellent Talents in University (NCET-11-0812), Heilongjiang Postdoctoral Foundation of China (LBH-Q12079), and the Fundamental Research Funds for the Central Universities (HIT.BRETIV.2013.08). References 1. Mccrum NG, Buckley CP, Bucknall CB: Principles of Polymer Engineering. New York: Oxford University Press; 1997:34–88. 2.
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