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This paper presents a reliable nanolithography technique, namely dynamic plowing lithography (DPL) based on a commercial atomic force microscope (AFM). The poly(methyl methacrylate) (PMMA) solution spinning on a silicon substrate is utilized to be scratched directly with an oscillating tip at its resonance frequency. The films with different thickness are obtained by adjusting the concentration of solution and post baked time. A new silicon tip is employed to conduct DPL on PMMA film surface. The geometry of nano-line structure scratched on the film with high adhesion force is shown with a transition process, including total protuberance, protuberance with groove and groove with pile-up. The scratching direction has less influence on the scratched depth of groove, while the shape of pile-up is varied with directions. The depth of groove on thin films is increasing with the drive amplitude until the value of the depth reaches to the threshold value. Moreover, owing to smaller elastic modulus, the film with relatively large thickness could be modified by the tip more easily using this DPL method. SCANNING 38:612-618, 2016. © 2016 Wiley Periodicals, Inc.

Summary Due to the tip-sample interaction which is the measurement principle of Atomic Force Microscope (AFM), tip wear constantly occurs during scanning. The blunt tip caused by the wear process makes more tip geometry information involved in the image, and correspondingly it increases the measurement error. In the present study, the scan parameters of AFM in tapping mode which affect the wear of single crystal silicon tips, such as the approaching rate, the scan rate, the scan amplitude, and the integral gain are investigated. By proposing a parameter reflecting the imaging quality, the tip state tracing the sample surface is evaluated quantitatively. The influences of scan parameters on this imaging quality parameter are obtained by experiments. Finally, in order to achieve the perfect images with little tip wear influence, tip wear experiments are carried out and then the optimal parameter settings which can lighten the tip wear are obtained. SCANNING 36:263–269, 2014. © 2013 Wiley Periodicals, Inc.

Summary Nanobundles patterns can be formed on the surface of most thermoplastic polymers when the atomic force microscope (AFM)-based nanomechanical machining method is employed to scratch their surfaces. Such patterns are reviewed as three-dimensional sine-wave structures. In the present study, the single-line scratch test is used firstly to study different removal states of the polystyrene (PS) polymer with different molecular weights (MWs). Effects of the scratching direction and the scratching velocity on deformation of the PS film and the state of the removed materials are also investigated. Single-wear box test is then employed to study the possibility of forming bundle structures on PS films with different MWs. The experimental results show that the state between the tip and the sample plays a key role in the nano machining process. If the contact radius between the AFM tip and the polymer surface is larger than the chain end-to-end distance, it is designated as the “cutting” state that means the area of both side ridges is less than the area of the groove and materials are removed. If the contact radius is less than the chain end-to-end distance, it is designated as the “plowing” state that means the area of both side ridges is larger than the area of the groove and no materials are removed at all. For the perfect bundles formation on the PS film, the plowing state is ideal condition for the larger MW polymers because of the chains’ entanglement. SCANNING 35:308-315, 2013. © 2012 Wiley Periodicals, Inc.

Nanoscale materials directly interfacing semiconductors is a new area of nanoscience and nanotechnology. Tremendous attention has been paid to inorganic nano size crystals in recent years because of their significant properties. Prussian blue (PB) and its analogues could play important roles in the field of molecule-based magnets, electrochromic materials, ion selectivity electrodes and biosensors. In this study, we report on fabricating Prussian blue patterns on silicon surface by combining the photolithographic techniques and galvanic displacement reaction, and the resulting patterns were characterized by scanning electron microscopy (SEM) and scanning electrochemical microscopy (SECM) on the basis of detection of catalytic current for the oxidation of H 2 O 2 .

To function properly in the rigorous tissue environment, implanted scaffolds for tissue engineering are required to meet certain standards of strength and mechanical integrity. However, the soft nature and moisture condition of biomaterials impose great challenges to many existing techniques and instrumentations for measuring their mechanical properties at micro/nano scale. In this work, we demonstrate the testing methodologies of micro/nano fiber reinforced type I collagens, and obtain basic mechanical property data of two types of modified collagens-micro carbon fiber reinforced collagen (MCFR) and nano collagen fiber reinforced collagen (NCFR). Results show that mechanical properties of collagen tissues can be enhanced by reinforcing nano collagen fibers but weakened by micro carbon fiber reinforcements. Mechanisms are discussed on how natures of reinforcing fibers affect reinforcement to the collagen matrix, as well as how reinforcements behave within the collagen matrix in response to mechanical strain.