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This paper investigates nanomachining of single-crystal silicon using an atomic force microscope with a diamond-tip cantilever To enable nanomachining of silicon, a nanomachining cantilever with a pyramidal diamond tip was developed using a combination of photolithography and hot-filament chemical vapor deposition. Nanomachining experiments on silicon using the cantilever are demonstrated under various machining parameters. The silicon surface can be removed with a rate of several tens to hundreds of nanometers in ductile mode, and the cantilever shows superior wear resistance. The experiments demonstrate successful nanomachining of single-crystal silicon. [DOI: 10.1115/1.2163364] Keywords: nanomachining, atomic force microscope, cantilever, single-crystal silicon

A major cause of magnetic spacing losses in data tape systems is pole tip recession (PTR). This study is an investigation of PTR in a linear data tape recording system and identification of the mechanisms responsible for these effects, but the results have implications for any head where the tape bearing surface is [Al.sub.2][O.sub.3]/TiC, AlTiC. Tape cycling experiments were performed using the linear tape open system as the experimental platform with metal particle tape. All experiments were conducted within a matrix of pressure and humidity, which encompassed the system operating extremes. Atomic force microscopy was used to analyze the surface topography of the heads. Auger electron spectroscopy and x-ray photoelectron spectroscopy were employed to analyze the chemical changes on the surface of the heads and tapes. Environment was found to have a significant influence on the head/tape interface. Head wear and PTR was highest at high temperature and humidity. Water vapor was found to transform the surface layers on the TiC grains in the tape-bearing surface to Ti[O.sub.2]. This process results in the production of Ti[O.sub.2] fragments that become trapped in the recessed pole tip region, acting as three-body abrasive particles. The Ti[O.sub.2] present on the TiC grains and on the surface of heads increases with the water content after cycling against tapes. The hypothesis is supported by the presence of Ti on the poles.

Dynamic numerical simulation of a protein-ligand molecular chain connected to a moving atomic force microscope (AFM) has been studied. A sinusoidal base excitation of the cantilevered beam of the AFM is considered in some detail. A comparison between results for a single molecule and those for multiple molecules has been made. For a small number of molecules, multiple stable static equilibrium positions are observed and chaotic behavior may be generated via a period-doubling cascade for harmonic base excitation of the AFM. For many molecules in the chain, only a single static equilibrium position exists. To enable these calculations, reduced-order (dynamic) models are constructed for fully linear, combined linear/nonlinear and fully nonlinear systems. Several distinct reduced-order models have been developed that offer the option of increased computational efficiency at the price of greater effort to construct the particular reduced-order model. The agreement between the original and reduced-order models (ROM) is very good even when only one mode is included in the ROM for either the fully linear or combined linear/nonlinear systems provided the excitation frequency is lower than the fundamental natural frequency of the linear system. The computational advantage of the reduced-order model is clear from the results presented.

The objective of this paper is to formulate the equations of motion and to investigate the vibrations of the atomic force microscope (AFM), which is divided into the contact and noncontact types. First, the governing equations of the AFM including both base oscillator and piezoelectric actuator are obtained using Hamilton's principle. In the dynamic analysis, the piezoelectric layer is treated as a sensor to measure the deflection and as an actuator to excite the AFM via an external voltage. The repulsive force and van der Waals (vdW) force are considered in the contact and noncontact types of the AFM, respectively. Some important observations are made from the governing equations and boundary conditions. Finally numerical results using a finite element method are provided to illustrate the excitation effects of base oscillator and piezoelectric actuator on the dynamic responses. [DOI: 10.1115/1.1389084]

Roughness measurements of a magnetic tape, a biaxially oriented poly (ethylene terephthalate) (PET) substrate, a tape head and a rigid-disk slider were made by an atomic force microscope (AFM) and a non-contact optical profiler (NOP). The lateral resolution of the surface topographs ranges from 1 Micrometer (for NOP) down to 1 nm (for AFM). The AFM images show submicron features of the surface that are characteristic of the manufacturing processes. Some of the statistical roughness parameters conventionally used in theories of contact mechanics showed strong dependence on instrument resolution. This suggests that, firstly, roughness measured by NOP at resolutions larger than 1 Micrometer cannot be used to study tribology at submicrometer scales and, secondly, a scale-independent characterization by fractal geometry is necessary. Fractal analysis of the tape surface reveals two regimes of roughness demarcated by a scale of 0.1 Micrometer corresponding to the size of magnetic particles. The fractal behavior explains the dependence of the rms height, slope and curvature on the instrument resolution. The predictions of real area of contact suggest that nanometer-scale asperities tend to deform plastically whereas micrometer-scale ones deform elastically.