Recent standardization activities on data treatment and management for scanning probe microscopy (SPM), performed in ISO TC 201, are reviewed. International Standard ISO 28600 on standard data transfer format for SPM is introduced. The data conversion software compatible with ISO 28600 will facilitate inter-exchangeability and consistent treatment of data, enhance productivity of data-processing programs, and increase accuracy and quantification. Once the data format has been standardized, the focus should shift to standardizing data-processing procedures such as drift correction, probe-tip characterization, and image restoration. To make SPMs reliable tools for nanometrology, standardization of quantitative image restoration is necessary. A solution relying on mathematical morphology is introduced to reduce artifacts caused by probe shape. The use of well-characterized probes with known probe shapes is critical to accurate reconstruction of topography images. Our final goal is establishment of a comprehensive SPM database integrated with a common data-processing environment.
The current status of quantitative elastic modulus evaluation of soft-materials, which is based on atomic force microscopy, is described together with planned ISO standardization activity. Force-displacement curves on the surfaces of soft-materials are measured in this procedure. The emphasis will be placed on how Hertz or Derjaguin-Muller-Toporov (DMT) contact mechanics fails to fit the experimental curves and alternatively how Johnson-Kendall-Roberts (JKR) model can solve the problem. To obtain a two-dimensional map of elastic modulus based on the above-mentioned analysis, so-called force-volume technique is employed. Several examples will be shown including vulcanized isoprene rubber and high-density polyethylene.
Scanning probe microscopy (SPM) is a powerful tool to characterize the nanomaterial properties, such as surface morphology, electronic structure, elasticity, ..., etc. However, the SPM image is the dilation of probe shape and specimen geometry. For precise measurement of nano-structure, calibration of SPM instrument, especially for the probe tip and cantilever, is very important. Efforts for the determination of these properties, such as spring constant of the cantilever, probe shape, including international standardization are reported.
This study investigated the removal of glass spheres from the surface of a silicon substrate by using electrostatic adhesion force. An upper silicon electrode and a dielectric film, such as polyethylene (PE) and polyvinylchloride, were placed on a lower silicon electrode to which the glass spheres were adhered, and a high voltage was applied to the two silicon electrodes for about 60 s. Glass spheres with a diameter of 0.105-0.125 mm were removed by the PE film at voltage of over 500 V, but those with a diameter of 0.04-0.09 mm showed low removal rates. The dielectric film could not contact smaller glass spheres deposited near larger ones, which lowered the removal force for the smaller spheres. Repeating the removal process showed a high removal rate of about 90% after the fifth iteration with an applied voltage of 2,510 V. This means that the largest glass spheres were removed by the first process, and the smaller ones were removed by the subsequent processes.
It is known that the performance of lithium ion batteries deteriorates as number of cycles increases. In order to investigate the reason for this the deterioration, the surface coverage of film formation was measured for graphite electrodes with different stages of number of cycles. Simultaneously, the gas desorption amount was measured. As the number of cycles increased, so did the surface coverage. The gas desorption amount was roughly proportional to the surface coverage. A polymer-coating changes the characteristics of the film, battery performance and gas desorption. These results suggest that deterioration in the battery performance is owing to film formation because the film blocks lithium ion flow at the graphite surface. The expansion of the battery case is owing to gas desorption from the surface film. In this study, the reasons for battery performance are clarified.