With the development of Micro-Electro-Mechanical-Systems(MEMS),the microscale flow characteristics had attracted the great interests of scientific researchers. The key question is whether the macro flow rules are still valid or the micro flow has its own special flow characteristics which can be altered from the macro flow rules or it is a whole new theory. All these questions must be experimented to gain the final result. In this paper, the behavior of liquid was studied in microchannels with diameters ranging from 13 mu m to 100 mu m. By using different microtube diameter and length to explore the flow characteristics of microfluids. The results are basically in accordance with macroscale conventional theory; the N-S equation still acts well.

Diamond-like carbon (DLC) film composed of microscopically insulation but microscopically a mixture of conducting (sp^2) and insulating (sp^3) phases was discussed on the local modification with a conductive atomic force microscope (C-AFM). Especially, a topographic change was observed when a direct current (DC) bias-voltage was applied to the DLC film. Experimental results show that a nanoscale pit on DLC surface was formed when applying a positive 25 V on DLC film. According to the interacting force between CoCr-coated microelectronic scanning probe (MESP) tip and DLC surface, as well as the Sondheimer oscillation theory, the scalewing effect of the pit was explained. Electromechanical coupling on DLC film suggested that the depth of pits increased with an increase of load applied to surface when the cantilever-deflected signal was less than a certain threshold voltage.

Tribological characteristic of different thick diamond-like carbon (DLC) films was studied. A geometrical method was applied to calibrate the cantilever spring constant and, to calculate the normal and lateral forces, respectively. Experimental results show that the lateral force under different applied loads is proportional to the normal force for the DLC films with the thickness of 153.4nm and 64.9nm. However, for the thickness of 4.48nm and 2.78nm DLC films, lateral force is nonlinear to normal force, which is opposed to the Amonton's law. The single asperity regime and the DMT model were put forward to predict, the possible nanotribological mechanisin between the probe and DLC film.

In order to decrease cutting fluid and improve environment, the cutting fluid was replaced by solid lubricant. Four kinds of solid lubricants were tested on a high temperature friction tester, from which nano K 2Ti 4O 9 whisker enhanced solid lubrication film was chosen. It was coated on the surface of cutters and tested on a CA6140 lathe. At the rate of 400r/min, the wear of the tool flank with solid lubrication film is 1/6 of that without the film, and it is even lower than that using cutting fluid. With the increase of cutting speed, the wear of the tool flank with solid lubrication film is still lower than that without film, but it is higher than that using cutting fluid. Surface analyses by AFM, SEM and EDX reveal that the solid lubrication film can prevent Fe element of chips from diffusing the cutter surface; adhesion of the cutter and chips is abated and the wear of the tool flank is obviously decreased.